Healthy Aging

Conditions and diseases such as vascular disease, high blood pressure, heart disease, and type 2 diabetes may increase the risk of Alzheimer’s and cognitive decline. Observational studies have been the primary source of information about the links between these conditions and Alzheimer’s. Past studies revealed that high cholesterol and obesity during midlife have also been linked to increased risk of Alzheimer’s disease. High blood pressure and diabetes have been linked to Alzheimer’s as well. Studies have shown that abnormal insulin production (insulin is the hormone involved in diabetes) contributes to Alzheimer’s-related brain changes.

Many studies are looking at whether preventing or controlling these diseases and conditions through medication, diet, and exercise can reduce the risk for Alzheimer’s. The results are mixed. One large clinical trial, funded by the National Institutes of Health (NIH), compared intensive blood sugar lowering medicines with standard treatment in nearly 3,000 older adults with diabetes. After 3 years there was no significant difference in memory function between the two groups. Another clinical trial is testing insulin nasal spray in older adults with mild cognitive impairment (MCI) or mild to moderate Alzheimer’s to see if it can improve memory and daily functioning.

Additional studies and clinical trials are looking at aspirin, medications used to treat high blood pressure and other heart conditions, and the diabetes drugs Metformin and Pioglitazone. One NIH clinical trial is looking at how lowering blood pressure to or below current recommended levels may affect cognitive decline and the development of MCI and Alzheimer’s disease.

Observational studies have linked social engagement (for example through work, volunteering, or living with someone) and mentally stimulating activities (for example reading, going to lectures, and playing games) with lowering the risk of Alzheimer’s disease.

One large study of healthy older people found a relationship between more frequent social activity and better thinking, understanding, learning, and remembering. It is not clear whether improved cognition resulted from the social interaction itself or from related factors that generally accompany social interaction, such as increased intellectual stimulation.

Another large observational study looked at the impact of ordinary activities like listening to the radio, reading newspapers, playing puzzle games, and visiting museums. After 4 years, the risk of developing Alzheimer’s disease was on average 47 percent lower for those who did the activities most often than for those who did them less frequently.

Formal memory training also seems to have cognitive benefits. For example, in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial, healthy adults 65 and older participated in 10 sessions of memory training, reasoning training, or processing-speed training. The sessions improved participants’ mental skills in the area in which they were trained. These improvements persisted 10 years after the training was complete.

Additional studies examine the combination of formal cognitive training and exercise while other studies are examine different types of formal cognitive training, such as learning digital photography, quilting, and volunteering at local schools.

The reasons for the apparent link between social engagement or intellectual stimulation and Alzheimer’s risk aren’t entirely clear. Scientists theorize that these activities may protect the brain by establishing “cognitive reserve,” which allows the brain to operate effectively even when it is damaged or some brain function is disrupted. These activities may help the brain become more adaptable in some mental functions so it can compensate for declines in other functions. Scientists also suggest that people who engage in these activities may have other lifestyle factors that protect them against Alzheimer’s disease. One theory is that less engagement with other people or in intellectually stimulating activities could be the result of very early effects of Alzheimer’s rather than its cause.

Information courtesy of the National Institutes on Aging

Read the National Institutes of Aging article on Advanced Cognitive Training

Observational and intervention studies have suggested that physical exercise may be a factor in decreasing the risk for Alzheimer’s disease and normal memory loss due to aging.
Research with animals helps us understand how exercise protects the brain. Studies with older rats and mice show that exercise increases the number of small blood vessels that supply blood to the brain as well as the number of connections between nerve cells. It also raises the level of an important brain protein that is important to memory and learning.

Research with humans has also demonstrated that physical activity increases the number of connections between brains cells as well as maintains the old connections. These new connections are vital to healthy cognition, which includes awareness, perception, reasoning, and judgment. In a year-long study, 65 and older people were divided into two groups. The first group exercised daily doing an aerobic program of walking for 40 minutes. The second group did a nonaerobic program of stretching and toning exercises. After the study finished, the aerobic walking group showed improved connectivity in the part of the brain that impacts daydreaming, envisioning the future, and recalling the past. This group also improved on planning, organizing, strategizing, paying attention to and remembering details.

More research trials are ongoing to help determine the impact of exercise on fighting off Alzheimer’s.

Researchers are examining whether a healthy diet can help preserve memory or reduce the risk of Alzheimer’s.

A number of studies found that a diet rich in vegetables, especially green leafy vegetables and cruciferous vegetables like broccoli, is associated with a reduced rate of decline in reasoning and understanding. One epidemiological study reported that people who ate a “Mediterranean diet” decreased their risk of developing mild cognitive impairment (MCI) by 28% and decreased their risk of progressing from MCI to Alzheimer’s disease by 48%. The main aspects of this diet include proportionally high consumption of olive oil, legumes, unrefined cereals, fruits, and vegetables; also moderate to high consumption of fish, moderate consumption of dairy products (mostly as cheese and yogurt), moderate wine consumption, and low consumption of meat.
Studies have found that food high in saturated fats and refined carbohydrates (for example white sugar) could hurt memory function. In one study, scientists fed rats food that was high in fats and simple carbohydrates for 3 months. The rats fed the high fat “Western Diet” performed significantly worse on certain memory tests than rats fed a diet containing one-third the fat.

Diet studies have also examined DHA (docosahexaenoic acid), an omega-3 fatty acid found in salmon and a few other fish. These studies looked at mice that were bred to have beta-amyloid proteins which are the key feature of Alzheimer’s. The studies found that DHA reduces beta-amyloid plaques, abnormal protein deposits in the brain that are a hallmark of Alzheimer’s. Even though clinical trial studying DHA in humans showed no impact on people with mild to moderate Alzheimer’s disease, it is possible that DHA supplements could be effective if started much earlier before memory symptoms appear.

Forgetfulness can be a normal part of aging; however, aging does not result in an inevitable loss of cognitive abilities. As people age, both the body and the brain change. Often it takes longer to perform a task, learn new things, and it is more difficult to multi task. Scientists have found that given enough time, older adults do as well on complex memory or learning tests as younger people. In fact, as they age, healthy adults usually improve in areas of mental ability such as vocabulary. While certain areas of thinking do show a normal decline as we age, others remain stable.

Read more about the Signs of Normal Aging

Some memory problems are related to treatable conditions – medication side effects, vitamin B12 deficiency, chronic alcoholism, tumors or infections in the brain, or blood clots in the brain. Some thyroid, kidney, or liver disorders also can lead to memory loss.

Emotional problems, such as stress, anxiety, or depression, can make a person more forgetful and can be mistaken for dementia. Dealing with major life changes such as death or retirement leaves some people confused or forgetful.

Information courtesy of the National Institutes on Aging

Read the National Institutes of Aging’s article on Forgetfulness