A weighty issue… A spare tyre around the middle is not all bad!

The young and middle aged should aim to be slim and sylph like, but for older men, at least a little bit of lard is not such a bad thing.

A team of researchers at the University of Western Australia and Royal Perth Hospital studied over 12,000 Perth men selected at random from the electoral roll. All were between the ages of 65 and 84 and had no symptoms of dementia.

They then looked at the relationship between three measures of obesity – body mass index (BMI), waist measurement and waist to hip ratio – and age, marital status, education, alcohol use, smoking, diet, physical exercise and existing heart and circulator conditions on the development of dementia.

They found that overweight – but not obese – older men had a lower incidence of dementia than either their slimmer or fatter colleagues.

“We are struggling to explain the results,” said Leon Flicker, Professor of Geriatric Medicine and one of the study authors. “Being overweight after 70 doesn’t have the same negative effects that it does in younger men.

“Overweight men aged 40-50 have an increased risk of dementia. At some point there is a cross over period so that older people are less at risk.

“Men over 70 and in reasonably health good health but overweight are less likely to develop dementia. Exactly why we don’t know.

“We can speculate that fat tissue may have some important protective role in older men or it may build some resilience into the system.”

Other lifestyle features that lowered the incidence of dementia included being married, having a better education, moderate alcohol consumption, taking exercise and use of low fat milk.

“We controlled for smoking in our model. Current smokers had a small increase of around 12 percent in hazard of developing dementia. Most other studies have shown a larger effects of the order of 30 to 40 percent.”

Men with pre-existing diabetes, high cholesterol and heart disease also had higher incidence of dementia.

The researchers found a J shaped curve relating obesity and risk of dementia. The lowest point was older men with a BMI of 25-30, waist measurement of 100cm and waist to hip ratio of one.

One possible explanation is that men who were overweight in mid-life might have died of other diseases before reaching old age so that the survivors were unusually healthy compared to the normal weight counterparts. On the other hand overweight men who survive longer have a greater opportunity to be diagnosed with dementia, which is exactly the opposite of what the team found.

The incidence of dementia at around ten percent of the aged population was similar to that found in other studies.

Although only men participated in the study the results almost certainly apply equally to women, said Professor Flicker.

Participants had lower mortality than those who were invited and chose not to participate in the trial and than those who were not invited to take part.

The next study is looking at what happens if people lose weight. Does the risk of getting dementia increase?

“If you are over 70, overweight and in good health there is no reason to diet unless you have diabetes or arthritis,” said Professor Flicker.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.