May 26, 2022
The American Heart Association and American Stroke Association have identified seven steps for maintaining optimal brain health throughout life. The plan, called Life’s Simple 7, can not only prevent heart attacks and strokes, but may also help to maintain memory and ward off or delay the onset of Alzheimer’s disease and other forms of dementia.
Now a new study shows that these seven healthy habits and lifestyle factors may help to lower the risk of dementia in people who carry the APOE-e4 gene, which raises the risk of developing Alzheimer’s disease. The risk is especially high in people who inherit two copies of the gene, one from each parent. The findings reflect a growing body of evidence that what’s good for the heart is good for the brain, even in people at high genetic risk.
“These healthy habits in the Life’s Simple 7 have been linked to a lower risk of dementia overall, but it is uncertain whether the same applies to people with a high genetic risk,” said study author Adrienne Tin, of the University of Mississippi Medical Center in Jackson. “The good news is that even for people who are at the highest genetic risk, living by this same healthier lifestyle are likely to have a lower risk of dementia.”
The seven healthy habits are:
Get regular exercise. Regular physical activity is good for the heart — and the brain. Numerous studies show that staying active helps to maintain brain health, and especially a region of the brain called the hippocampus that is crucial for learning and memory.
Eat a heart-healthy diet. The Mediterranean diet, rich in fruits, vegetables, whole grains, healthy fats like olive oil, and fish, has been shown to be good for the heart and may help to keep the brain in top working order. The DASH diet, also rich in these foods and low in salt, may also provide benefits.
Maintain a healthy weight. Obesity at midlife is a well recognized risk factor for Alzheimer’s disease and other forms of dementia. Strive to keep weight in a healthy range.
Don’t smoke. If you smoke, quit. If you don’t smoke, don’t start. Many studies show that smoking can damage blood vessels throughout the body, including in the brain.
Keep blood pressure in check. Aim for a blood pressure below 120/80. High blood pressure increases the risk of Alzheimer’s and other types of dementia. It can damage blood vessels throughout the body, impairing the flow of oxygen and vital nutrients to the brain and other organs. Narrowing of the blood vessels can also lead to strokes that damage the brain and lead to dementia.
Maintain a healthy cholesterol. Aim for a total cholesterol below 200 milligrams per deciliter (mg/dL) with less than 100 mg/dL of the bad cholesterol (LDL) and at least 40 mg of the good cholesterol (HDL); above 60 mg/dL is ideal. High cholesterol is a known risk factor for Alzheimer’s.
Control blood sugar. A fasting blood glucose below 100 mg/dL is best. Higher levels can predispose to Type 2 diabetes, a risk factor for Alzheimer’s disease.
For the study, published in the journal Neurology, researchers looked at nearly 16,000 adult Americans; about a quarter were African American. They were 54 years old, on average, at the start of the study. The researchers followed them for 30 years.
The researchers ranked them according to how many of the seven habits they adhered to, on a scale of zero to 14. They also assessed their genetic risk, including whether they carried the APOE-e4 gene, which raises Alzheimer’s risk by up to five times when two copies are present. In the study, 28 percent of those with European ancestry carried at least one copy of the high-risk gene, while 40 percent of those with African ancestry did.
Over the 30-year study period, more than 2,200 of the participants developed Alzheimer’s disease or another form of dementia. The researchers found that the more closely people adhered to the seven health habits, the lower their risk of developing dementia, including among those at high genetic risk. For each one-point increase in the lifestyle factors, there was a 9 percent lower risk of developing dementia. The decreased dementia risk ranged from 6 percent to 43 percent, with those of European ancestry showing the greatest decrease in risk.
“In summary, higher Life’s Simple 7 scores, a metric for maintaining cardiovascular and brain health, are largely associated with lower risk of incident dementia across strata of genetic risk,” the authors write. “Late onset dementia is a complex syndrome determined by many health factors, with genetics playing a contributing role. As no effective treatments are available for dementia, modifiable health factors have been gaining increasing attention as potential interventions for the prevention and management of dementia.”
Other studies are ongoing to better understand how heart-healthy strategies can impact brain health over the course of a lifetime. Many factors go into determining who ultimately develops Alzheimer’s disease. Until more effective treatments are found, taking healthy lifestyle steps may help to curb Alzheimer’s onset.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Adrienne Tin, PhD, MS; Jan Bressler, PhD; Jeannette Simino, PhD; et al: “Genetic Risk, Midlife Life’s Simple 7, and Incident Dementia in the Atherosclerosis Risk in Communities Study. Neurology, May 25, 2022