"Which factors increase the chance of aging with well–maintained functions?" Older men who never smoked, avoided obesity and had held a healthy Mediterranean–inspired diet have good chances of maintaining their independence at a very high age.

These findings were shown in a study conducted at the Department of Public Health and Caring Sciences at Uppsala University and recently published in the Journal of American Geriatrics Society.

The study started in 1970, when all men in Uppsala County, born 1920 to 1924, were invited to participate and 2,322 men (82%) participated in the first investigation of the Uppsala Longitudinal Study of Adult Men (ULSAM). The aim was to investigate the relationship between aging with preserved independence and lifestyle factors, including dietary patterns and cardiovascular risk factors.

The participants have so far been followed up on six occasions. At the age of approximately 71, 1,104 of the men answered a questionnaire about lifestyle including education, living conditions and physical activity. Adherence to a Mediterranean–like diet was assessed according to a modified Mediterranean Diet Score derived from a seven–day food record, and blood pressure and other cardiovascular risk factors were measured.

Sixteen years later, 369 participants, with a mean age of 87, were eligible for evaluation of ‘independent aging’. This was defined as high cognitive function in terms of testing and lack of dementia diagnosis, not institutionalized, and being independent in personal daily activities including being able to walk outdoors on their own.

"Previous studies have shown that very old subjects appraise a preserved function higher than absence of disease," says Kristin Franzon, who is a geriatrician and a PhD student at the Department of Public Health and Caring Sciences.

At the age of 85, 57 % of the men were alive and 75 % of the 369 participants at a mean age of 87 displayed independent aging. Men who never smoked doubled the chance of achieving this independency compared to smokers. Independent aging was also associated with normal weight or overweight (BMI <30 kg/m^2) and a waist circumference <=102 cm, as well as high adherence to a Mediterranean–like diet. Similar observations were observed with survival.

"As far as we know, this is the only study so far done in men, which shows an association between high adherence to a Mediterranean–like diet and independent aging," said Kristin Franzon.

The Mediterranean–like diet consists of high intake of polyunsaturated fatty acids, fish, fruits, vegetables, cereals and potatoes and less meat and dairy products.