As seen in Psychology Today.
Dementia is, unfortunately, a very common phenomenon among the elderly. As of 2017, there were as many as 44 million individuals worldwide living with dementia. In the United States, as many as one in three seniors has some form of dementia when they pass away.
More than just being a mental health issue, dementia can be extremely taxing on the family and friends of the individuals who are struggling with the condition. It is far more severe than merely telling the same story that everyone has heard before. As the condition progresses, individuals with dementia lose their ability to live independently because they find it too difficult to conduct the activities of daily living—from doing household chores down to feeding, dressing, and grooming themselves—and this can oftentimes lead to frustration and aggression. In the later stages of dementia, individuals may not recognize family and they may come to seem like completely different people. As they exhibit increasingly dysfunctional behavior, it may even make it too difficult for family members to continue to offer care.
Dementia is not a disease itself, but rather a series of conditions that can arise when an individual is afflicted with one or more of the over 60 diseases that can cause dementia—most of which are quite rare. In approximately 60% of dementia cases, the underlying ailment is Alzheimer’s disease. In approximately 30% of dementia cases, it is either Lewy body dementia or vascular dementia. Of the remaining 10% of dementia cases, the underlying condition could be one of the following: Frontotemporal dementia, corticobasal degeneration, depression-related dementia, alcohol-related dementia (typically manifesting as Korsakoff’s syndrome), Creutzfeld-Jacob disease, Huntington’s disease, normal pressure hydrocephalus, or certain forms of Parkinson’s disease and some related conditions. It is often the case that diseases co-exist, most frequently with Alzheimer’s disease and vascular dementia. When this happens, it is known as mixed dementia.
In most cases, genetics plays a dominant role in determining if an individual will develop dementia, and researchers have been relatively fatalistic about the prognosis of the condition. In other words, there has been a longstanding belief that dementia is inevitable for certain individuals with genetic predispositions, and that environmental factors, such as lifestyle and diet, do not play a major role in determining the course of the diseases that can give rise to dementia (with the obvious exception of alcohol-related dementia or dementia that arises from head injury, stroke, or a disease like meningitis). This is particularly true with forms of dementia that occur earlier in life, such as frontotemporal disorders or Huntington’s disease.
New research, however, indicates that the environmental components behind some common diseases that give rise to dementia have a greater impact than previously thought. This is true for the three most common diseases that cause dementia: Alzheimer’s disease, Lewy body dementia, and vascular dementia.
A New Hope
A new study from the University of Exeter that spanned eight years and analyzed the data of 196,383 adults of European ancestry over the age of 60 is challenging the belief that one’s genetics solely influences whether one develops dementia. The study found that participants who had both a high genetic risk and an unhealthy lifestyle were three times more likely to develop dementia than those who had a low genetic risk and a healthy lifestyle. This should not come as a tremendous surprise. What was shocking was that the study also found that the risk of dementia was 32% lower in participants who had a high genetic risk if they maintained a healthy lifestyle when compared with the group who had a less favorable lifestyle.
This should not be taken to mean that the risk can be entirely eliminated for those with genetic predispositions for dementia. Nor should one assume that diet is as important as genetics when assessing the risk for dementia, as there are numerous causes for dementia with their own pathologies. The aforementioned study that was published on JAMA’s site earlier this month shows that, statistically speaking, the risk of developing dementia can be mitigated to some degree with a healthier lifestyle.
The study’s authors presented their findings at the Alzheimer’s Association International Conference 2019 in Los Angeles, where they described the differences between healthy and unhealthy lifestyles. No surprise, the research indicates that smoking; drinking more than a moderate amount of alcohol; having a diet high in fat, sugar, and salt; and not exercising regularly are all behaviors to avoid.
Why This Is a Big Deal
While the Exeter study is not alone in its findings, it is far more comprehensive and concrete than earlier studies. Even a recent meta-analysis published in 2017 that found that strict adherence to the Mediterranean diet (which includes physical activity and sharing meals with family and friends that are high in fruits, vegetables, whole grains, and healthy fats; less high in fish, poultry, beans, and eggs; moderate in dairy and red wine; and low in red meat and prepared or processed foods) was associated with reduced risk in cognitive decline. The analysis examined nine cohort studies involving only 34,168 participants in total. There were six times that number of participants in the Exeter study. Furthermore, the analysis only examined diet.
Other studies have been deemed less conclusive because of more substantial limitations. For example, a 2017 study found a correlation between artificial sweeteners and dementia (as well as stroke). According to the study, “Drinking at least one artificially sweetened beverage daily was associated with almost three times the risk of developing stroke or dementia compared to those who drank artificially sweetened beverages less than once a week.”
As strong as this conclusion may sound, the study suffers from some weaknesses. There are a variety of factors that were never accounted for, and, consequently, could be affecting the study’s results. Perhaps most important of all, it did not look at artificial sweeteners in general—only in soft drinks. Consequently, the study cannot be certain about the amount of artificial sweeteners consumed by any of the study’s participants, as the Mayo Clinic notes many processed foods, including some baked goods, candy, puddings, canned foods, jams, jellies, and dairy product, may contain these compounds.
Similarly, not every disease that gives rise to dementia will be affected by improving one’s diet; it remains a condition with a significant genetic component. However, for the majority of diseases that can cause dementia, it seems that there is now stronger evidence than ever that making lifestyle changes, such as quitting smoking, reducing the amount of alcohol one consumes, exercising more, and eating better, can have a major impact on the progression of the condition. There is also overwhelming evidence that these same changes can improve overall mental health, and many physicians have come to recommending them when treating conditions like depression, anxiety, and other mood disorders.
Furthermore, genetic research and testing have shown promise in identifying genes with a strong link to dementia, and research and technology are constantly improving our ability to produce better and more targeted testing that can pinpoint and predict predispositions to dementia at earlier stages in life. This allows individuals with a higher risk for dementia to learn about the specific risks associated with their genetics and to make modifications to their lifestyle and diet earlier in life, which can affect not only how one feels today, but how one feels later in life.
Dr. Ahmad reports no conflict of interest. He is not a speaker, advisor, or consultant and has no financial or commercial relationship with any biopharmaceutical entity whose product/device may have been mentioned in this article.