[Click! Health] Rapid Weight Fluctuations... Increase Dementia Risk in Middle Age

A study has found that when middle-aged adults experience repeated cycles of weight gain and loss with large fluctuations, their risk of early-onset dementia increases.

This study was conducted by the research team led by Professor Jiwon Ryu from the Hospitalist Center at Seoul National University Bundang Hospital and Professor Hyeongjin Yoon from the Department of Biomedical Engineering at Seoul National University Hospital. They analyzed data from over 3.6 million health screening participants aged 40 to under 65 registered in the National Health Insurance Service database in South Korea.

The research team investigated the relationship between so-called ‘weight cycling,’ where weight repeatedly rises and falls, and the occurrence of early dementia. Sudden weight changes after middle age can be considered a 'health warning.' Rapid weight gain or loss is closely linked to various severe diseases such as cancer, cardiovascular disease, diabetes, weakened immunity, osteoporosis, and cognitive impairments including dementia. It is also known that greater weight fluctuations correlate with increased mortality rates.

Until now, studies on weight changes after middle age and their physical adverse effects have typically analyzed unidirectional changes, either increases or decreases. However, the research team conducted a study analyzing the association between the magnitude and frequency of weight cycles?where weight goes up then down or vice versa?and dementia prevalence.

Using data from patients who underwent health screenings at least five times at intervals of 1 to 2 years and were followed for 10 years, the team categorized weight cycle fluctuations into four groups based on changes compared to previous weight: ▲3% or more ▲5% or more ▲7% or more ▲10% or more. The results showed that patients experiencing weight cycles with fluctuations of 3% or more had a 1.2 times higher risk of developing dementia compared to the normal group with less than 3% fluctuation. Notably, when fluctuations were 10% or more, the risk sharply increased up to twice as high. The average age of onset was 58, which falls into the early dementia age range.

Furthermore, during the 10-year follow-up period, patients who experienced weight cycles with fluctuations of 10% or more two or more times had their dementia risk increase up to 2.5 times. It was also confirmed that the risk associated with weight fluctuations was higher in individuals with a BMI of 25 or above compared to those with lower BMI.

The researchers interpreted these findings to suggest that large and frequent weight cycles?such as yo-yo effects where weight falls then rises or weight gain followed by rapid loss?negatively impact brain health and may increase the incidence of early dementia.

Professor Jiwon Ryu stated, “This study highlights the importance of awareness regarding weight management. Excessive weight fluctuations can cause metabolic stress and other adverse effects on the body, so for middle-aged and older adults, it is necessary to focus on maintaining a stable weight within an appropriate range.”

The study results were published in the international academic journal Alzheimer’s Research & Therapy.