Body weight and risk for Dementia are both a confusing and complex topic. One can find reports that state obesity increases the risk for dementia as well as ones that indicate the opposite –that being underweight is the risk factor. And to make things even more confusing, there is evidence that indicates being overweight may protect some people from Dementia.*
It’s needless to say, these unexpected findings are difficult to explain and generate considerable discussion and controversy both in the media and between researchers.
However, what these seemingly conflicting findings show is risk – the factors that influence the likelihood of having Dementia is difficult to assess. A too high body mass index (BMI), uses an equation to calculate a numerical rating of your health based on height and weight, is only one of many known risk factors.
Therefore the big challenge is how to determine the combined effects of having multiple risk factors, such as diabetes, insufficient exercise, and smoking. Does having additional factors make having dementia three times more likely than being overweight alone? Or perhaps the risks compound and put people at 10 times the risk for Dementia?
Is it possible that having a high BMI becomes protective when combined with habits and activities known to reduce risk? As you can see, the number of environmental, behavioral, health-related and genetic influences is huge and the combinations of risk factors are infinite.
Another challenge is separating associative risks from those that cause the outcome. For example, obesity is associated with increased risk for diabetes, but in itself does not cause diabetes. What causes diabetes is the inability of the pancreas to produce sufficient insulin. And, as it turns out, having diabetes is a risk factor associated with having dementia later-in-life.
Therefore, based on what we currently know about BMI and risk for Dementia the best answer is, “it depends.” This means, at this time, the best we can to reduce risk is to make a lifelong commitment to what current clinical research shows are health-promoting habits.
*The Lancet Diabetes and Endocrinology, http://www.thelancet.com/journals/landia/article/PIIS2213-8587(15)00033-9/abstract), Accessed: September 2016.
Contributor: Janet Yagoda Shagam, Ph.D., is a freelance medical and science writer and the author of “An Unintended Journey: A Caregiver's Guide to Dementia.” Available through Amazon.
The opinions expressed by contributing authors are not necessarily the opinions of the Dementia Society, Inc. We do not endorse or guarantee products, comments, suggestions, links, or other forms of the content contained within blog posts that have been provided to us with permission, or otherwise. Dementia Society does not provide medical advice. Please consult your doctor. www.DementiaSociety.org
We don't know exactly. What actually causes dementia is a difficult question. There are an infinite number of factors that singly or in combination may increase risk for, or are associated with having dementia. To add to the mind-boggling complexity, each of us are the outcome of a unique collection of genes, lifestyle behaviors and environmental exposures.
Similar to the word “cancer” the word “dementia” is an umbrella term that includes many kinds of dementia. And again, similar to cancer, the dementias share certain characteristics such as memory loss, but also have ones specific to a particular type of dementia. For example, Alzheimer disease tends to have a slow progression and vascular dementia tends to progress with bursts of increased disability.
In the case of early-onset Alzheimer disease, the answer might be less complicated than it is for other kinds of dementia. Scientists have identified genes that appear to cause the kind of dementia that strikes people younger than 65-years of age. People who have early-onset dementia genes can pass the trait on to their children. However, even these findings open the door to more questions. Do the early-onset genes actually cause the disease or do they increase risk to the extent that makes having early-onset dementia a given. Perhaps the relationship between genetics and this form of dementia involves other genes and factors, that in combination, cause early-onset dementia.
Genetics may or may not play a role in the onset of other kinds of dementia. For example, approximately 15 to 40 percent of people who have frontotemporal lobe degeneration have a family history that includes at least one other relative who also has or had this kind of dementia. However, only 10 percent of these individuals have a form of the disease attributable to specific genes. This means that for 90 percent of cases, scientists have yet to discover genes that increase risk for having Frontotemporal lobe dementia.
Although one cannot change their genetics, it is possible to reduce risk for dementia by modifying certain lifestyle behaviors.
There are many lifestyle behaviors that appear to increase risk for dementia. Some of these include obesity, high blood pressure, smoking, diabetes, and lack of regular exercise. Social isolation, not having meaningful friendships, also appears to increase risk for dementia. Another risk factor is not having the mental stimulation that comes with acquiring new skills and knowledge.
The good news is one can choose to reduce the likelihood of dementia by losing weight, eating a healthy diet, refrain from or stop smoking, exercising, as well as by attending community center activities or taking classes at a local college or university.
Unlike behavioral changes, it’s difficult to impossible to avoid environmental risk factors. While one can make efforts to avoid environmental toxins such as second-hand smoke, it’s not possible to avoid to the fumes that come from car exhaust or from certain kinds of building materials.
Over the past 50 years, there has been a dramatic change in the 10 leading causes for death. Deaths caused by acute infectious diseases and accidents have given way to lingering diseases such as cancer and dementia – both of which tend to occur later-in-life. Therefore, for many people, advanced age is their biggest risk factor for having dementia.
Janet Yagoda
Shagam, PhD, is a freelance medical and science writer and the author of “An
Unintended Journey: A Caregiver's Guide to Dementia.” Available through Amazon.
The opinions
expressed by contributing authors are not necessarily the opinions of the
Dementia Society, Inc. We do not endorse nor guarantee products, comments,
suggestions, links, or other forms of content contained within blog posts- that
have been provided to us with permission, or otherwise. Dementia Society does
not provide medical advice, please consult your doctor. www.DementiaSociety.org
