Does body fat affect your risk of developing dementia or Parkinson’s disease?

People with high levels of fat stored in the belly or arms may be more likely to develop diseases such as Alzheimer’s and Parkinson’s. than people with low levels of fat in these areas, according to a study published in the July 24, 2024, online edition of Neurology®, the medical journal of the American Academy of Neurology. The study also found that people with high levels of muscle strength were less likely to develop these diseases than people with low muscle strength.

“These neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, affect more than 60 million people worldwide, and this number is expected to increase as the population ages, so it is critical to identify ways to modify risk factors to develop some preventive tools,” said study author Huang Song, MD, PhD, of Sichuan University in Chengdu, China. “This study highlights the possibility of reducing the risk of developing these diseases by improving body composition. “Interventions aimed at reducing fat in the trunk and arms while promoting healthy muscle development may be more effective in protecting against these diseases than overall weight control.”

The study involved 412,691 people with an average age of 56 who were followed for an average of nine years. At the start of the study, body composition measurements such as waist and hip measurements, grip strength, bone density, and fat and muscle mass were taken.

During the study, 8,224 people developed neurodegenerative diseases, mainly Alzheimer’s disease, other forms of dementia and Parkinson’s disease.

In male participants with high levels of belly fat, neurodegenerative diseases developed at a rate of 3.38 per 1,000 person-years, compared with 1.82 cases per 1,000 person-years in participants with low levels of belly fat. For women, the rate was 2.55 for high levels and 1.39 for low levels. Person-years represent both the number of people in the study and the amount of time each person spends in it.

After adjusting for other factors that can affect disease rates, such as high blood pressure, smoking and drinking alcohol, and diabetes, the researchers found that overall, people with high levels of abdominal fat were 13% more likely to develop obesity and these diseases than people with low levels of abdominal fat.

• People with high levels of arm fat were 18% more likely to develop these diseases than people with low levels of arm fat.
• People with high levels of muscle strength were 26% less likely to develop the disease than people with low levels of strength.
• The association between these body compositions and neurodegenerative diseases was partly explained by the emergence of cardiovascular diseases such as heart disease and stroke after the study began.

“This highlights the importance of timely control of these cardiovascular diseases to help prevent or delay the development of Alzheimer’s, Parkinson’s or other degenerative diseases,” Song said.

One limitation of the study is that the participants were mostly white people from the United Kingdom of Great Britain and Northern Ireland, so the results may not be applicable to other populations.

The research was supported by Sichuan University, Sichuan Provincial Department of Science and Technology and the Swedish Research Council.

LINK

Associations between body composition, cardiovascular disease and risk of neurodegenerative diseases in the UK Biobank