Study IDs four ways to cut disease risks

NEW YORK, 17 aug 2009– Want to take health care reform into your own hands? Don't smoke, lose weight, get exercise, and stick to a good diet, says a new study. The advice may sound familiar, but people with those four habits have a dramatically lower risk of chronic diseases such as diabetes and heart disease.

"Living a healthy lifestyle -- never smoking, maintaining a recommended (weight), performing adequate amounts of physical activity, and adhering to healthy dietary principles -- has a tremendous beneficial impact in preventing or delaying major chronic diseases," said Dr. Earl Ford, of the Centers for Disease Control and Prevention.

To give a sense of the benefit, the rate of chronic diseases ranged from about a half a percent per person per year studied for those with all four habits to about 3% per person per year studied for those who had none of them.

Ford and his colleagues recently completed a study in more than 23,000 middle-aged Germans which showed that people who adhered to all four healthy habits had a 78 percent lower risk of developing a chronic disease compared to study participants without any of the healthy habits.

Encouragingly, Ford points out, "Although the largest reduction in risk is found among people who practice all four of these lifestyle factors, benefits are also gained by adding one healthy behavior at a time."

On average, for example, the presence of just one healthy behavior as compared with none cut the chronic disease risk in half.

Between 1994 and 1998, Ford and colleagues from the German Institute of Human worked with 23,153 adults between the ages of 35 to 65 years, the researchers looked for the following characteristics: never smoked; had a body mass index (a measure of the ratio of weight to height) lower than 30; did at least three and a half hours per week of physical activity; and adhered to healthy dietary principles (high intake of fruits, vegetables, and whole grains, and low meat consumption).

Most participants had one to three of these health factors, fewer than 4 percent had zero healthy factors and 9 percent had all four factors.

Then, roughly eight years later, the investigators analyzed the relationship between these habits and participants' risk of developing diabetes, heart attack, stroke, and cancer.

In the intervening years, 871 participants (3.7 percent of the total) developed new cases of diabetes, 868 (3.8 percent) developed cancer, 214 (0.9 percent) had a first heart attack, and 195 (0.8 percent) had a stroke.

In the Archives of Internal Medicine, the researchers report that people with all four healthy lifestyle factors at the start of the study had a 93 percent lower risk of developing diabetes, an 81 percent lower risk of a heart attack, half the risk of stroke, and a 36 percent lower risk of cancer compared to subjects without any healthy factors.

The reductions in risk were similar for men and women.

Various combinations of healthy behaviors also improved individuals' risks. For example, compared to having no healthy lifestyle factors, having a BMI lower than 30 and participating in physical activity for at least three and a half hours/week reduced the risk of developing a chronic disease by 64 percent. Similarly, physical activity and good dietary behavior reduced the risk by 66 percent.

Some factors appeared to protect more against specific diseases than others. A BMI lower than 30 was a particularly strong protective factor against development of diabetes, for instance. Physical activity protected more strongly against diabetes and heart attack than against cancer. Following good dietary principles provided a similar degree of protection against diabetes, stroke, and cancer.

The largest reduction in risk was associated with having a BMI lower than 30, followed by never smoking, at least 3.5 hours of physical activity and then adhering to good dietary principles.

Admittedly, Ford said, the researchers only looked at participants' behaviors at the beginning of the study, without checking to see whether their habits had improved or worsened. "Thus," he said, "our results are probably most applicable to people who do not often change their behaviors for the better or the worse."

He added, however, that other studies have shown that risks for disease are reduced as healthy behavior improves.

Furthermore, while the study was done in Germany, its results match those of studies done in the US, Ford said, so "it is not unreasonable to think that the lessons from our study apply to United States adults as well. The exact risk estimates might vary a bit, but then such risk estimates also vary among United States studies."

SOURCE: Archives of Internal Medicine, August 10/24, 2009.