Can You Be Too Thin?
Posted 6/22/2017 by UHBlog
Does extra body weight boost brain power? Maybe.
A recent study published by the Lancet Diabetes and Endocrinology Journal suggests that being too thin can increase a person’s risk for dementia. Researchers found that people with a BMI (body mass index) below 20 in their 40s, 50s and 60s were 34 percent more likely to be diagnosed with dementia up to 15 years later, compared with people of a healthy weight.
Does this mean you should add French fries, ice cream sundaes and triple cheeseburgers to your diet?
Not so fast, says geriatric medicine specialist William Schwab, MD, PhD, AGSF.
“This is an observational study, so it shows correlation, not causation,” he says. “There may be other factors in play or explanations that researchers must consider before they can make positive conclusions about body weight causing dementia.”
According to Dr. Schwab, an important factor researchers should consider is the life expectancy of someone who is seriously overweight at midlife.
“The surest way not to develop dementia is to die before it happens because the primary risk factor in developing dementia is advanced age,” he says. “The odds of developing dementia increase exponentially with each five-year period past the age of 65. One out of three people will have clinically significant dementia at age 85, and these numbers increase with each passing year.”
Another factor to consider when suggesting that being overweight or obese in middle age appears to protect brain health is that the same metabolic abnormalities that keep people underweight at midlife may also contribute to dementia risk.
“The good news is we have changed a healthy BMI from the low 20s to the high 20s in regard to life expectancy,” Dr. Schwab says. “We also no longer advise seniors in their 70s, 80s and 90s to lose weight, since weight loss in older people lowers their life expectancy.”
If a little extra weight in senior years can be protective, is there a diet that people can follow to lower their risk for dementia?
“I am not aware of any strong evidence that a diet exists that can lower or prevent a person’s risk of developing dementia,” he says. “I wouldn’t discourage a healthy diet, but I can’t say that it does or doesn’t affect dementia risk.”
What Dr. Schwab does recommend – “without making promises,” he says – is regular exercise and a sensible diet to improve your heart, lung, gut and brain function.
Also, leisure time activities that boost cognitive ability can do no harm.
“I’ve never seen anyone experience a brain sprain doing a crossword puzzle or playing bridge,” says Dr. Schwab. “There is no doubt that being active socially and physically can improve a senior’s quality of life, but whether these activities prevent dementia remains to be seen.”
To determine a person’s extent and type of memory loss, University Hospitals Foley ElderHealth Center provides comprehensive, multidisciplinary evaluation of seniors with physical, psychological and social problems, with a strong emphasis on cognitive function and specific ability to carry out the activities of daily living.
William Schwab, MD, PhD, AGSF, is a geriatric medicine specialist and Medical Director of House Calls at University Hospitals Cleveland Medical Center. You can request an appointment with a geriatric medicine specialist or any other doctor online.