Well-functioning lungs reduce risk of dementia

May 17 2006

A middle-aged woman with well-functioning lungs runs less risk of developing Alzheimer's disease.

A new study carried out at the Sahlgrenska Academy in Goteborg, Sweden, shows a strong statistical correlation between lung capacity and dementia.

The findings are presented in the coming issue of the prestigious American journal Neurobiology of Aging.The study is based on the so-called Survey of Women in Goteborg, a population study that has been under way since 1968.

The study covers a total of 1,291 women. These women's lung capacity was first monitored in 1974 and then in 1980 when the women were in middle age. The monitoring was the repeated several times up to 2000. Of these women, 147 had developed dementia, 96 of them in the form of Alzheimer's disease.

The study shows that there is a clear statistical correlation between the functioning of their lungs and their risk of developing Alzheimer's disease.

"Our theory is that poor lung function leads to the brain receiving less oxygen, and this in turn increases the risk of dementia," says Xinxin Guo, a post-doctoral fellow at the Sahlgrenska Academy.

The better the lung function the women in the study had in middle age, the lower their risk of later developing Alzheimer's disease. For each 20% of better lung capacity, the risk of acquiring Alzheimer's declined by one quarter.

Dementia brings great suffering to its victims and their friends and relatives, and this health problem represents a huge cost to society. Some 200,000 Swedes have some form of dementia.

"This study underscores the importance of maintaining well-functioning lungs. If you exercise regularly and refrain from smoking, you can influence the risk of your contracting Alzheimer's," says Professor Ingmar Skoog.

Age and genetic heredity are the most important factors in the risk of developing dementia. Previous research has indicated that vascular disease and obesity increase the risk of dementia disorders, but this is the first report about a tie to the functioning of the lungs.