Gene that's usually bad news loses its punch if you live to your 90s, study finds

A gene linked to the risk of developing Alzheimer's, heart disease and diabetes becomes less important to quality of life once people hit their 90s, a Mayo Clinic study shows. At that point, good friends and a positive attitude have a bigger impact, the researchers say. The findings are published this month in the Journal of American Medical Directors Association.

Researchers used the National Institutes of Health-supported Rochester Epidemiology Project, a database of patient records in Olmsted County, Minn., to find people ages 90 to 99 living on their own or in long-term care. The 121 participants completed an interview, a physical exam and a quality-of-life questionnaire. Participants were divided into groups based on their cognitive function, to sort out the effects of age and disease on well-being, and blood samples were taken for genotyping.

Researchers discovered that those who carried the gene in question, known as ApoE4, were no worse off than others in the study.

"We found if people had good physical, intellectual, and emotional well-being, more social connectedness, and if they perceived themselves to have better coping skills, they felt they had better quality of life," says co-author Maria Lapid, M.D., a Mayo Clinic psychiatrist.

"The study shows that the ApoE4 genotype doesn't determine what your quality of life will be, and that, regardless of your gender, environmental factors play a significant role in your physical, emotional, spiritual, and social well-being," she says. "You can have good quality of life regardless of this gene."

The median age of those studied was 93; 87 percent were women. Those reporting poorer quality of life tended to be men, for reasons that are unclear, and people who experienced pain.