Healthy Brains, Hearts and Bodies
Learning how to age healthfully
Healthy brain aging is a topic of growing interest as baby boomers hit retirement age. 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. But diseases like dementia, cardiovascular disease and type 2 diabetes are not part of normal aging. While some of what defines how a person ages is determined by genetics, lifestyle choices can have a big impact on how we age. Healthy aging might just be a skill that can be learned.
Maintaining a healthy lifestyle, avoiding tobacco, eating well and exercising can help prevent arterial aging. Cardiovascular disease, 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. What we are learning now is that there is a link between vascular health and the buildup of plaques and tangles in the brain that are the hallmarks of Alzheimer’s disease. A largescale 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, and there is some evidence that cholesterol-lowering drugs and anti-hypertensive medications may lower dementia risk. Cerebrovascular disease may interfere with the normal production and elimination of beta amyloid, the protein that makes up brain plaques. By improving vascular health, it may be possible to slow down buildup of beta amyloid. Engaging in physical activity and maintaining quality nutrition can help decrease cholesterol, decrease the risk of hypertension, and help maintain balanced beta amyloid production and elimination.
In addition, improving diet and staying active can help protect us against what scientists are calling “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 ask me 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 (Apolipopotein 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. In the general population, about 25% of people have a copy of this mutation, 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 a drug study.
We all know we should eat better and exercise more, but it can be a daunting prospect. But making a small change, like drinking water instead of soda and satisfying your sweet tooth with fresh fruit could have a big impact on 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. Practicing balancing exercises can help prevent the risk of falling and also increase lower body strength. Now that we are all stuck inside, I have been looking at YouTube fitness videos that show short workouts of different intensities that can be done right in the living room.
There are studies going on about curing dementia right in our back yard. If you would like 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. It might take us a few days to call you back because of the COVID-19 outbreak, but we are eager to answer questions and discuss our ground-breaking work so we will call you back! If you are interested in learning more about dementia and caregiving, a good resource is the Alzheimer’s and Dementia Resource Center at alzagency.org. They have great information about resources for families dealing with dementia in the Shreveport Bossier area.
Nathan Glassey is pursuing his PhD at the School of Graduate Studies at LSU Health Shreveport and works the Disbrow Lab, and Elizabeth Disbrow, PhD, is an associate professor in neurology and dwwirector of the Center for Brain Health at LSU Health Shreveport.