Show 1420: The Cooking Oil Controversy Spotlights Cancer (Archive)

This week, we dig into the cooking oil controversy. For decades, we’ve heard that we should be using vegetable oils rather than butter, lard or other fats (possibly even olive oil). Oils from corn, soybeans, sunflower or safflower seeds are rich in polyunsaturated fatty acids. Consequently, people consuming them may have lower cholesterol levels than those primarily using saturated fats. But could there be a downside? We hear from scientists who have found these seed oils may be linked to certain cancers.

You could listen through your local public radio station or get the live stream at 7 am EDT on your computer or smart phone (wunc.org).  Here is a link  so you can find which stations carry our broadcast. If you can’t listen to the broadcast, you may wish to hear the podcast later. You can subscribe through your favorite podcast provider, download the mp3 using the link at the bottom of the page, or listen to the stream on this post starting on March 3, 2025.

The Cooking Oil Controversy:

The more we learn about fats, the more it seems that focusing on just one aspect may be too simplistic. In the 1990s, health experts told Americans to avoid all fat. When it became clear that low-fat diets were not necessarily making everyone healthy, we got the message that we needed to stick with polyunsaturated fatty acids (PUFAs) like those in corn or canola oil. There are, however, different types of PUFA. Chemists classify them as omega-3, omega-6 and omega-9 fatty acids. Only omega-3 and omega-6 are considered essential fatty acids.

Current cooking oils have a preponderance of omega-6 fatty acids. As a result, the ratio of omega-6 to omega-3 in our blood has risen from a pre-industrial average of an estimated 4:1 to our current ratios of 20:1 (Missouri Medicine, Sep-Oct. 2021).  This could have biological consequences.

Dietary Fat and Cancer:

Dr. William Aronson has asked how different types of dietary fat affect the progression of prostate cancer. Laboratory studies show that a diet high in corn oil accelerates the growth of human prostate cancer tumors implanted under the skin of mice. That inspired him and his colleagues to conduct a randomized controlled trial (Journal of Clinical Oncology, Dec. 13, 2024).

Fish Oil vs. Prostate Cancer:

For their trial, they recruited 100 men diagnosed with prostate cancer who opted for active surveillance rather than immediate surgery or radiation. They assigned these volunteers to different diets for one year. One group followed their usual diet and did not take fish oil. The researchers instructed the other group in avoiding omega-6 fats in their diet, increasing the amount of omega-3 rich fish and taking fish oil supplements. Minimizing omega-6 fats meant staying away from fried foods, cooking oils, bottled salad dressing and mayonnaise. At the end of the year, there was a significant difference in an important prostate cancer biomarker called Ki-67.

Does the Cooking Oil Controversy Extend to Other Cancers?

We spoke with Dr. Timothy Yeatman about his research on colorectal tumors. His research was published in Gut, a leading journal for gastroenterologists (Dec. 20, 2024). He and his colleagues used a technique called lipidomics for their analysis. They found that the lipid profile of the tumors and their micro-environments is pro-inflammatory. They seem to lack the resolving mediators (“resolvins”) that should normally accompany healing. The balance has been disrupted.

Dr. Yeatman suspects that some of this disruption may be due to changes in the microbiome that constitutes a lot of the immediate environment for colorectal tumors. He suggests that extensive use of seed oils high in pro-inflammatory omega-6 fatty acids may contribute to the imbalance. You can find soybean oil, for example, in many foods where you might not expect it, such as breads, cakes, cookies, crackers, chips and even hummus. Cooking at home allows people to avoid seed oils, but it takes time, skills and resources that are not available to everyone.

Can We Resolve the Cooking Oil Controversy?

Neither of the studies we discuss during this episode is definitive. Scientists need more research to be able to make solidly evidence-based recommendations. However, both our guests would suggest we need not wait for the final word to reduce the inflammatory potential of our diets. Reading labels carefully is a good first step to avoiding some of the seed oils that provide excess omega-6 fats and gravitate more toward omega-3 fats.

This Week’s Guests:

William Aronson, MD, is Professor in the Department of Urology of the David Geffen School of Medicine at the University of California, Los Angeles. He is also Chief of Urologic Oncology at the West Los Angeles Veterans Affairs Medical Center and Chief of Urology at the Olive View-UCLA Medical Center.

Timothy Yeatman, MD, FACS, is Professor in the Dept of Surgery at the University of South Florida. He is also Associate Center Director for Translational Science and Innovation Tampa General Hospital Cancer Institute. His website is https://phenomehealth.org/c-suite/tim-yeatman-md-facs

Debora Melo vanLent, PhD, is Assistant Professor at the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health in San Antonio, TX. Her interview is part of the podcast.

Listen to the Podcast:

The podcast of this program will be available Monday, March 3, 2025, after broadcast on March 1. You can stream the show from this site and download the podcast for free. In addition to what you heard in the broadcast, the podcast also includes our discussion with Dr. Melo vanLent on her research into the link between dietary inflammation and dementia.

Download the mp3, or listen to the podcast on Apple Podcasts or Spotify.

Transcript of Show 1420:

A transcript of this show was created using automated speech-to-text software (AI-powered transcription), then carefully reviewed and edited for clarity. While we’ve done our best to ensure both readability and accuracy, please keep in mind that some mistakes may remain. If you have any questions regarding the content of this show, we encourage you to review the original audio recording. This transcript is copyrighted material, all rights reserved. No part of this transcript may be reproduced, distributed, or transmitted in any form without prior written permission.

Joe

00:00-00:01

I’m Joe Graedon.

Terry

00:01-00:05

And I’m Terry Graedon. Welcome to this podcast of The People’s Pharmacy.

Joe

00:06-00:27

You can find previous podcasts and more information on a range of health topics at peoplespharmacy.com. Inexpensive cooking oils from corn, peanuts, soy, or sunflower seeds are popular. Are they as healthy as people think? This is The People’s Pharmacy with Terry and Joe Graedon.

Terry

00:34-00:49

For decades, Americans were urged to trade in their butter and even olive oil for polyunsaturated vegetable oils. Is there an unexpected downside for consuming so much omega-6 fatty acids relative to omega-3 fats?

Joe

00:50-00:56

Recent research links high omega-6 consumption to a higher risk of certain cancers.

Terry

00:57-01:02

We’ll talk with two scientists about the links between seed oils and prostate and colorectal cancer.

Joe

01:03-01:09

Coming up on The People’s Pharmacy, the cooking oil controversy spotlights cancer.

Terry

01:14-02:02

In The People’s Pharmacy Health Headlines: Doctors once thought that Alzheimer’s disease resulted from an unfortunate combination of bad luck and aging. In recent years, though, evidence has been growing that the amyloid plaque building up in the brains of dementia patients might be an immune response to infection.

Researchers conducted a randomized controlled trial of the antiviral medicine valacyclovir among 120 people with early Alzheimer’s disease and evidence of herpes infection. The trial lasted a year and a half and used an objective 11-item rating scale to measure response. The report published in JAMA notes that valacyclovir was not efficacious to prevent further cognitive decline (JAMA, Dec. 17, 2025). It can’t be recommended against Alzheimer’s disease.

Joe

02:03-03:00

Tramadol has become one of the most prescribed pain medicines in the U.S. It’s a dual-action drug with some opioid-like qualities along with some antidepressant activity. That’s because it affects neurotransmitters like serotonin and norepinephrine. When tramadol was introduced as Ultram, the manufacturer suggested that this pain reliever would be better than opioids.

Danish researchers recently conducted a meta-analysis and review of 19 randomized placebo-controlled clinical trials involving over 6,000 participants. Their conclusion: “Tramadol may have a slight effect on reducing chronic pain levels while likely increasing the risk of both serious and non-serious adverse events. The potential harms associated with tramadol use for pain management likely outweigh its limited benefits.” (BMJ Evidence-Based Medicine, Oct. 7, 2025).

Terry

03:00-03:35

Some experts on Alzheimer’s disease have pointed out that the brains of these patients don’t use glucose efficiently. Research published in JAMA Network Open utilized Medicare data to compare outcomes of people with dementia and diabetes treated with insulin (JAMA Network Open, Dec. 1, 2025).

One group tested their own blood sugar periodically with a finger stick. The other group used continuous glucose monitors. The records show that those on continuous glucose monitors were significantly less likely to be hospitalized and less likely to die during the study period.

Joe

03:37-04:33

Parkinson’s disease has been increasing at an alarming rate. Researchers believe that environmental toxins, especially pesticides, could be contributing (JAMA Network Open, May 1, 2025). The authors performed a case-control study involving over 400 individuals with PD. They were matched to more than 5,000 healthy controls of similar ages and sex. The investigators mapped geographic location of the volunteers’ homes. Those living within one mile of a golf course had a 126% increased chance of developing Parkinson’s disease compared to those living more than six miles from a course.

The authors conclude that these findings suggest that pesticides applied to golf courses may play a role in the incidence of PD for nearby residents. The researchers speculate that chemical runoff and groundwater contamination could be important factors.

Terry

04:33-05:17

Chronic low-grade inflammation is associated with a range of metabolic problems, including insulin resistance that could eventually develop into type 2 diabetes. Researchers have found a surprising way to fight inflammation and improve insulin sensitivity: fresh mangoes (Nutrients, Jan. 29, 2025).

48 overweight people were randomly assigned to eat 100 calories of fresh mangoes or an equal caloric amount of Italian ice every day for a month. Two cups of mango provides approximately 100 calories. When the study ended, the mango eaters had significantly lower levels of insulin in response to a glucose tolerance test. Those in the control group had no changes in their response.

Joe

05:19-05:54

GLP-1 receptor agonists are among the most talked about drugs in the country, if not in the world. That’s because they are surprisingly effective at helping people lose weight. But what happens when people stop?

An analysis of the SURMOUNT-4 trial revealed that most people regained weight (JAMA Internal Medicine, Nov. 24, 2025). Half added about half the weight they had lost, and one in four people regained most of the weight they had lost.

And that’s the health news from the People’s Pharmacy this week.

Terry

06:14-06:16

Welcome to The People’s Pharmacy. I’m Terry Graedon.

Joe

06:16-06:39

And I’m Joe Graedon. For decades, nutrition experts have told us that we should avoid saturated fat and substitute vegetable oils like corn, sunflower, safflower, canola, and soybean oils. Cardiologists love these cooking oils because they can lower cholesterol, but are there some unforeseen risks?

Terry

06:39-07:09

These seed oils are rich in polyunsaturated omega-6 fatty acids. For a long time, the focus was on the fact that they are polyunsaturated. More recently, though, some scientists have begun to examine the balance between the omega-6 and omega-3 fats. How healthy are these PUFAs in cooking oil from seeds? Is there an unanticipated cancer risk associated with excessive omega-6 fatty acid consumption?

Joe

07:09-07:28

To find out, we turn to Dr. William Aronson. He’s a professor in the Department of Urology and Chief of Urology at Olive View UCLA Medical Center. Dr. Aronson is also Chief of Urologic Oncology at the West Los Angeles Veterans Affairs Medical Center.

Terry

07:29-07:32

Welcome to the People’s Pharmacy, Dr. William Aronson.

Dr. William Aronson

07:33-07:42

Hi, guys. I’m looking forward to chatting about our research. I’m a longtime NPR listener, and looking forward to a great morning with you guys.

Joe

07:43-08:12

Thank you so much. Dr. Aronson, we get asked questions all the time about diet. What should we eat? What should we avoid? And there’s been so much conflicting information when it comes to oils and fats, and in particular, a relationship to cancer. So could you tell us a little bit about what prompted your CAPFISH3 randomized clinical trial and what you learned?

Dr. William Aronson

08:14-08:50

A little over 30 years ago, I went to a meeting where a very prominent prostate cancer professor presented data in which he showed that if in human prostate cancers grown under the skin of mice, if you lowered the fat that was given to the mice, it markedly reduced the progression of those prostate tumors as compared to the high-fat diet. And so it was that initial look at that data which really got my interest spurred in this field.

Joe

08:50-08:52

Where did you go from there?

Dr. William Aronson

08:52-09:16

From that point on, we’ve done a number of studies in both animal models and a number of studies in patients with prostate cancer that have shown remarkable effects with regards to different types of dietary fat and how they affect progression of the prostate cancer.

Joe

09:18-09:27

Well, fast forward three decades, and now we have CAPFISH, C-A-P-F-I-S-H-3. What did you learn?

Dr. William Aronson

09:28-10:28

So [I’m] going to take a little step back though before… What we, before getting into this trial, we’ve done studies on omega-6 and omega-3 fats and how they affect prostate cancer growth.

So there’s three types of fats. There’s the saturated fat, the monounsaturated fat, and the polyunsaturated fat. And our interest has been in the polyunsaturated fats, specifically the omega-3 fats, which we can get from specific fish. And there’s also other sources as well.

And then we’ve been very interested in the omega-6 polyunsaturated fats, which no one has ever really heard of that term. But that refers to the fats like the seed oils. So for example, corn oil, sunflower oil, safflower oil, and even grapeseed oil.

Terry

10:29-10:33

So those are the ones that a lot of people actually are eating a lot of.

Dr. William Aronson

10:35-11:14

Oh, it’s predominant in the American diet. And when we did studies in mice, we found that when we gave them corn oil, it rapidly accelerated the growth of human prostate cancers in mice, whereas we could inhibit that or slow the growth when we put in a more favorable ratio of the omega-3 to the omega-6 fatty acids.

That’s what then led us, those types of studies that we did in the lab, to then conducting this larger one-year trial that we just completed and reported out on.

Terry

11:15-11:24

Tell us a little bit about how the trial was designed. Who participated, and what were the differences in the way that they were treated?

Dr. William Aronson

11:26-13:25

So we enrolled… there were 100 men that completed the trial. These were men with prostate cancer that were diagnosed with prostate cancer on a prostate biopsy. And all of these men elected active surveillance instead of undergoing treatment like radical prostatectomy or radiation therapy. It turns out that if you have a slower or slightly slower growing type of prostate cancer, that’s a very standard option to choose.

And so these men elected after their initial biopsy to enter our trial and then have another biopsy of their cancer one year later. And these men, we randomly assigned them to one of two groups. In one group, we let the men know they could eat whatever they wanted, but not to take fish oil capsules over that one year period.

The other group, we had them see a dietitian once a month. And that dietitian worked with the patients to markedly lower their omega-6 intake. So that would be reducing, for example, fried foods, reducing foods with corn oil, safflower oil, reducing, for example, mayonnaise, reducing salad dressings that are bottled.

And so these men in that group lowered the omega-6 level. It was a fish-based diet, so they ate plenty of fish providing the omega-3 fatty acids, like salmon, for example, and tuna. And that group also received fish oil capsules. So these were the two treatment arms in our study.

Terry

13:25-13:28

What were the consequences?

Dr. William Aronson

13:29-15:09

So the primary endpoint of our study, the key thing that we wanted to look at was a biomarker called Ki-67. So Ki-67 is a protein on the surface of cells, specifically in the case of prostate cancer.

If prostate cancer is expressing or showing this Ki-67, it means that the cancer cells are dividing. So the main thing that we looked at was the Ki-67 levels in both groups to see if there was a difference between the groups. What we know from prior studies is if you look at Ki-67 in men with prostate cancer, the higher the Ki-67, the more cancer cells that are dividing, and the more likely that those men with high Ki-67 levels are going to have progression of their cancer, spread of their cancer, and even more likely to have death from their prostate cancer. So this was the key marker that we looked at was the Ki-67.

And what we found was that the Ki-67 was reduced in the group that got the low omega-6, high omega-3 fish diet with fish oil capsules. And it was increased in the group that ate whatever they wanted to and didn’t take fish oil capsules. And there was a significant difference between the groups with regards to this biomarker called Ki-67.

Joe

15:11-15:15

So the take-home message from your research, Dr. Aronson?

Dr. William Aronson

15:17-17:18

So the take-home message is that, firstly, this was a phase two trial. There’s phase one trials, phase two trials, and phase three trials. Phase three trials would require a much larger patient population. We had about 100 patients. And phase three trials would be required to look at specific clinical endpoints, like, for example, aggressiveness of the cancer or progression of the cancer.

Ours was a phase two trial (Journal of Clinical Oncology, March 2025). We did see a significant effect on this biomarker called Ki-67. We did not see a significant effect in our small trial on, for example, Gleason grade, which is known to predict prostate cancer progression. Our trial was not designed to look at Gleason grade. It was specifically designed to look at Ki-67.

And so the conclusion from the trial is we saw a significant effect as a result of the diet plus the fish oil on Ki-67. And that is an important biomarker for prostate cancer. It’s now left to the decision-making of the patients or their families of men with prostate cancer, and it’s left at the discretion of the clinicians who treat prostate cancer if they want to apply this information to their patients.

What I know is that literally every patient that I see with a new diagnosis of prostate cancer wants to know if they should change their diet, what they can do for themselves. And so at that point, I’m going to let them know about the results of the study, and then it will really be up to the patients if they want to make any changes or not. I suspect that they will.

Terry

17:19-17:24

Dr. William Aronson, thank you very much for talking with us on The People’s Pharmacy today.

Dr. William Aronson

17:27-17:34

It’s been a pleasure speaking with you guys. I love listening to your podcast, and thanks for the invitation.

Terry

17:35-17:52

You’ve been listening to Dr. William Aronson, professor in the Department of Urology at UCLA and chief of urology at Olive View UCLA Medical Center. He’s chief of urologic oncology at the West Los Angeles Veterans Affairs Medical Center.

Joe

17:52-17:59

After the break, we’ll speak with Dr. Timothy Yeatman about his research on the effect of seed oils.

Terry

17:59-18:06

Most of these oils have long been considered to have anti-inflammatory effects. Do they deserve that reputation?

Joe

18:06-18:11

What do we mean by omega-3 and omega-6 fats? How are they different?

Terry

18:11-18:17

Why is the ratio of omega-3 to omega-6 so important?

Joe

18:18-18:25

Dr. Yeatman will describe his research on the links between seed oils and colorectal cancer.

Terry

18:38-18:54

You’re listening to The People’s Pharmacy with Joe and Terry Graedon. Welcome back to The People’s Pharmacy. I’m Terry Graedon.

Joe

18:54-19:12

And I’m Joe Graedon.

Terry

19:12-19:34

Today, we’re looking at the possible connections between popular cooking oils and the risk of cancer. We just heard from Dr. William Aronson about his research linking omega-6 fatty acids to a biomarker for prostate cancer. It’s time to find out why the ratio of omega-6 fats to omega-3 fats is important.

Joe

19:35-19:52

We turn now to Dr. Timothy Yeatman. He is a professor in the Department of Surgery at the University of South Florida. Dr. Yeatman is also Associate Center Director for Translational Science and Innovation at Tampa General Hospital Cancer Institute.

Terry

19:53-19:56

Welcome to the People’s Pharmacy, Dr. Timothy Yeatman.

Dr. Timothy Yeatman

19:57-20:01

Thank you. I’m happy to be here to talk about a very exciting topic today.

Joe

20:02-20:47

Oh, it is indeed exciting. And Dr. Yeatman, I have to tell you that we are very impressed with your research. But first, basics. Vegetable oils, they’re supposed to be good for us. We sauté with vegetable oils, we bake with vegetable oils, we put vegetable oils on our dressing.

Seed oils are found in chips and crackers and dips and all kinds of other foods. We’re talking about safflower, peanut, canola, corn, sunflower, soybean, sesame oils, and they’re all considered by the cardiovascular community as anti-inflammatories. Do these oils merit this halo?

Dr. Timothy Yeatman

20:49-22:01

Well, I don’t think they do for a number of reasons. First of all, I’m not sure the entire cardiology community agrees with your statement because more recent data is coming out demonstrating a pro-inflammatory nature of a number of these oils.

Now, granted, they are, in fact, essential oils, essential fatty acids that you have to take in through your diet. So the only way you can get them is through diet. And they’re essential for making your cell walls, membranes, and so forth.

But the question is, how much is too much and what is the right amount? My grandmother used to say, do everything in moderation. And what’s happened since I think about 1967 going forward, there’s been a massive onslaught of an overabundance of these seed oils in the diet.

And what that’s done has changed the omega-6 to omega-3 ratios in people from maybe an ideal of one-to-one or four-to-one to like 25-to-one or 30-to-one. And we know that populations like, you know, the Inuits would have a much different ratio because they’re on a completely different diet.

Terry

22:01-22:10

I wonder if you could explain to us, please, what we mean by omega-6 and omega-3 and why that ratio might be important.

Dr. Timothy Yeatman

22:11-24:23

So the omega-3 is easy because you think of that as, people think of that as equivalent to fish oil. And there’s DHA and EPA components to it, and they vary. And some of those components are thought to be good for the heart and the brain, and some are thought to be good to prevent cancer. But that’s omega-3s coming mostly from good nuts like walnuts and almonds and pistachios and things like that, and also from fish. The small fish are probably better than the large fish, because they don’t have the mercury, but, you know, the larger fish, halibut, salmon have large levels of omega-3 and the smaller fish anchovies, sardines and things have high levels of omega-3.

But the omega-6s are composed of linoleic acid or things that can be derived from what we call seeds or seed oils. So canola oil, safflower oil, sunflower oil, et cetera. And they’re high in the omega-6.

Now, truth be told, most oils are a mixture of omega-6 and omega-3s, and most foodstuffs are that way. For example, red meat. You can get red meat that is grain-fed beef that is a ratio of 25 to 30 to 1, omega-6 to omega-3. But grass-fed beef, grass-fed butter, grass-fed milk is 1 to 1.

So there are big differences in the omega-6s to the omega-3s in the foods that we eat. And if you consume too much of the omega-6s, your ratio becomes imbalanced.

Now, why is that important? Well, I think one of the most significant studies is recent, where they looked at the UK Biobank and looked at thousands of patients over a period of time and found that people who had a higher omega-6 to omega-3 ratio had a significantly higher all-cause mortality rate and cancer rate and other rates of inflammatory diseases (eLife, April 5, 2024). So we think, and our laboratory believes, that it’s the ratio that’s important, not just the individual levels of omega-3 or omega-6.

Terry

24:23-24:44

Well, I’m hoping that you will tell us about your recent research that was published in the journal Gut, talking about the connection, potential connection between consumption of seed oils and the tumors that you found in people with colorectal cancer.

Dr. Timothy Yeatman

24:45-27:32

Yeah, so the paper, by the way, got a remarkable response. According to Gut, it’s in the top 5% of all papers that are published with responses to it. The reason it was so popular was because I think we found a smoking gun.

We identified in tumors versus normal adjacent mucosal samples from the same patients that there was a significant elevation of pro-inflammatory lipid mediators (Gut, Dec. 20, 2024). And these are the leukotrienes, the LTB4, LTC4, [LTD4]. And there was a dearth of the pro-resolving molecules.

We now know that wound healing is a combination of inflammation first, followed by resolution of inflammation. And we think that’s occurred over eons of time. That has developed as a defense mechanism against bacterial infections and viral infections, which probably killed most prehistoric people, as well as trauma.

But if you think about that, if cancer is a model for wound healing, then it’s clear that cancer appears to be a poorly healing wound because it’s chronically inflamed and doesn’t resolve the inflammation. When you get a cut on your hand, I always say that you’ll see first swelling and redness, and that’s because of the influx of inflammatory cells. But as that inflammation resolves, the redness goes away, so does the swelling.

Well, you have to say, why does that happen? Is that just magical? No, it’s not. It’s because the body has an active resolution process called resolution of inflammation. And it’s also performed by lipid mediators, but this time they’re called lipoxins, resolvins, maresins, and protectins. So the body has a host of pro-inflammatory lipid mediators derived from the lipids we eat and pro-resolving lipid mediators derived from the lipids we eat.

So you can imagine if you ate far more pro-inflammatory lipids, you’d get more pro-inflammatory mediators. Because actually the same enzymes that convert lipids into lipid mediators that are pro-inflammatory are the same ones that do it for the pro-resolving lipid mediators. The difference is enzymes work based on substrate availability. So if you have a lot more omega-6 substrate for the enzyme to work on, it’s going to make a lot more of the inflammatory byproduct. If you have more pro-resolving substrate like omega-3 in your body, those same enzymes will work to make resolving lipid mediators.

Joe

27:34-27:45

So, Dr. Yeatman, we’ll get back to your research in a moment because you’re a surgeon and you were removing tissue from colon cancers. Is that right?

Dr. Timothy Yeatman

27:45-27:47

Mm-hmmm, it is.

Joe

27:46-28:58

But first, let’s dig a little deeper into biochemistry. So you’ve really set this up beautifully, but I think a lot of people go, “Oh, what’s he talking about?” Leukotrienes, protectins, resolvins, big words. So let’s start with the biochemistry and make it even more complicated.

If you’re consuming a lot of omega-6 fatty acids from the seed oils that you’ve already mentioned, like safflower, peanut, canola, corn, sunflower, soybean, sesame. What you’ve got is linoleic acid and then arachidonic acid, all converted into leukotrienes and prostaglandins, like thromboxanes, that are inflammatory. That’s the output.

Whereas if we’re consuming omega-3s, they’re converted into alpha-linolenic instead of linoleic and to EPA, eicosapentaenoic acid, DHA, ducoso… hi, help me here, Terry, DHA?

Terry

28:58-29:00

Docosahexaenoic acid.

Joe

29:00-29:08

…which are then converted to those protectins and resolvins that are anti-inflammatory. Have I got that right?

Dr. Timothy Yeatman

29:08-29:09

You did. That was perfect.

Joe

29:10-29:33

So when we’re eating all those chips and all those ultra processed foods, we’re inevitably getting a lot of omega-6 fatty acids, which are going to lead to inflammation. That doesn’t sound like a good thing in our gut, but it doesn’t sound like a good thing in our brain or any other part of our bodies.

Dr. Timothy Yeatman

29:34-30:50

That’s correct. And, you know, I kind of believe now that inflammation is the root cause of many diseases, whether it’s cancer or Alzheimer’s or diabetes or arthritis or stroke or heart attack. But if you think about cancer, take it down to the cellular level like we’re talking about.

Let’s say you have that first cell in a crypt, in the villus of the colon mucosal wall that gets a spontaneous mutation. We know that our colon is lined with billions and billions of cells. And every day there are probably, you know, many, many mutations. I don’t know the number, but many mutations occurring naturally. And those mutations are checked by specific genes and processes that are in place.

But you can imagine if your immune surveillance system that’s normally active and would normally shut down all those mutations is less active or turned down by a pro-inflammatory process, that you may be more apt to allow a new mutation to take foothold. And so I think of cancer not only now as a genetic disease, but also a metabolic disease.

Joe

30:53-31:46

Well, that makes total sense to me. And I like to make things understandable to our listeners. And one of the ways that I like to do that is with specifics.

So if we think about guacamole and chips, because that’s the way we consume our guacamole. The guacamole is made from avocados, and avocados are presumably rich in omega-3 fatty acids.

The chips, on the other hand, whether we like it or not, are ultra-processed foods, and they might have omega-6 fatty acids in the way they’re made. So if we eat a whole bunch of guacamole, it’s probably anti-inflammatory.

But if we have just a little bit of guacamole and a lot of chips, it’s probably more pro-inflammatory with more omega-6 fatty acids. Is that a fair representation?

Dr. Timothy Yeatman

31:47-34:12

It is, but I would broaden this to say, you know, when you go to the grocery store and you’re looking at food labels, which you should start doing, you’ll find that soybean oil has infiltrated many different foodstuffs you wouldn’t suspect it to be in. For example, it’s in a lot of bread. It’s in a lot of, it’s in almost all cakes, pies, cookies, and things. But also, surprisingly, it’s very hard to find hummus without soybean oil in it. So it’s amazing that it’s really in many things we eat that are processed.

And what we also know today, and we haven’t discussed this much, but there is a clear interaction between what we take in and our microbiome. Now, I used to think that the microbiome would be just sort of static in your gut, but in fact, it’s very responsive to the food you eat. It’s much like adding a weed killer. If you kill some weeds, others grow up. If you fertilize, the grass may grow.

So when you fertilize with omega-6, you’re likely to get different bacteria in your gut than if you fertilize with omega-3. And people are looking at ketogenic diets in that way now and saying, huh, I wonder if ketogenic diets, they seem to work in some cancers to help them. Wonder why they work… Is it possible that when you have a ketogenic diet, you actually, you know, rebalance your omega-6 to omega-3 because of what you’re eating?

So, you know, I started to ask all these questions myself and wondering what the interactions are between the lipids and the microbiome. We know that from animal models where omega-6 is overrepresented, it changes the gut microbiome substantially. So now you have different bugs in your gut doing different things. And what havoc does that wreak on the body?

So if that’s lipids, what about all the other things in processed foods? You know, we know that, for instance, some simple things like sorbitol, which is a sweetener that’s now…. artificial sweetener, sugar rather, than every, almost every artificial drink today, that dramatically changes the microbiome. And so if that can do that, what is, you know, what do the dyes do? What do the preservatives do? What do all these things do to our body? I mean, a lot of the things we have never looked at that. It’s just never been checked.

Terry

34:14-34:35

Well, Dr. Yeatman, one of the things that really caught our eye and perhaps some of the other folks who’ve been looking at your study that was published in Gut is that there’s been a real increase in colon cancer in younger people, people under 50. Do you think all of these things are related to that?

Dr. Timothy Yeatman

34:37-36:08

Well, it could be. And I say that cautiously because, you know, we don’t have evidence. But, you know, I’ve said before that it was very hard to prove that cigarettes cause cancer, you know, because there were some people who smoked their whole life and never got cancer. But most of them died from COPD or strokes or heart attacks, right? So it did cause problems, but not everybody got cancer. So to cause an effect is always difficult to prove.

But, you know, we’re seeing animal models where if you over-express genes that make all omega-3s now, those animals develop less colon cancer. If you give animals more omega-6, they’re more likely to develop colon cancers. And it’s not necessarily tied to obesity, right?

So if you look at the plots of body fat, percent omega-6 in body fat since 1960 to today, it’s on a sort of a 45-degree rise, dramatic rise in body fat content of omega-6. Why is that? Well, coincident with that was the big change in the sort of big agriculture producing a lot of soybeans. A lot of soybean oil is cheap. It’s a very inexpensive oil, much less expensive than olive oil, for example. And so that has become a staple for many of the foods, not only in producing them, but also cooking them. So, you know, people fry in them.

Joe

36:08-36:24

Well, you know, Dr. Yeatman, we’re going to take a short break, but when we come back, I want to talk more about soybean oil and even canola oil and a whole bunch of other seed oils and find out, you know, what should we be eating instead?

Terry

36:24-36:51

You’re listening to Dr. Timothy Yeatman. He’s a professor in the Department of Surgery at the University of South Florida. Dr. Yeatman is also Associate Center Director for Translational Science and Innovation at Tampa General Hospital Cancer Institute. His study appeared in Gut, one of the leading journals for gastroenterologists. You’ll find a link to it from the show notes on our website.

Joe

36:51-37:02

It’s time for a short break. You know, I love that example of tortilla chips and guacamole. I’m trying to focus more on the guac than the chips.

Terry

37:02-37:08

Seed oils are thought of as anti-inflammatory foods, but could they be promoting inflammation instead?

Joe

37:08-37:15

We used to be told that avocados and olive oil were problematic because they contained saturated fats.

Terry

37:15-37:23

It seems the medical community has reversed itself on nuts and olive oil. They once were discouraged. Now they’re darlings, what happened?

Joe

37:23-37:31

If we want to avoid high omega-6 seed oils we’ll all have to start reading labels. I wonder what Dr. Yeatman recommends.

Terry

37:39-37:42

You’re listening to The People’s Pharmacy with Joe and Terry Graedon.

Joe

37:51-37:54

Welcome back to The People’s Pharmacy. I’m Joe Graedon.

Terry

37:54-38:13

And I’m Terry Graedon.

Joe

38:14-38:43

Today we’re talking about the safety of seed oils. We’ve long been urged to use cooking oils instead of butter or other fats. At one time, Americans were told that corn or soybean oil were better than olive oil because they’re rich in polyunsaturated fats. The idea was that such fats would lower the risk of heart disease, whereas saturated fat in avocados or olive oil would boost cholesterol and encourage heart attacks.

Terry

38:44-38:56

Now, though, we’ve been learning that excessive reliance on seed oils may increase the chance of developing cancer. In the first part of the show, we heard about research linking these foods to prostate cancer.

Joe

38:57-39:05

Our current guest studies colorectal cancer. His research findings came as a surprise to many nutrition experts.

Terry

39:06-39:24

We’re talking with Dr. Timothy Yeatman. He is a professor in the Department of Surgery at the University of South Florida. Dr. Yeatman is also Associate Center Director for Translational Science and Innovation at Tampa General Hospital Cancer Institute.

Joe

39:26-40:12

So, Dr. Yeatman, you were talking a bit about soybean oil as an omega-6 fatty acid supplier, but there are a lot of others. I mean, you know, people are very big on inexpensive oils to cook with and to make a lot of these ultra-processed foods, whether it’s sunflower or soybean, sesame.

And, you know, we’ve seen some pretty respected nutrition experts who say, oh, they’re anti-inflammatory. They’ll make your cholesterol go down. They’re good for us.

And you’re suggesting, hold your horses. They may be pro-inflammatory and they may cause problems that we didn’t recognize 30 or 40 years ago. Can you dig a little deeper?

Dr. Timothy Yeatman

40:13-41:34

Well, you know, I can give you one example. There is a test you can order through probably LabCorp or Quest. It’s called the PLAC test, PLAC test or PLA2 test. And it’s for phospholipase A2. And I always wondered, why [is] the PLAC test a measure of cardiac inflammation?

And the answer is that it measures an enzyme that releases arachidonic acid from membranes. So here’s a test that’s supposedly measuring cardiac inflammation that’s directly tied to arachidonic acid, which is a derivative of the omega-6s, right? So I think that the inflammation story is, there’s a lot of data on both sides, but it depends on how you look at different data elements and how things are done.

Dietary studies done on humans are often difficult to interpret because it’s hard to measure what diets people actually consumed. I like looking at these genetically induced mouse models where they induce one omega-6 or omega-3, or they feed the mice very controlled diets and look at those results. And you’ll see that there are many studies that show omega-6 is pro-inflammatory. I think that’s [undisputed.]

Joe

41:34-42:28

You know, there was a time not that long ago, Dr. Yeatman, when we were told, don’t use olive oil, don’t use butter. You should be using margarine and all of the seed oils.

And avocado oil was somewhere in the middle, like maybe it’s a problem. And even some of the nut oils were considered a problem.

And now I think a lot of people have done a 180-degree and they say, well, the Mediterranean diet is the best diet and that’s pretty high in olive oil and maybe even a little avocado oil on the side. Help us understand how the medical community has sort of confused people over the years where, you know, don’t eat nuts and don’t use olive oil has just done a flip flop.

Dr. Timothy Yeatman

42:28-44:37

It has, but there are many other examples in medicine where that’s occurred. For example, one of the most prominent ones is postmenopausal hormone replacement therapy for women. It was considered to be a disastrous idea. Now it’s heavily promoted as healthy. So medicine goes through changes with new data.

I can tell you that we now have very sensitive technology, mass spectrometry. And it allows us to pick out specific lipid mediators and really understand what each one is doing. A number of years ago, we didn’t have that. I think some dietary studies are flawed, particularly these ones that try to take dietary histories. But dietary recall is not great for most people. I can’t remember what I had two days ago for lunch. And if you didn’t record in your journal, maybe it wasn’t properly done. So those are all a little bit suspect to begin with.

But overall, I think some of these larger studies now are coming out that, like I said, the UK Biobank. Now there’s one study there that looked at just omega-6. They cherry-picked omega-6 levels and looked at the highest quartile versus the lowest quartile. And sure enough, the highest quartile omega-6 patients seem to have better cardiac outcomes. But they didn’t look at omega-3 in that study.

And another study on the same data set, when they looked at omega-6 and omega-3 ratios, they were predictive of all-cause mortality. So I think it… a lot depends on if you leave data out or if you cherry pick data or just look at subsets of data and don’t look at the whole picture.

I think there’s an emerging consensus that this balancing your omega-6 to omega-3 ratio is probably important, and that probably you can’t do it just by supplementing your way out of it. You probably have to focus on diminishing your omega-6 intake and increasing your omega-3 intake. And the only way to do that is probably to either be uh, um, religiously look at the labels or make your own food.

Terry

44:37-45:07

And making your own food would automatically take care of some of those problems that you pointed out to us several minutes ago, the idea that there’s soybean oil in bread. Well, if you make bread at home, you’re not going to put soybean oil in it. But a lot of people aren’t going to make bread at home. If you make your hummus at home, you’re not going to use soybean oil. Olive oil tastes much better, but a lot of people aren’t going to make their hummus at home. So maybe we all need to start reading labels.

Dr. Timothy Yeatman

45:07-46:10

Well, you know, the other thing is you mention that, but let’s just talk about healthcare costs for a second. You know, the healthcare system we have today, you know, is supposed to be one of the best in the world, but it’s also one of the most expensive. And the reason is we… all of, pretty much all of the CMS codes are directed at therapy, not prevention.

Terry

45:32-45:32

Right.

Dr. Timothy Yeatman

45:33-46:10

And, you know, whenever you want to do something preventative, it’s always a big climb, uphill climb. So I think the whole health system has to change gears towards prevention. Now, if we put the money into prevention that we put into late stage disease because we avoided prevention, we would save a ton of money because late stage disease is cardiac disease and cancer and Alzheimer’s and so forth and diabetes and obesity. If we put money into better food for people, I think we would essentially reduce the health care costs dramatically of the system.

Terry

46:10-46:24

Well, Dr. Yeatman, let me ask you, I have a feeling I can predict your answer here, but let me have you go ahead and answer this question. Is your research relevant for other cancers besides colorectal cancer?

Dr. Timothy Yeatman

46:25-47:28

Oh, absolutely. I don’t think that colon cancer is a unique situation. We have data on other tumors already that shows they’re also inflammatory or inflamed and without resolution of inflammation. Now, I think that there are going to be other diseases where you see sort of an intermediate situation like inflammatory bowel disease or also colitis.

We think there is an intermediate situation there where you see what we call relapsing and remitting disease. And when the patient relapses, they’re probably in an inflammatory stage. When they’re remitting, they’re probably trying as best they can to resolve the inflammation, but ultimately they fail.

Now, are they failing because they have a really bad omega-6 to 3 ratio? I don’t think anybody’s ever looked at that yet, but there are suggestions that your baseline omega-6 to omega-3 ratio might be a good predictor of all cause mortality and outcomes from many diseases.

Joe

47:28-47:49

Now, Dr. Yeatman, your title of the article that you put into Gut about your cancer findings used the word lipidomics. Am I pronouncing that correctly? [guest] 47:44 Yes. [J] 47:45 What is lipidomics and why is it important?

Dr. Timothy Yeatman

47:49-50:12

Well, believe me, it was something that I got into a little bit by chance. When I started working at Tampa General Hospital Cancer Institute and University of South Florida, I was a colon cancer genetics physician scientist. And when I got there, they serendipitously put me into a lab that was next to a lipidomics lab.

Now, lipidomics is the study of lipids. And it can be done in many ways. But lipidomics to some people means HDL and LDL. To me, it means many more things now. So the lipids are really complex molecules that start off with structural lipids, like ceramides and sphingolipids and things like that. And then these things get broken down into active lipid mediators that become signaling molecules.

And what we know today is that the tumor microenvironment, which controls the outcome of the tumor, the immune tumor microenvironment is likely controlled by lipid mediators or the lipids we eat. And I’ll give you a great example. Rectal cancer, I spent 30 years treating rectal cancer patients and doing large operations to remove the rectal tumor, sometimes give the patient a colostomy, many times gives the patient an ileostomy, a second operation to reverse that, chemotherapy, radiotherapy in multiple cycles and series, and ultimately get a cure.

But more recently, they’ve described in a small subset of rectal cancer patients called microsatellite instable patients that they can treat them with checkpoint inhibitors, which activate the local immunity to cure the cancer. So they now have many evidences of cure of these subsets of rectal cancer patients that are cured solely by an injection with a monoclonal antibody that activates the local immune system.

So this, to me, tells me the power of the tumor microenvironment. If that microenvironment can be governed, controlled, regulated, enhanced, that we have the chance to cure more cancers. And lipids may be the key to that.

Joe

50:12-50:55

Dr. Yeatman, I would love to get some practical advice about foods. So my mother loved nuts and she loved macadamia nuts in particular. But I think that her doctors were like, no, no, you shouldn’t be eating so many nuts. And she also loved avocados, and she loved olive oil. And so it seems to me that she was getting a very rich omega-3 based diet.

What kinds of foods do you recommend? Was my mother on the right track? And what are you and your family doing these days?

Dr. Timothy Yeatman

50:52-54:29

Yeah, so she was. And I think this is why the Mediterranean diet has sort of fallen out as the best blue zone diet kind of diet. Yeah, we eat a lot of walnuts. So in the morning, we might have a kale, blueberry, walnut, banana shake, and it’s incredibly good despite the kale being in there. But it gives you a lot of different greens, green vegetable fiber and so forth that helps prevent colon cancer.

By the way, the more greens, different types of greens you get, probably the better because promoting microbiome diversity in your gut. The walnuts are really rich in omega-3s, but you can also use other nuts as well. I don’t know exactly whether macadamia nuts are high or low in omega-3s, but they’re probably okay. Peanuts are not as good, for example, and almonds are good, but for different reasons. Some nuts are good for different reasons. Almonds might be higher in omega-9, for example, of which olive oil is contained. So there’s some [monounsaturated] fatty acids that are really good for you too, but these all haven’t been fully explored yet.

So on the oils, you know, olive oil, avocado oil, you can even use flaxseed oil, all that can be harder to tolerate. And I think chia seeds produce a lot of omega-3s, walnuts, almonds, and on the meat side, you know, grass-fed beef, grass-fed milk, grass-fed butter, lamb is of course, grass fed, chickens that are pasture raised. If you move on to fish, you know, you can eat salmon, low mercury content, haddock higher content. But surprisingly, crabs have one of the highest omega-3 to 6 ratios. They’re like 60 to one in favor of omega-3s, probably because they’re, they’re bottom feeders and eating seaweed and so forth.

So, um, you know, there’s a lot of, and then, then going to the store now, we do look at all the labels. So if the label has more than 10 things in it, unless they’re all spices and natural things, you avoid these long labels, um, because they’re loaded with preservatives and other things that we don’t know, actually don’t know how they affect the gut microbiome. I don’t think it’s ever been tested some of these things. Only recently, we started testing these things because we had technology available to measure the sequencing of the microbiome, uh, with next-gen sequencing. So I know it wasn’t done years ago. So if it’s been done, it’s only done recently.

So again, look at the labels, balance your, try to, and maybe get, the other thing would be try to get your level measured, your omega-6 to 3 level measured. If you can ask your physician to order one of these cardio IQ tests that LabCorp or Quest offer, they’re barely inexpensive and you’ll get an idea of where you are.

No longer can we be happy with LDL and HDL cholesterol. And by the way, most physicians don’t measure lipoprotein(a), which is present in 15% of patients and almost impossible to move all those recent drugs that might do it. But that promotes heart disease and very few people had it measured, yet 15% of the population has it. So there’s a lot of things we can do to prevent disease or to be notified you have disease in advance that’s not being done today.

Joe

54:30-54:38

Dr. Yeatman, are there health implications of inflammatory foods for other conditions besides cancer?

Dr. Timothy Yeatman

54:41-55:30

Yes, certainly we think that other diseases such as diabetes, Alzheimer’s, cardiac disease, stroke, arthritis, inflammatory bowel disease, on and on and on. There are many diseases that likely have a root cause in inflammation. Now, you know, we talk about disease happening over time. Many of these diseases take years to develop.

But in fact, you could imagine a diet impacting your sort of local immunity and inflammation over time, not acutely. So that’s why many of these studies are flawed because they have to look at time series events. You can’t look at yesterday’s diet and say, hey, I had some avocado yesterday, I must be doing well. What did you have the last 10 years to eat?

Joe

55:32-55:57

Dr. Yeatman, your research stimulated an extraordinary amount of interest all around the world. You made headlines in a lot of different places. I’m curious how your colleagues have responded to this fabulous research that you’ve done and the degree of publicity that has emerged as a result.

Dr. Timothy Yeatman

55:59-57:30

Well, surprisingly, maybe not surprisingly, they’re all very excited about it and feel like they’re part of it. As you know, we had a large number of contributors on that paper. There were not only surgeons from Tampa General Hospital, but we had folks at Vanderbilt University, some folks in Japan, folks at Merck, the company Merck, all participated in this fascinating study. But they want to see more. I think what I’ve heard is, well, let’s see more. Don’t stop. Let’s see more.

So that’s where actively, we were recently funded by the NCI with a new U01 grant to study more in depth these lipids. And we’re going to look at close to 400 patients that had colon cancer. And we’ll look at their lipidomics, their lipid mediators in their tumors. But now we’ll be able to relate them to specific genes and mutations of those genes in those same tumors. We were not able to do that before because we didn’t have sequencing and whole genome transcriptomics on these patients.

But now we’ll have all these things, including outcomes. So we’ll be able to answer a lot more questions as to why certain patients have higher levels than others. We can’t relate it to diet in these studies. I think that may be best to be done with animal models where you can control things better. But we can certainly assume that most of these fats are diet-related because that’s the only place they can come from.

Joe

57:30-57:51

And the NCI is the National Cancer Institute, and congratulations on that grant. I wonder if you could just share with our listeners very briefly what they should be avoiding when they go to the supermarket, the grocery store. What are the lipids, the fats that would be best left on the shelf?

Dr. Timothy Yeatman

57:53-01:00:07

Yeah, so it’s pretty easy to figure it out. It’s almost anything you’d like to eat that’s not good for you. So let’s start with the processed donuts, the chocolate covered processed donuts. They’re always sitting out in the aisle. Or anything that’s in a package that has been preserved for a long time. Salad dressing, for example, is loaded with soybean oil. It’s very hard to find a salad dressing without soybean oil in it. Hummus, like I said, you can find occasionally hummus without soybean oil and with olive oil instead.

But all the breads, it is possible to find breads without soybean oil. I was at Ingles one day and I found five different freshly baked breads that didn’t have it. But many of the ones that are processed and sort of preserved longer seem to have this soybean oil. So it’s almost a trend.

You can see if something is likely to stay on your shelf longer, it’s likely more likely to have some of these bad processed products in them. So I think anything that’s in a plastic package that’s going to last more than a week on your table may be suspect. But I would look closely at the label and the number of elements in the label and look for the dyes, look for the “don’t need to be there.” Look for the preservatives that don’t necessarily need to be there and look for the added elements you don’t recognize or understand.

Because again, if you don’t understand what they are, then I can almost guarantee that no one’s tested their effect on the microbiome, which I think is the big barrier. I mean, that’s one thing we didn’t cover in the talk was that the microbiome is the first barrier of defense in almost all of our infections because everything exposed to your nose and mouth is swallowed, goes through the GI tract.

And that’s why you have this incredible immune system there that prevents disease and processes all your food and cleanses it and purifies it. And you have a bunch of immune cells waiting to go in that gut microbiome area. But if they’re turned down or turned off, then things can slip through the defenses.

Joe

01:00:08-01:00:35

Dr. Yeatman, there is one oil that has created an awful lot of confusion and controversy. Canola oil comes from the rapeseed. Is it good? Is it bad? Is it in between? A lot of people thought, ah, canola oil, it’s the answer to our problem of the omega-6 versus omega-3 controversy. What’s your take on canola oil?

Dr. Timothy Yeatman

01:00:35-01:01:23

Well, I think it’s inflammatory. And the problem is that it’s highly processed. If you actually look at the processing conditions for it, it’s heated up, it’s extracted and so forth. People have gone to other ideas like cold pressed, high-oleic, things like that. And I personally don’t know what they all mean yet in terms of is it often better, or worse, or the same. Smoke points are interesting too when these things are heated, they start smoking, they can become oxidized. Sitting things on the shelf for a long time oxidizes them. Some of the things become trans fats. So I don’t think canola oil is a particularly healthy oil to use.

Terry

01:01:23-01:01:28

Dr. Timothy Yeatman, thank you very much for talking with us on The People’s Pharmacy today.

Dr. Timothy Yeatman

01:01:28-01:01:30

You’re very welcome.

Terry

01:01:30-01:01:48

You’ve been listening to Dr. Timothy Yeatman Professor in the Department of Surgery at the University of South Florida. Dr. Yeatman is also Associate Center Director for Translational Science and Innovation at Tampa General Hospital Cancer Institute.

Joe

01:01:48-01:01:59

Earlier, we spoke with Dr. William Aronson. He is Professor in the Department of Urology and Chief of Urology at Olive View UCLA Medical Center.

Terry

01:02:00-01:02:18

We’re talking with Dr. Debora Melo van Lent. She is assistant professor at the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases of the University of Texas in San Antonio. Welcome to the People’s Pharmacy, Dr. Debora Melo van Lent.

Dr. Debora Melo van Lent

01:02:19-01:02:20

Thank you for inviting me.

Joe

01:02:21-01:02:53

Dr. Melo van Lent, we are so fascinated with your research because it’s dealing with something that we care about passionately on the People’s Pharmacy. And that’s what should we be eating and what should we not be eating? There’s so much confusion about food these days, which foods are healthy.

So can you please tell us about your research linking dietary inflammation and dementia? What did you do?

Dr. Debora Melo van Lent

01:02:54-01:04:49

Joe, thank you so much for that question. I so agree with you, because usually we do our research and media so picked little puzzle pieces instead of the whole puzzle. And that is very confusing for the population. So thank you for asking me and for me to give more explanation.

Yes, so I investigated this dietary inflammatory index (Alzheimer’s & Dementia, Jan. 2025). And this index actually is put together with the building stones of our diet. So it contains micronutrients, think about vitamin D, macronutrients, think about protein. And there’s also some bioactive compounds, which you, for example, can find in blueberries.

So the higher this dietary inflammatory index score, the more pro-inflammatory it is. And this is a wonderful index that was created by researchers of the University of South Carolina. And for actually three ways. The first way is because we want to know the building blocks. Because the building blocks are the ones that are either anti-inflammatory or pro-inflammatory. And therefore, we want to concentrate on those. They’re also a way for us to measure existing dietary patterns that we consume during the day. And we can make correlations.

So if we can correlate this dietary inflammatory index with the American diet, for example, we can test how pro-inflammatory that is and to see how we can improve it in speaking about increasing components like single foods that are more anti-inflammatory.

Terry

01:04:50-01:05:01

So you had a lot of participants in Framingham, Massachusetts, that you had information on. What kinds of information did you have on these people?

Dr. Debora Melo van Lent

01:05:03-01:06:15

Yeah, so the Framingham Heart Study is a study that took off in 1948. So we have a very long follow-up of actually already the parents of the participants that were included in my study. So the Framingham Heart Study is a cohort study. So we collect data of people living in a community. So these are not patients in a hospital or a care home, for example, but people like you and me living their lives. And they are giving their time to go to the study center every about four years.

And we are able to collect information on, well, diet is there, but also their cognition. We are able to do MRI scans, PET scans. So we get a very well idea of how the brain is functioning of those participants. But there is so much more that we can collect from them. We collect data on their eyes, their ears, their skin, kidney function, heart function, you name it.

Terry

01:06:16-01:06:30

And Dr. Melo van Lent, people want to know, what did you discover about the relationship between the dietary inflammatory index and people’s risk for dementia?

Dr. Debora Melo van Lent

01:06:31-01:06:59

Yes, of course. So we gathered dietary data through food frequency questionnaires. And that food frequency questionnaire, we were able to calculate the dietary inflammatory index score. So from the participants that we included in our study, we saw that higher pro-inflammatory dietary index scores were associated with an increased risk for incidence, all-cause—and also Alzheimer’s disease—dementia.

Terry

01:07:01-01:07:02

That sounds important.

Joe

01:07:02-01:07:27

That sounds scary because the Western American diet, as we like to refer to it, is rather pro-inflammatory. And so how bad was it if people were eating very inflammatory foods? And we’re going to ask you what some of those foods may be. What happened to their brain?

Dr. Debora Melo van Lent

01:07:28-01:08:23

Yes, indeed. So I actually have another publication that was published a couple of years ago where we looked at approximately like the same study population and their brain (Alzheimer’s & Dementia, Feb. 2023). And yes, we saw that higher pro-inflammatory index scores were associated with smaller total brain volume. So it’s also one component of our health that we cannot control is aging.

So as we age, our brain shrinks slowly. And you want to prevent that. So actually when you’re in your 40s, 30, 40s, you want to actually think about healthy eating because that definitely will work 30 years later when our brain really starts to show aging. And in that sense, as dementia is a disease of aging, you want to prevent it as much as we can.

Terry

01:08:24-01:08:30

Absolutely. And which foods, Dr. Melo van Lent, which foods were most pro-inflammatory?

Dr. Debora Melo van Lent

01:08:31-01:09:46

Yeah, so the Dietary Inflammatory Index score is not actually based on foods. It’s based on the building blocks. So going to the building blocks, so what I mentioned, there were vitamins in there, minerals. So the pro-inflammatory components of the DI that were measured were, for example, cholesterol.

We can measure also like total energy intake, but also saturated fat and total fat, for example. And yeah, so what makes more sense for the public is, for example, saturated fat. And in what kind of foods can we find? Well, we find them, as Joe already just mentioned, the Western diet.

So what are hallmarks of the Western diet? It’s nowadays that we eat these fast foods. We eat, for example, also pastries. And that’s also where saturated fat is embedded in. There’s also ultra processed foods that are full of it. Because what does saturated fat do? It gives flavor. And we love flavor. We want our food just to be lovely to eat.

Terry

01:09:47-01:09:58

Dr. Melo van Lent, what are the implications of your research for a diet that could help us avoid dementia? What should we be eating?

Dr. Debora Melo van Lent

01:10:00-01:13:21

Yeah, so we have the Mediterranean diet. It has been thoroughly investigated across diabetes research, cardiovascular research. So, and then we have the MIND diet, which was established in 2015 by Dr. Martha-Claire Morris of the University of Chicago. So, we are in a nutrition dementia field really playing with the MIND diet, which actually is a hybrid diet between the dietary approach to stop hypertension and the Mediterranean diet. So, we are investigating further the MIND diet. So if we look at components of the MIND diet, what Dr. Morris found is we have the fruits and vegetables, which are in the general guidelines of the American Heart Association, the anti-inflammatory components (Alzheimer’s & Dementia, Sep. 2015).

But particularly for the brain, we are investigating berries. As in berries, they have these anti-inflammatory compounds called flavonols. And they seem to be a great group of anti-inflammatory components that help to reduce systemic inflammation that is happening in our body. And in addition, also green leafy vegetables. So I would say these are the two key newer, more targeted food groups with regard to brain health.

So what we also say is like what is good for the heart is good for your brain. Because like diabetes and cardiovascular disease, they already start earlier in life. So if we can treat those, that will be good for our brain later on. And because we also find like already brain changes and everything happening like in our 40s. So the sooner we target it, the better. So in that sense, what the American Heart Association emphasizes on is also in addition to the vegetables and fruits, to eat whole grains, beans and legumes, to consume more fish. As in fish also has the omega-3 fatty acids, which are unsaturated.

And omega-3 is a big also compound of our diet. That is, yeah, the omega-3 fatty acids play a big role in our brain. And what I also have found in my research, but also poultry and nuts so in that way, and then to preferably limit added sugar. And what is it actually about sugars? Well these crystals, these sugar crystals, already they cause the peaks of our insulin in our body. But in addition, the crystals also damage our veins. And you can imagine like the little veins in our brain are even smaller and tinier and so vulnerable. So in that way, we also for brain research, we advise to be gentle with sugar intake. And in addition, what we already touched upon, the highly processed foods, the refined carbohydrates, saturated fats we talked about. Yeah.

Terry

01:13:23-01:13:29

Dr. Debora Melo van Lent, thank you so much for talking with us on The People’s Pharmacy today.

Dr. Debora Melo van Lent

01:13:30-01:13:31

Thank you for having me.

Terry

01:13:33-01:13:42

Lyn Siegel produced today’s show. Al Wodarski engineered. Dave Graedon edits our interviews. B.J. Leiderman composed our theme music.

Joe

01:13:42-01:13:49

This show is a co-production of North Carolina Public Radio, WUNC, with The People’s Pharmacy.

Joe

01:14:12-01:14:44

Today’s show is number 1,420. You can find it online at peoplespharmacy.com. That’s where you can share your comments about today’s interviews. You can also reach us through email, radio at peoplespharmacy.com. What are you cooking with these days? Corn oil, safflower oil, or avocado oil? Are you reading labels? Highly processed soybean or sunflower oils are common ingredients in seemingly healthy foods like hummus.

Terry

01:14:44-01:15:04

Our interviews are available through your favorite podcast provider. You’ll find the podcast on our website on Monday morning. This week’s podcast also contains an interview with Dr. Debora Melo van Lent about her work on inflammatory foods in the diet and the risk for dementia.

Joe

01:15:04-01:15:22

At peoplespharmacy.com, you can sign up for our free online newsletter to get the latest news about important health stories. When you subscribe, you also have regular access to information about our weekly podcast. You can find out ahead of time what topics we’ll be covering. In Durham, North Carolina, I’m Joe Graedon.

Terry

01:15:22-01:15:54

And I’m Terry Graedon. Thanks for listening. Please join us next week. Thank you for listening to the People’s Pharmacy Podcast. It’s an honor and a pleasure to bring you our award-winning program week in and week out. But producing and distributing this show as a free podcast takes time and costs money.

Joe

01:15:54-01:16:04

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Terry

01:16:04-01:16:09

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Joe

01:16:09-01:16:22

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