Dementia is a growing problem. According to the “Delphi Consensus Study,” published in Lancet (2005; 366(9503): 2112-7), there is a new case of dementia every seven seconds. The authors predicted that the number of cases of dementia would double in developed countries between 2001 and 2040. There were an estimated 23.4 million cases of dementia worldwide, with 4.6 million new cases each year.
Diet may, in part, help reduce the risk. Research published in Archives of Neurology (Dec 2006; 63: 1709–17) found that greater adherence to the Mediterranean diet was linked with a lower incidence of Alzheimer’s disease. The researchers analyzed the diets of 194 Alzheimer’s patients and 1,790 people without the disease. Subjects were rated on their adherence to the Mediterranean diet using a 0-to-9 scale and a 61-item food frequency questionnaire. Each point increase in dietary adherence was associated with a 19% to 24% lower risk. Those in the top third of compliance had a 68% lower risk compared with those least likely to follow the diet. This type of eating pattern is rich in plant foods and naturally provides many of the protective compounds discussed in our articles on [diet] and [antioxidants].
Obesity also appears to increase the risk of dementia. In research published in the British Medical Journal (2005; 330(7504): 1360), investigators followed 10,276 men and women over a 27-year period. Subjects who were obese at the time of the initial evaluation had a 74% greater chance of developing dementia than those of normal weight. This is one more reason to look at dementia as part of a bigger metabolic picture rather than as an isolated brain disorder.
Exercise may also help protect the aging brain. Research published in The Journals of Gerontology Series A: Biological Sciences and Medical Sciences (63:529-535 (2008) examined physical activity in 2,263 men aged 71 to 92 who did not have dementia at the start of the study. During an average follow-up of 6.1 years, there were 173 new cases of dementia. The incidence was lower with increasing levels of physical activity and better physical function. Among men with low physical function, high levels of physical activity were associated with about half the risk of dementia compared with those who were least active. The authors concluded that increasing general physical activity in elderly men with poor physical function may help delay the onset of dementia.
Like so many chronic health problems, dementia does not appear out of nowhere. It is influenced by the same lifestyle factors that affect metabolism, circulation, and inflammation throughout the body. A poor diet, excess weight, and inactivity may all contribute to processes such as [brain inflammation], while a diet rich in colorful plant foods may help provide antioxidant protection that supports healthy aging.
