Alzheimer’s Disease Awareness Month: Can it be prevented? Not yet, but lifestyle changes may help reduce risk
The exact cause of Alzheimer’s disease is still unknown and therefore, there is no certain way or no proven strategy to prevent the condition currently. However, experts suggest that a healthy lifestyle may help reduce the risk.
Changes in the brain can occur many years before the first symptoms of Alzheimer’s appear and scientists say that these early brain changes may point to a possible window of opportunity to prevent or delay debilitating memory loss and other symptoms of dementia. Multiple approaches are currently being investigated, but they are yet to identify specific interventions that could prevent or delay the disease.
What can you do?
A healthy diet, physical activity, social engagement, sleep and mentally stimulating pursuits have all been associated with helping people stay healthy as they age. However, Alzheimer’s disease is complex and the best strategy to prevent or delay it may turn out to be a combination of measures. Research suggests that a host of factors beyond genetics may play a role in the development and course of Alzheimer’s.
There is a lot of interest in the relationship between cognitive decline and vascular conditions such as heart disease, stroke, and high blood pressure, as well as metabolic conditions such as diabetes and obesity. Studies currently underway will help determine whether and how reducing risk factors for these conditions may also reduce the risk of Alzheimer’s. Research targets include new drugs to delay the onset or slow disease progression, depression treatment, diabetes treatment, blood pressure and lipid-lowering treatments, social engagement, sleep interventions, vitamins such as B12 plus folic acid supplements and vitamin D, and a combination of mental and physical exercises.
A review, for example, looked at the evidence on ways to prevent or delay Alzheimer’s or age-related cognitive decline. Led by a committee of experts from the National Academies of Sciences, Engineering, and Medicine (NASEM), the authors found “encouraging but inconclusive” evidence for three types of interventions. This includes increased physical activity, blood pressure control for people with high blood pressure and cognitive training.
“Researchers have begun studying combinations of health factors and lifestyle behaviors to learn whether combinations of risk factors better identify Alzheimer’s and dementia risk than individual risk factors. They are also studying whether intervening on multiple risk factors simultaneously is more effective at reducing risk than addressing a single risk factor,” write authors in the 2020 Alzheimer’s disease facts and figures.
In the meantime, experts recommend that people should engage themselves in activities that may keep the brain healthy and the body fit. Clinical trials are testing some of these possibilities.
Blood pressure: Conditions known to increase the risk of cardiovascular diseases such as high blood pressure, diabetes, and high cholesterol, can also increase the risk of developing Alzheimer’s. Some autopsy studies show that as many as 80% of individuals with Alzheimer’s disease also have cardiovascular disease, indicates a report. Scientists are trying to determine whether managing high blood pressure in individuals with hypertension can prevent Alzheimer’s or cognitive decline.
The NASEM committee concluded that managing blood pressure when it is high, particularly for middle-aged adults (ages generally ranging from 35 to 65 years), may help prevent or delay Alzheimer’s.
Physical exercise: Physical activity has many health benefits and some reports have shown that people who exercise have a lower risk of cognitive decline than those who do not. Exercise has also been associated with fewer Alzheimer’s plaques and tangles in the brain and better performance on certain cognitive tests.
“Regular physical exercise may be a beneficial strategy to lower the risk of Alzheimer’s and vascular dementia. Exercise may directly benefit brain cells by increasing blood and oxygen flow in the brain. Because of its known cardiovascular benefits, a medically approved exercise program is a valuable part of any overall wellness plan,” explains the Alzheimer’s Association.
However, while clinical trials suggest that exercise may help delay or slow age-related cognitive decline, there is not enough evidence to conclude that it can slow or prevent Alzheimer’s. An analysis compared high-intensity aerobic exercises, such as walking or running on a treadmill, to low-intensity stretching and balance exercises in 65 volunteers with MCI and prediabetes. After 6 months, authors found that the aerobic group had a better executive function, that is, the ability to plan and organize, as compared to the stretching/balance group, but not better short-term memory.
“Building on the connection between heart health and brain health, researchers have found that factors that protect the heart may also protect the brain and reduce the risk of developing Alzheimer’s or other dementias. Physical activity appears to be one of these factors. Although researchers have studied a wide variety of exercises, they do not yet know which specific types of exercises, what frequency of exercise or what duration of activity may be most effective in reducing risk,” emphasize experts.
Another clinical trial, led by National Institute on Aging or NIA-supported scientists, aims to find out whether exercise may be an effective non-drug treatment for staying cognitively fit. Based on the results, the investigators hope to develop an “evidence-based prescription” that will tell people the type and frequency of exercise needed to support memory and thinking skills.
Diet: The NASEM report did not find enough evidence to recommend a specific diet to prevent cognitive decline or Alzheimer’s. However, certain diets and healthy eating patterns have been associated with cognitive benefits. The Mediterranean diet, which is rich in fruits, vegetables, legumes, whole grains, and fish and uses olive oil as the primary cooking fat, has been associated with a reduced risk of dementia and Alzheimer’s disease. Studies on the same are underway.
Analysis on the Dietary Approaches to Stop Hypertension or DASH diet -- which emphasizes vegetables, fruits, fat-free or low-fat dairy products, whole grains, fish, poultry, beans, seeds, nuts and vegetable oils, and limits sodium, sweets, sugary beverages, and red meats -- is also ongoing.
Staying mentally and socially active: Studies indicate that remaining socially and mentally active throughout life may support brain health and possibly reduce the risk of Alzheimer’s and other dementias. It may help build “cognitive reserve,” but the exact mechanism by which this may occur is unknown. Cognitive reserve refers to the brain’s ability to make flexible and efficient use of cognitive networks (networks of neuron-to-neuron connections) to enable a person to continue to carry out cognitive tasks despite brain changes such as beta-amyloid and tau accumulation. “Experts are not certain about the reason for this association. It may be due to direct mechanisms through which social and mental stimulation strengthen connections between nerve cells in the brain,” explain experts.
(Getty Images)
Interventions such as “brain training” computer games have been shown to improve cognition over a short period, but research has not yet demonstrated whether this can help prevent or delay Alzheimer’s-related cognitive impairment. An analysis of nearly 2,000 cognitively normal adults 70 and older, for example, found that participating in games, crafts, computer use, and social activities for about 4 years was associated with a lower risk of mild cognitive impairment (MCI), a common precursor of Alzheimer’s.
However, reducing the risk of cognitive decline and dementia is not synonymous with preventing cognitive decline and dementia. “Individuals who take measures to reduce risk may still develop dementia, but may be less likely to develop it, or may develop it later in life than they would have if they had not taken steps to reduce their risk. It is also important to note that factors that increase or decrease the risk of cognitive decline and dementia may not necessarily do so by directly affecting the brain changes associated with Alzheimer’s disease,” caution experts.
Education: People with more years of formal education are at lower risk for Alzheimer’s and other dementias than those with fewer years of formal education. Some researchers believe that having more years of education builds cognitive reserve. The number of years of formal education is not the only determinant of cognitive reserve. Having a mentally stimulating job and engaging in other mentally stimulating activities may also help build cognitive reserve.
“It is important to note that the underlying reason for the relationship between formal education and reduced Alzheimer’s risk is unclear. The generally higher socioeconomic status of individuals with more years of formal education may be a protective factor. Having fewer years of formal education is associated with lower socioeconomic status, which may increase one’s likelihood of experiencing poor nutrition, and decrease one’s ability to afford health care or medical treatments, such as treatments for cardiovascular disease risk factors that are so closely linked to brain health,” explains the 2020 report.