Being Apple-Shaped and the Risk of Dementia

We know that being apple-shaped is more of a health risk than is being pear-shaped. Body fat that is centralized to the abdomen (being apple-shaped) is a strong risk factor for diabetes, heart disease, stroke, and death from all causes, just by itself. This remains true even when the individual in question has a normal Body Mass Index. Further, that abdominal fatness, as one symptom of the metabolic syndrome (a collection of five symptoms), has been linked to an increased risk of Alzheimer's (Bite, 01/10/07).

Researchers with Kaiser Permanente of Northern California wondered, If being apple-shaped over the long term is by itself such a strong risk for diabetes and heart disease, would being apple-shaped also be a strong risk for dementia? (Neurology; e-Pub ahead of print at www.neurology.org)

To find out, the researchers identified current members of Kaiser Permanente (a nonprofit group medical practice) who had been continuous members since between 1964 and 1973 and were between 40 and 45 years of age at that time. In that 9-year period all of the eligible patients were those whose blood pressure and cholesterol levels, height, weight, waist measurement, and thigh circumference measurement were taken as part of their routine medical care.

In 2006, the endpoint of the study, this meant a group of eligible patients of over 6500 men and women were still alive and still members of Kaiser Permanente, although they were now between 73 and 87 years of age. Over 1000 of the 6500 men and women had been diagnosed with dementia between 1994 and 2006. Their waist and thigh measurements were compared with those who were not diagnosed with dementia.

The waist measurements of all patients were grouped into five levels, beginning with normal waist circumference for the individual's Body Mass Index. Comparatively, those at the highest waist circumference saw their risk of demential increase by almost 300 percent! Even when the researchers adjusted for Body Mass Index across the board, the highest levels of waist circumference meant that an individual's risk of dementia was still increased by almost 200%.

By contrast, those whose Body Mass Index was in the overweight or obese ranges, but who were pear-shaped, had their risk of dementia only increase by 80%.

What this means for you

This doesn't mean that being pear-shaped protects you from the long term consequences of obesity; it just means that your risks are not as high as those whose body fat is carried mainly in their belly. If you are apple-shaped, make an effort to reduce your risks by being of normal weight, following a healthy diet, and getting regular exercise.

First posted: April 9, 2008