Strive to maintain brain health

Based on risk factor statistics, we estimate that there are nearly 10,000 people in the Shreveport-Bossier area (within a 75-mile radius) living with Alzheimer’s disease. While some of what defines how a person ages is determined by genetics, lifestyle choices can greatly impact how we age. Diseases like cardiovascular disease and type 2 diabetes play an important role in aging brain health.

Maintaining a healthy lifestyle, avoiding tobacco, eating well and exercising can help prevent arterial aging. Cardiovascular diseases, including vascular stiffness, atherosclerosis and hypertension, are risk factors for stroke and heart attack, but they also play an important role in Alzheimer’s disease.

One theory of dementia is that cerebrovascular disease reduces the amount of oxygen available to the brain, leading to a mismatch between available oxygen and cellular demand that causes neuronal stress. We are learning now that there is a link between vascular health and the buildup in the brain of plaques and tangles in the brain that are the hallmarks of Alzheimer’s disease.

A large-scale longitudinal study showed that people with a history of either high blood pressure or high cholesterol levels were twice as likely to get Alzheimer’s disease, and those with both were four times as likely. It was also recently reported that 70% of people with dementia also had cerebrovascular disease.

There is some evidence that cholesterol-lowering drugs and antihypertensive medications may lower dementia risk. Cerebrovascular disease may interfere with the normal production and elimination of betaamyloid, the protein that makes up brain plaques. By improving vascular health, it may be possible to slow down the buildup of beta-amyloid. Engaging in physical activity and maintaining quality nutrition can help decrease cholesterol, decrease the risk of hypertension, and help keep balanced beta-amyloid production and elimination.

In addition, improving diet and staying active can help protect us against what scientists call “type 3 diabetes.” Type 3 diabetes occurs when insulin receptors in the brain become desensitized to insulin. Insulin is released when cells need glucose, or fuel. It binds to insulin receptors on the surface of the cell, which results in glucose release. Insulin resistance, which happens when the receptors malfunction, results in abnormal vascular insulin exchange and altered beta-amyloid metabolism.

Hyperinsulinemia, or high blood sugar, may inhibit the degradation of beta-amyloid, resulting in accumulation in the brain and pancreas. Both type 2 and type 3 diabetes and high levels of LDL cholesterol (sometimes called the “bad” cholesterol) have been linked to an increased risk of Alzheimer’s disease.

Many people inquire about the genetic contribution to dementia. While the causes of Alzheimer’s disease and other dementias are not fully understood, there is evidence of a genetic predisposition.

The APOE gene (Apolipoprotein E) is involved in metabolizing fat. It makes proteins that carry cholesterol and other types of fat in the blood. A mutation of this gene, the APOE 4 mutation, is a risk factor for late-onset Alzheimer’s disease. About 25% of people have a copy of this mutation in the general population, while 40-65% of people with Alzheimer’s disease have it.

APOE 4 expression results in deficient beta-amyloid clearance and glucose metabolism. The APOE 4 protein is deposited in plaques along with beta-amyloid.

So why isn’t everyone tested for mutations in the APOE gene? Because knowing your status is not very helpful. Many people with the mutation do not go on to develop dementia, and many people with dementia do not have the mutation.

Also, the only known effective interventions are diet and exercise, which are important independent of mutation status. In fact, the National Institutes of Health only recommends this test as part of medical research.

We all know we should eat better and exercise more, but it can be a daunting prospect. However, making a small change, like drinking water instead of soda and satisfying a sweet tooth with fresh fruit, could significantly impact brain aging. Also, research suggests that exercise is neuroprotective and improves circulation. It also helps with blood sugar and cholesterol.

Adding moderate-intensity aerobic exercise for 20 minutes a few times a week can make a meaningful impact. Regularly going for a walk around the block or taking the stairs instead of the elevator are easy, simple changes that fill the requirement.

There are studies about dementia and brain health going on right in our backyard. LSU Health Shreveport and the Center for Brain Health have several studies on disease mechanisms and on caregiver support programs. If you have any questions or want to learn more about participating in a study, please call and leave us a message at the LSU Health Shreveport Center for Brain Health at (318) 675-4932.

The Center for Brain Health has also recently expanded and is a partner with The Bridge Alzheimer’s & Dementia Center to provide education and support resources. Our new office is located at 851 Olive St. For more information or questions about Alzheimer’s disease and dementia, call 318-656-4800.

Nathan Glassy, research associate, LSU Health Shreveport Center for Brain Health, LSU Health Shreveport Dept. of Neurology; and Elizabeth Disbrow, Ph.D., is director, LSU Health Shreveport Center for Brain Health, and professor, Dept. of Neurology, LSU Health Shreveport.