A recent study has found that frequent fluctuations in weight during middle age, especially when the changes are significant, increase the risk of early dementia.
A research team led by Ryu Ji Won from the Inpatient Care Center at Seoul National University Bundang Hospital and Professor Yoon Hyung Jin from the Department of Biomedical Engineering at Seoul National University Hospital announced their findings. They analyzed data from over 3.6 million health screening participants aged 40 to 65 registered with the National Health Insurance Service. The study examined the relationship between repeated weight fluctuations, known as weight cycling, and the occurrence of early dementia.
Sudden changes in weight after middle age can signal health risks. Rapid weight gain or loss is closely linked to various severe illnesses, including cancer, cardiovascular disease, diabetes, weakened immune function, osteoporosis, and cognitive impairments like dementia. Research indicates that greater weight fluctuations correlate with increased mortality rates.
Previous studies focused on one-way weight changes (either increasing or decreasing) to assess the relationship between weight changes and their physical health impacts in middle age. However, this research team analyzed the correlation between the size and frequency of weight cycles (weight loss followed by regain or weight gain followed by loss) and the prevalence of dementia.
The research team tracked patients who underwent at least five health screenings over ten years at 1- to 2-year intervals. They analyzed weight cycling in four categories based on weight fluctuations of more than 3%, 5%, 7%, and 10% compared to their previous weight.
The results showed that patients experiencing weight fluctuations of more than 3% had a 1.2 times higher risk of developing dementia compared to those with fluctuations below 3%. This risk doubled for those with fluctuations exceeding 10%. The average age of onset was 58, which is considered within the early dementia age range.
During the 10-year follow-up period, those who experienced weight cycling of more than 10% twice or more saw their dementia risk increase by up to 2.5 times. The risk was notably higher for those with a body mass index (BMI) of 25 or more than those with a lower BMI.
These findings suggest that frequent and significant weight cycling, such as yo-yo dieting or rapid weight loss following significant weight gain, negatively impacts brain health and increases the likelihood of early dementia onset.
Ryu commented, “This study raises awareness about weight management. Excessive weight fluctuations can cause metabolic stress and negatively affect the body, so individuals over middle age must maintain a stable weight within a healthy range.”
