Arthritic joints, stomach troubles and painful ankles aren't symptoms traditionally thought of as increasing the risk for Alzheimer's. But a new report found that small health troubles can combine to significantly increase the risk of developing the disease.
The report, part of the Canadian Study of Health and Aging, looked at more than 7,000 older men and women, most in their 70s, beginning in 1991. They were given extensive surveys about their physical health, as well as tests of memory and thinking, at the start of the study, in 1991, then again after five and 10 years.
The researchers found that having a mix of health problems like poor eyesight or hearing, poor fitting dentures, cough or congestion, sinus complaints foot or ankle problems, arthritis or loss of bowel or bladder control increased the risk of developing Alzheimer's and other types of dementia over the next decade.
Each of these health problems increased the risk by about 3 percent. Together, the risks added up.
Someone who began the study in good health had an 18 percent risk of developing dementia over the next 10 years. But the more minor health complaints, the higher the risk, so that someone with up to a dozen small health complaints had a 30 to 40 percent increased risk. Such health problems are common in the frail elderly. The findings were reported in Neurology, a journal from the American Academy of Neurology.
Advancing age remains the single most important risk factor for developing Alzheimer's disease. But factors that increase heart disease risk, like high blood pressure, high cholesterol, stroke and diabetes, are increasingly recognized as risk factors for dementia as well.
Other studies have shown that other factors can increase Alzheimer's risk as well. These include depression, being inactive, or feeling chronically tired, lonely or unwell. Having a spouse with Alzheimer's can also lead to poor health and increase dementia risk.
This study focused on nontraditional risk factors of Alzheimer's disease, and found that they are associated with a cumulative increase in risk for diminished cognitive function. The more health problems someone had, the greater the risk of developing Alzheimer's or other forms of dementia, or of dying. Having a moderate number of health problems also increased the risk of developing mild cognitive impairment, which can lead to Alzheimer's disease.
It's unclear why seemingly unrelated health problems may affect the brain. Stress may be a contributing factor and underlie many health problems. The authors note that people with many small illnesses may also be less able to heal and repair deficits, including those affecting the brain. It is not clear, however, whether the health problems under study helped cause Alzheimer’s or whether they were symptomatic of some other underlying cause.
The results, nevertheless, highlight the importance of looking at overall health and well-being in seniors, the authors note. Maintaining good physical health in later years, through regular activity and a wholesome diet, may be good not only for the body, but also the brain.
Source: Xianwei Song, Arnold Mitniski, Kenneth Rockwood: "Nontraditional Risk Factors Combine to Predict Alzheimer Disease and Dementia." Neurology, 2011, Volume 77, pages 227-234.