Diabetes Freedom
You probably know that obesity is linked to many illnesses, including diabetes, heart disease, and some forms of cancer. But did you know that there is evidence for an association between excess body weight and cognitive impairment, including memory problems?
Obesity and cognitive aging
As we get older, our cognitive abilities, such as memory and ability to make decisions, decline. This change is normal, and is known as “cognitive aging.” However, some people are more severely affected than others.
Research into aging has revealed that many factors affect how quickly your brain ages and some scientists believe obesity is among them. In one study with older adults, overweight and obese adults underperformed on recall tasks compared to normal-weight participants. Other research with middle-aged and older adults has found that normal-weight individuals fare better than their overweight and obese peers on vocabulary tests.
A 2018 review of 14 studies concluded that obesity can worsen memory function. The authors found that four of the 14 studies in the review didn’t find any direct relationship between weight and memory, but their overall verdict was that obesity is likely to have a negative effect on cognitive ability.
Obesity and brain atrophy
What could explain these findings? One possibility is that excess body fat is linked to gray matter atrophy in the brain. Being very overweight or obese (adiposity) appears to cause some areas of the brain to shrink, especially in middle and old age.
According to a paper published in the journal Ageing Research Reviews, several studies have shown a positive correlation between adiposity and a loss of gray matter in areas of the brain that are important for memory, including the frontal lobe.
In 2016, a team of researchers at the University of Alabama conducted an experiment with mice to investigate the effects of weight gain on memory. They overfed mice until they were obese and tested the animals’ spatial memory regularly over a 23-week period.
After 23 weeks, the mice showed significant memory impairment. As the mice became larger, several genes normally responsible for helping the neurons in their brains to create new memories stopped working properly. Although this experiment has not been replicated in humans, the results suggest that weight gain could have a serious and relatively fast effect on cognitive function.
The importance of maintaining a healthy weight
Weight is only one factor in cognitive aging, and we still don’t fully understand the connection between adiposity and memory. But there is enough evidence to suggest that keeping your weight within healthy limits could help your brain age well.
Most healthcare professionals recommend keeping your Body Mass Index (BMI) between 19 and 25 and maintaining it with a sustainable, balanced diet and exercise regimen. If you need help deciding on a target weight or changing your habits, start by asking your doctor for tailored advice. Avoid extreme or fad diets that limit or eliminate entire food groups, because they are unlikely to provide you with all the nutrients you need for good health.