When considering health risk factors, we can distinguish between “non-modifiable” risk factors such as genetics, and “modifiable” risk factors. Researchers are keen to understand the link between modifiable risk factors and different health concerns, especially health concerns that can become a burden on society. Obesity seems to be a risk factor associated with various complications such as cardiovascular disease, stroke, diabetes, and even dementia. Discussing weight is always a sensitive issue, but studies show that maintaining a target weight is about health and quality of life, and not merely about appearances. The good news is that weight is a modifiable factor, that means it can change!

There are several reasons why obesity might contribute to dementia, some studies link excess body fat with brain volume deficits which are an early marker of neurodegeneration. But other studies suggest that obesity can be helpful in preventing dementia, this is known as the “obesity paradox”. Researchers recognized the need to provide clear evidence for the link between obesity and the development of dementia so they conducted a study over about 18 years. Their findings were published in the International Journal of Epidemiology in June of 2020, and the evidence is clear that that individuals who are overweight or obese are at higher risk of developing dementia.

The study was done on voluntary participants, both men and women, who were about 50 years old and dementia-free at the beginning of the study. Researchers recorded various factors, such as hypertension, diabetes, marital status, and others, but focused on Body Mass Index (BMI), Waist Circumference (WC), and various cognitive tests to assess dementia. The participants were interviewed every two years, and their nurses every four years.

The researchers made one sample group based on BMI and one based on WC. The BMI sample showed that participants who had a normal BMI were less likely to develop dementia. In the WC group, they found that a higher WC indicated a 39% increased risk of dementia but only in women, a higher WC in men did not seem to have any relation with dementia. This goes to show that abdominal fat has different effects in men than it does in women and that men and women need to approach healthy weight management in different ways.

The data from the WC sample was very interesting because they were able to analyze the it under various categories: normal BMI with normal WC, normal BMI with high WC, obese BMI with normal WC, and obese BMI with high WC. Not surprisingly, they found that being obese with a high WC was associated with a 1.28-fold increase in dementia risk particularly in women. The increased risk was present even after controlling for hypertension and diabetes. Another key piece of information that this study provided was that obesity was more of a dementia risk factor in older participants.

The information gathered from this study can be used by public health officials to help plan for and prevent dementia. But more importantly it provides even more incentive to maintain healthy weight. This study also shows that different bodies respond to things differently, that means that you should consult your doctor about your weight and not rely on fad diets and exercises. Your doctor will help you determine what is the best plan for you.