Lifestyle

Common risk factors for developing Alzheimer's disease

Researchers say there is a growing global risk of Alzheimer's disease.

It is estimated that 36 million people suffer from the disease worldwide. Predictions are that those numbers will triple by the mid-century.

Although the causes of Alzheimer's disease are not yet fully understood, it is becoming increasingly evident that diet and lifestyle choices play a more significant role than previously thought. Altogether seven lifestyle-related risk factors were identified based on a new mathematical model that was developed by a research team from the University of California, San Francisco (UCSF). They are: Physical inactivity (21 percent), depression (15 percent), smoking (11 percent), hypertension (8 percent), obesity (7 percent), low education (7 percent) and diabetes (3 percent). These risk factors combined are believed to contribute to about 5.5 million cases of Alzheimer's in the United States alone.

Based on findings such as these, the Alzheimer's Association has pledged to fund more studies to explore the importance of mental and physical health for risk reduction and ultimately prevention of the disease.

One area on which researchers have been able to shed some light is the connection between Alzheimer's and cardiovascular disease. Autopsy studies have shown that 80 percent of Alzheimer's patients suffered from cardiovascular disease or related conditions like high blood pressure, heart disease, high cholesterol and stroke.

"Taking care of your heart protects your brain," said Dr. Jack C. de la Torre, a leading researcher in the field. He believes that reducing cardiovascular risk factors as early as possible is key in the prevention of memory loss and dementia in later years. There is general agreement among the experts that a healthy, balanced diet and regular exercise are the most effective measures people can take to protect their mental health.

A study report from Rush Medical College in Chicago concluded that a Mediterranean-style diet, which is dominantly vegetarian and low in fat, may have positive effects on the brain as well. For this project, 3,790 men and women ages 65 and older were periodically tested over an average of 15 years for memory and thinking skills. The participants who adhered most strictly to the Mediterranean diet scored significantly higher in the tests and were diagnosed as two years younger in "brain age" in comparison to their counterparts who didn't follow a particular diet regimen. The findings still held after adjustments were made for other risk factors like age, sex, race, education, etc.

The report, which was published in the American Journal of Clinical Nutrition, concluded that, although the research "could not account for all the many factors that may contribute to cognitive decline in old age, ... a Mediterranean diet helps cut down on inflammatory substances in the body." Inflammation has long been tied to heart disease and now possibly to Alzheimer's disease as well.

Key ingredients of the Mediterranean diet, which derives its name from the typical food choices in countries around the Mediterranean Sea, include an abundance of fresh fruits, vegetables, whole grains, nuts, legumes, olive oil and fish but only limited amounts of dairy products and meats.

The other equally important component of an anti-Alzheimer's disease lifestyle is regular exercise. A study on the benefits of physical activity for mental health, published in the Archives of Internal Medicine, found that "regular exercise may be good for staying mentally sharp into old age."

Particularly resistance training (weight lifting) was singled out as a highly effective form of exercise in a study from Vancouver, Canada. Participating seniors who engaged at least twice a week in weight lifting scored on average higher on mental acuity tests than those who did only aerobics.

Still, as other studies from the U.S. and Europe have shown, older men and women who follow a moderate to intense exercise regimen of any kind score regularly higher on cognitive tests than their sedentary contemporaries.

Alzheimer's is a complex phenomenon. Understanding it enough to hope for better prevention, let alone a cure, requires much further studying, especially with regards to its genetic components. However, since lifestyle factors almost certainly play a major role, we all can start taking steps to do our part in preventing this terrible disease.

Timi Gustafson R.D. is a clinical dietitian and author of the book "The Healthy Diner – How to Eat Right and Still Have Fun"®, which is available on her blog, "Food and Health with Timi Gustafson R.D." (www.timigustafson.com), and at amazon.com. You can follow Timi on Twitter and on Facebook.

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