- Alzheimer’s disease is becoming more common as life expectancy is increasing and the baby boomer generation is aging
- Alzheimer’s disease is caused by the death and dysfunction of brain cells
- There are several risk factors for Alzheimer’s disease such as age, genetics, gender, etc.
- Mild cognitive impairment, an intermediate stage between normal age-related memory problems and dementia, is also considered a risk factor for developing Alzheimer’s
- There is no cure for Alzheimer’s but living a healthy and active lifestyle can reduce the risk of developing Alzheimer’s disease
The United States is experiencing a “graying” of the population, with the Baby Boomer generation, born post-WWII between 1946 and 1964, reaching older age in large numbers. This significant demographic change is also happening worldwide. For the first time in history, older adults (ages 65 and older) will soon outnumber young children (ages 5 and younger).
In addition, people are living longer. Since the likelihood of developing Alzheimer’s disease increases drastically with age, it is projected that there will be a growing number of individuals living with AD. It is specifically estimated that the number of older Americans living with Alzheimer’s disease, currently at 5.2 million, will almost triple by 2050, reaching 13.8 million.
Fortunately, research in this area is exploding as well. In 2011, President Obama signed the National Alzheimer’s Project Act, with the goal of preventing and treating Alzheimer’s Disease by 2025. Alzheimer’s disease is the most common cause of dementia- a group of brain disorders characterized by a decline in mental ability.
Alzheimer’s and other forms of dementia are difficult diseases that can take a huge toll on individuals diagnosed and their loved ones. And it’s important to recognize that dementia also takes a huge toll on our healthcare system, and it is growing costlier by the day. For these reasons, research attempting to understand risk factors and causes of Alzheimer’s Disease, as well as to discover strategies and medications for prevention, has become an important priority in the scientific community. Research takes time however, and we don’t have clear answers yet. Below is what we know so far.
Like other types of dementia, Alzheimer’s disease is caused by the death and dysfunction of brain cells. Since dementia is a progressive disease, this cell death gradually spreads throughout the brain and parts of the brain shrink or atrophy, particularly those involved with memory and other mental functions. By the final stage of Alzheimer’s, the brain damage is widespread, and brain tissue has shrunk significantly. Researchers still do not know exactly what causes this brain cell death, but it is believed that plaques and tangles play an important role. Amyloid plaques consist of the abnormal buildup of a protein known as beta-amyloid between nerve cells in the brain. This buildup can erode the connections between brain cells. Tangles, made up of another protein called tau, gradually destroy the network system that is necessary to supply essential nutrients throughout the brain. It is likely that damage to the brain starts to occur about 10 years before memory and other symptoms of cognitive impairment become evident.
There are several factors that seem to put individuals at greater risk of developing Alzheimer’s Disease. Some of these factors are within our control, although unfortunately others are not.
The strongest risk factor for developing Alzheimer’s disease is age. As we get older, our chances of getting Alzheimer’s increase. According to the National Institute on Aging, after the age of 65, our risk of developing Alzheimer’s disease doubles every five years. Individuals at the highest risk are those who are over 85, among whom 1 in 3 are estimated to have Alzheimer’s disease. This is important because individuals who are 85 and older are one of the fastest growing groups in our population.
The role of genes in the development of Alzheimer’s disease is not fully understood, but researchers have discovered some genes that seem to play a part. The gene with the greatest known effect on Alzheimer’s Disease is apolipoprotein E, called APoE. All people are born with two copies of the APoE gene.
There are three forms of APoE: e2, e3, and e4. E2 is the rarest form, which seems to be linked to a reduced likelihood of developing Alzheimer’s. E3 is the most common and does not seem to influence the risk of Alzheimer’s. However, APoE4 is the greatest genetic risk factor that we know of, and it is estimated to play a role in 20-25% of Alzheimer’s cases. Though having one or two copies of ApoE4 does not guarantee you will develop Alzheimer’s disease, it does increase your risk.
It is also possible to inherit genes that directly cause Alzheimer’s, but that are much more rare, affecting less than 5% of the population. They are seen in those with familial Alzheimer’s, a very rare form of the disease that usually results in early-onset Alzheimer’s, affecting individuals before age 65. If a person has this gene, then each of their children has a 50% chance of inheriting it and developing dementia. Familial genes involved in Alzheimer’s disease include: PS1(presenilin-1), PS2 (presenilin-2), APP (amyloid precursor protein).
Individuals with Down Syndrome are born with an extra copy of chromosome 21, which carries the APP gene, which in turn is why individuals with Down Syndrome are more likely to develop Alzheimer’s, and may develop it at an earlier age.
Women are more likely than men to develop Alzheimer’s disease, and the reason why is not fully understood. Part of the reason may be that women live longer than men, but research shows this gender difference exists even after accounting for this difference in life expectancy. Recent research has started to examine whether genetic or hormonal differences might play a role in these patterns.
Interestingly, this gender difference is not the case for other types of dementia, for which women and men tend to be at equal risk. One exception seems to be vascular dementia, for which men seem to be at higher risk. This is because men are more prone to stroke and heart disease, which can lead to vascular dementia.
Another risk factor for developing Alzheimer’s Disease is having a low level of education. Individuals with less than a high school education are much more likely to develop Alzheimer’s, whereas those with a college education are much less likely to get the disease. More specifically, if you have 7 or fewer years of education, your risk of developing Alzheimer’s at any age is two-fold higher than the risk of someone who has over 10 years of education. These differences may be due to a variety of reasons, as higher education is often associated with other determinants of good health, including better jobs, higher income, and less toxic environmental exposure.
Mild cognitive impairment is an intermediate stage between normal age-related memory problems and dementia. MCI is characterized by problems in memory, thinking, language, and judgment that are more serious than the normal changes that occur with aging. Unlike with dementia however, these changes are not severe enough to interfere significantly with daily life. Having MCI is considered a risk factor for developing Alzheimer’s and other forms of dementia, but not everyone with MCI goes on to develop dementia. Some stabilize or even see a reversal and improvement in their memory. Some factors, such as anxiety level, may influence whether individuals with MCI progress to Alzheimer’s disease.
Hypertension, high cholesterol, diabetes, obesity, and stroke are all risk factors for developing Alzheimer’s Disease and other forms of dementia. Conditions that put you at risk for cardiovascular disease basically also put you at risk for experiencing cognitive decline. More on this in the next section on prevention.
The word “prevention” may be a little misleading. As of now, there is no “get out of jail free card,” no one prescribed activity you can do or pill you can take that will ensure you don’t develop Alzheimer’s disease. However, research suggests several lifestyle changes you can make that seem to reduce the risk of developing Alzheimer’s:
Stay engaged – “Use it or lose it”
The more we stimulate our brains, the more we build up what some researchers have termed “cognitive reserve.” Research has shown that some people exhibit few symptoms of Alzheimer’s disease, despite having the markers of the disease in the brain. Some believe this pattern can be explained by the concept of cognitive reserve, which is, in essence, the buildup of compensatory resources in the brain that seem to emerge from staying sharp and mentally engaged throughout life. For these reasons, people who work in mentally challenging or complex occupations seem to be less likely to develop Alzheimer’s.
While you may not be able to change your occupation, there are many ways you can keep your mind active and challenged on a regular basis. For example, you can learn new things (such as a new language), participate in book clubs or workshops, or do activities as simple as crossword puzzles and reading the newspaper. The earlier we start building this cognitive reserve, the better, but it’s also better late than never. No matter how old you are, a greater level of participation in leisure activities (physical, social, and intellectual) seems to have a positive effect on your brain.
Occasional stress is a normal part of life. However, chronic stress, which is when we are highly stressed for prolonged periods of time, can be taxing on our physical and mental health. In fact, high levels of cortisol, the hormone elevated during stress, can damage the brain cells in the hippocampus, that part of the brain most associated with memory. Researchers have also found that people who have neurotic personalities may also be more likely to develop the disease. Therefore, targeting and reducing stress with therapy, exercise, and/or meditation and mindfulness techniques may be beneficial to minimize stress and, in turn, reduce one’s likelihood of memory impairment.
We are all familiar with the age-old saying, “You are what you eat.” It’s true that diet affects so many aspects of our lives, from our physical health and appearances to our energy levels and our moods. What many may not realize, however, is that our diet is also related to our cognitive functioning. Just like the rest of our body, brains require a rich supply of vitamins and nutrients. The right foods can boost our mental energy and improve our ability to concentrate.
The Mediterranean diet has long been viewed as one of the healthiest ways of eating, and evidence suggests that its benefits extend to our brain as well. The Mediterranean diet is rich in fruits, vegetables, legumes, whole grains, and olive oil. It also contains moderate amounts of fish and lean poultry. While you will want to limit your red meat intake, you can drink moderate amounts of red wine. The diet is associated with lower risk of heart disease and several forms of cancer, as well as increased longevity. In addition to the noted health benefits, research also suggests that greater adherence to the Mediterranean diet is related to reduced risk of developing Alzheimer’s.
On the opposite end of the spectrum, obesity is related to worse cognitive performance. Individuals with type 2 Diabetes have a 50% chance of developing Alzheimer’s, which is a significantly higher probability than the rest of the population. This connection may be because of increased inflammation, which researchers think may be tied to both metabolic diseases (such as Diabetes) and Alzheimer’s disease. The Mediterranean diet may help reduce this dangerous inflammation in the body.
What type of mental stimulation should be practiced to slow the progression of Alzheimer’s disease and Dementia?
Exercise has many widespread health benefits, one of which seems to be a reduction in the likelihood of developing Alzheimer’s, and potentially slowing the progression of the disease. In contrast, living a sedentary lifestyle, characterized by a lot of sitting and inactivity, makes people more prone to cognitive decline.
Experts suggest that regular physical activity (several times per week, for 30-60 minutes) can help preserve thinking, reasoning, and learning abilities in healthy adults. Studies also suggest it can improve mental functioning in people with mild Alzheimer’s disease or mild cognitive impairment, and delay the start or slow the progression of Alzheimer’s disease in those at risk of developing it. Exercise also improves our mood and sleep and can reduce stress and anxiety. Exercise also targets other aforementioned risk factors, reducing the risk of heart disease and diabetes.
We know smoking is dangerous for our health, but when we think about the health ramifications, lung cancer is usually the main disease that comes to mind. However, research suggests that older adults who smoke are also at a greater risk for dementia and cognitive decline. Smoking heavily in midlife also seems to be related to greater risk of developing Alzheimer’s and vascular dementia.
The research on alcohol is a little less clear. Some evidence suggests that moderate consumption of alcohol may have a beneficial or protective influence on our brains, whereas heavy alcohol consumption or alcoholism tends to be detrimental. The type of alcohol also seems to be important, with most research pointing to the health benefits of regular and moderate consumption of red wine.
Protect your head
Certain types of head injuries may increase your risk of developing Alzheimer’s later in life. As early as 2 hours after a traumatic brain injury, there is a surge of amyloid production in the brain. Less significant head injuries can be dangerous as well. For example, one study found that soccer players who frequently head the ball show greater cognitive impairment.
For these reasons, you can reduce your risk of cognitive decline by refraining from playing aggressive contact sports like football, wearing a seatbelt, wearing a helmet when biking, and taking other precautions to protect your head.
Limit air pollution exposure
Air pollution particles from power plants and automobiles may increase the chance of developing Alzheimer’s disease. Various studies have supported a connection between exposure to high levels of air pollution and faster rates of cognitive decline as well as a greater chance of developing dementia, including Alzheimer’s disease. One study found that people living in neighborhoods with worse air quality scored lower on memory tests than those living in cleaner areas. Therefore, the detrimental effects of air pollution on our brains may be evident even before we reach older age. For those who already have a high genetic disposition towards Alzheimer’s, air pollution may pose an even greater risk.
Greater levels of social support and larger social networks are generally related to better health outcomes. Studies suggest that those with more and higher quality social relationships have a decreased risk of experiencing a variety of health problems, including stroke and heart disease. It turns out they are also less likely to see declines in cognitive functioning and to be at risk for dementia. One of the mechanisms behind this association seems to be that social support and social relationships help us cope with stress, which as mentioned before, is physically and mentally taxing.
In contrast, loneliness, social isolation, and depression tend to have negative effects on our health. Studies suggest that individuals who feel alone are more likely to develop dementia. Interestingly, it seems to be more about individuals’ perceptions of whether they felt lonely than if they were alone. Those who are socially isolated but don’t feel lonely, for example, do not seem to be at higher risk of developing the disease.
As of now, we do not fully understand what causes Alzheimer’s disease, nor do we currently have a cure or drug that prevents dementia. Based on what we know from research thus far however, living a healthy and active lifestyle seems to be the most effective thing we can do to lower our odds of developing Alzheimer’s. Thus, the saying “healthy body, healthy mind” seems to ring true.
Since there is currently no cure or preventative treatment, we also need to focus on care. There are some drugs on the market that slow or alleviate symptoms for a limited period of time, but they are not effective for everyone. While researchers continue to work on developing a cure or an effective means of prevention, it is equally important that we continue to focus on supporting dignity and quality of life in people living with Alzheimer’s disease or other types of dementia. There are many ways we can help support people with dementia and cultivate positive feelings and meaningful interactions, even in the later stages of the disease. Whether they are loved ones living at home or patients in a health care setting, caregivers can help make them comfortable and content.
Just because there is no cure or treatment for Alzheimer’s does not mean there should not be effective care, and we need to strive to provide care in the most supportive, positive, and person-centered manner possible.