While we were researching BMI for women, we ran across a study that looked at whether a high BMI can shrink your brain and cause dementia.
A little background first… BMI stands for body mass index. It’s an indirect way to calculate your total body fat based on your current height and weight.
It’s not a perfect measure. It can be especially inaccurate for athletes and older people who are frail. But for most others, BMI may indicate whether your weight is healthy or putting you at risk for disease.
Of course, you have to discuss this with your doctor before drawing any conclusions about your weight and your BMI.
We’ve already talked about the link between dementia and weight before. In case you missed it, you might want to take a look at our post, “Got A Big Belly? The Good News and The Bad News…”
Basically, that study said that a big belly in mid-life increases your risk of dementia in later years… whether you’re overweight or not.
The scientists weren’t sure why. But a big belly is already linked to a greater risk of diabetes, stroke and heart disease. So maybe these diseases cause the greater risk of dementia associated with a high BMI. No one really knows yet.
The newer BMI research from Dr. Sudha Seshadri of the Boston University Alzheimer’s Disease Center expands on these earlier studies.
Dr. Seshadri and her colleagues looked at 733 participants of the ongoing Framington Heart Study. They had an average age of 60 with about 30% men and 70% women.
The medical team wanted to see if total brain volume was associated with BMI, belly fat, waist-to-hip ratio and waist circumference.
What they found was a bit surprising.
A higher BMI for women and for men was linked to lower brain volumes in older and middle-aged adults. Higher BMI, smaller brain.
But the researchers found the strongest link between abdominal fat and brain size. More belly fat, smaller brain. And this brain-belly fat link held no matter what a person’s BMI was.
So it seems that belly fat is a stronger indicator of dementia than BMI. (Prior studies have found that people with smaller brains have a higher risk of dementia.)
We can’t help you with measuring your belly fat; the doctors used CT scans for that.
But if you want to track your BMI, take a look at our BMI calculator which you can use online. It’s for adults who are at least 20 years old.
But remember, no one really knows if a high BMI for women or for men is the cause of a smaller brain.