Obesity: A Risk Factor for Dementia
Obesity is associated with a higher risk of developing dementia up to 15 years later, according to a new study by the UCL Institute of Epidemiology & Health Care. The good news is that there’s also evidence that weight management could play a substantial role in reducing the risk of developing Alzheimer’s disease, Lewy Body dementia, and other losses of cognitive function.
The Connection Between BMI, Belly Fat, and Dementia
Research published in the International Journal of Epidemiology suggests middle-aged people who are obese have an increased risk of developing dementia by as much as 31% compared to those whose body mass index (BMI) is within the healthy range. However, it’s not just about BMI—research has also shown that central obesity (excess belly fat) is a contributing risk factor.
BMI, which is one of the most common ways to measure obesity, is based on the relationship between a person’s height and weight. A BMI of 18.5 to 25 is considered healthy; greater than 25 is overweight and greater than 30 is considered obese. However, BMI doesn’t measure body fat or take into account muscle mass—which could put someone who has high muscle mass in the obese range even if they’re healthy.
A better indication of obesity is a person’s waist-to-hip ratio (WHR). Overall, belly fat was found to be a better predictive factor in dementia than BMI alone. Women who had a WHR greater than 0.85 and men with a WHR greater than 0.90 are considered centrally obese. In addition, people who have a healthy BMI but are centrally obese have approximately twice the risk of developing dementia than people who have a high WHR.
In addition, excess belly fat in otherwise healthy middle-aged adults correlated with having smaller brain volumes. This suggests there may be a link between belly fat and brain shrinkage, which may be a contributing factor to the risk of developing dementia later in life. Belly fat is harmful to the brain because it contributes to increased inflammation, insulin resistance, and the risk of developing diabetes.
Gender also plays a role in the risk of dementia. Women with excess body fat had a 39% increased risk of dementia compared to those who had a healthy level of abdominal fat—however, an increased risk wasn’t found among male participants.
Furthermore, the study found that the link between obesity and dementia was independent of other risk factors, such as smoking, hypertension, diabetes, or a genetic predisposition for dementia.
Prevention Through Lifestyle is Key
The results of this research stress the importance of maintaining a healthy weight, particularly later in life. The benefits also extend beyond dementia prevention; obesity is associated with a number of serious diseases and health conditions, including type 2 diabetes, heart disease, high blood pressure, stroke, and some cancers. Fortunately, the risk of developing dementia and other serious health concerns can be mitigated or avoided completely by maintaining a healthy lifestyle through diet and exercise.
If you’re currently in the overweight or obese BMI range, or you have a low WHR, taking steps now to lose weight can have significant benefits for your health. If you’re not sure where to start or would like support on your weight loss journey, you may want to consider a medical weight loss program. Dr. Jennifer Hubert is a board-certified physician specializing in internal medicine and medical weight loss. She takes a holistic approach, focusing on the prevention and improvement of a wide range of adult diseases through nutritional counseling, medical monitoring, and behavior modification. To schedule a consultation, contact Dr. Hubert’s office today at 707-575-THIN (8446).
