Obesity may raise risk of Alzheimer's

Preliminary study suggests overweight elderly women more prone to dementia.
22 July 2003

HELEN R. PILCHER

More than 50% of adult Americans and Europeans are overweight. © alamy.com

Women who are overweight at 70 may be at greater risk of developing Alzheimer's disease later in life¹. Prevention and control strategies should stress the benefits of a healthy diet and lifestyle, researchers suggest.

It's a concerning correlation. Dementia and obesity are already major health concerns for the ageing, expanding developed world. By 2025, an estimated 34 million people worldwide will suffer from dementia. More than 50% of adult Americans and Europeans are overweight.

Deborah Gustafson, of Utah State University in Logan, and her colleagues monitored 392 elderly Swedes over 18 years. Of this group, 93 developed dementia. Women who did so in their eighties were more likely to have been overweight in their seventies. "It shows the importance of maintaining a healthy weight throughout life," says Gustafson.

The team measured body-mass index (BMI) - the ratio of weight to height. Normal subjects score between 18.5 and 25. Elderly, demented women had an average BMI of 28, which borders on the obese. Each additional point raised the risk of Alzheimer's disease by 36%, the team found.

Dementia affects 18 million people worldwide, and there is no cure. The chances of succumbing to Alzheimer's disease, the most common form of dementia, rise rapidly with age. Genetics also plays a part - those with an altered version of a key gene are 16 times more likely to develop the disease.

Obesity is one of the few risk factors that you can do something about, says Susanne Sorensen, head of research at the Alzheimer's Society, a charity based in London. "The message is to eat your fruit and veg, take regular exercise and watch your weight," she says.

Dietary factors may play a key role in preventing dementia, agrees Albert Hofman, who studies ageing at Erasmus University's Medical Centre in Rotterdam, the Netherlands. "Some micronutrients may be related to Alzheimer's - a lower intake of vitamin E is linked to a higher risk of the disease," he says. People should eat plenty of foods that provide vitamin E, such as vegetable oils and nuts, he adds.

The Swedish study supports the idea that atherosclerosis, coronary heart disease and diabetes mellitus may contribute to Alzheimer's disease. Obesity raises the risk of developing these vascular disorders, and so may also contribute to the dementia process.

Gustafson's team also monitored their subjects for signs of increased blood pressure and cardiovascular disease. They reckon that they have teased apart these factors, allowing them to focus on obesity alone.

The significant link between large body size and dementia was found only in women as there were far fewer men in the study.

1. Gustafson, D. et al. An 18-Year Follow-Up of Overweight and Risk of Alzheimer's Disease. Archives of Internal Medicine, 163, 1524 - 1524, (2003). |Homepage|