The Risk of Alzheimer's Disease

Chris Hemsworth carries two copies of the APOE 4 allele, which puts him at higher risk for Alzheimer's disease. He says he has multiple instances of Parkinson's in his family and every male on his mom's side has died from a cardiovascular event before they age of 60. "With all genetic risk factors, it loads the gun, but it's your lifestyle habits that pull the trigger," Hemsworth says.