By: The HumanN Editorial Team
Our HumanN experts weigh in on a controversial study about the influence obesity has over your brain function.
Amen, D. G., Wu, J., George, N., & Newberg, A. (2020). Patterns of Regional Cerebral Blood Flow as a Function of Obesity in Adults. Journal of Alzheimer’s disease : JAD, 10.3233/JAD-200655.
The Findings: A connection between obesity and blood supply to the brain.
Dr. John P. Cooke, MD, PhD
This recent article in the Journal of Alzheimer’s Disease suggests that obesity reduces blood flow to the brain. This conclusion is based on a large data set of 35,000 brain imaging studies in 17,000 people. The brain imaging that was done measures blood flow to the brain, during rest and during a mental activity. The reduction in blood flow to the brain with obesity is important, because intellectual activity requires blood flow. Furthermore, there is evidence that reduced blood flow to the brain can be associated with Alzheimer’s disease in the long run.
I think that these findings are very interesting, but they do raise the question as to how obesity can affect brain blood flow. In fact, I believe that we know the answer to that question. Many previous studies have revealed that obesity is associated with abnormal blood levels of sugar and fat. In addition, there are adverse alterations in the blood level of hormones such as insulin. Also, obesity is associated with high blood pressure. Each of these factors is known to impair the ability of blood vessels to relax, because they impair the function of the endothelium. The endothelium is the lining of the blood vessel, and it secretes beneficial factors, such as nitric oxide, to open up the vessels and increase blood flow. It is known that obesity, high blood pressure, high blood fat and sugar levels, each impair the function of the endothelium. So it is likely that the impaired blood flow to the brain in people that are overweight, is related to an impairment of endothelial function. What is the solution? Maintain a healthy weight; consume foods that enhance endothelial function (I favor a Mediterranean diet); consider the use of nutritional supplements that have anti-oxidant effects and/or increase the levels of nitric oxide in your blood; get daily exercise (a brisk walk for 30 minutes a day is sufficient); stop smoking; drink no more than 1-2 servings of alcohol daily; and exercise your brain! Puzzles, good conversation, hobbies, learning a new skill, reading a good book; all of these increase blood flow to the brain, and done regularly, can maintain and enhance your cognitive ability.
Dr. Lynn Roper, Registered Pharmacist, PhD
We know obesity is a controllable risk factor related to dementias such as Alzheimer’s Disease and Vascular Dementia–which can result in the hardening and narrowing of blood vessels. We also know obesity affects heart function (cardio metabolic function), can increase blood pressure, and is related to high cholesterol. It can also raise blood sugar (diabetes). All of these effects can result in decreased blood flow to the brain. We also know obesity can cause the body to be somewhat of an inflamed state, and inflammation in the brain can be related to dementias. So this study’s outcome is in line with what we already know.
I’m impressed at the size of this study but surprised that most of the subjects they chose had psychological conditions (some more than one). The subjects’ other psychological conditions and their medications could have played a role in decreasing blood flow. The study would have been even better to choose subjects without other conditions and daily medications to eliminate variables.
Dr. Ivy, PhD
This research study is a major breakthrough demonstrating that the brain responds to how the body is treated. We have known for decades that abusing our bodies by overeating and maintaining a sedentary lifestyle results in various forms of metabolic disorders such as cardiovascular disease, type II diabetes, hypertension and cancer, and reduces life expectancy.
Now, we have evidence that such a lifestyle will result in a reduced brain circulation with the consequences being the development of Alzheimer’s disease or some other abnormal mental condition such as depression and bipolar disorder. This study significantly reinforces the need for individuals to develop a healthy lifestyle with a proper nutrition and physical activity plan being the cornerstone.