Male couch potatoes, take note. Exercising vigorously
for just 3 hours a week—or, about the time it takes to watch a professional sporting event—can cut your heart attack risk by more than 20 percent, according to a recent NIH-funded study.
|Dr. Andrea Chomistek
progress in understanding and preventing coronary
heart disease (CHD), the disorder
still remains the number one cause of mortality
in the United States. According
to the National Center for Health Statistics, every 26 seconds, someone in the U.S. experiences a coronary event. Further,
more than 616,000 people in the U.S. died from CHD in 2007. The center also notes that each year, CHD takes the lives of more Americans
than cancer, lower respiratory disease and accidents combined.
Specialists in cardiovascular health have long believed that exercise, when performed regularly,
can result in significant protection for the heart. In particular, it may lessen the risk for CHD by lowering blood pressure, improving cholesterol profile (in particular, raising HDL, the so-called good cholesterol) and decreasing
triglycerides (another blood fat), reducing abdominal fat and lowering amounts of C-reactive
protein, a substance in the blood that often relates to systemic inflammation—a potential harbinger of heart disease.
In the current investigation, Dr. Andrea Chomistek
and her colleagues from Harvard School of Public Health, Harvard Medical School and Brigham and Women’s Hospital, looked at physical
activity levels and blood biomarkers associated
with cardiovascular health in men, ages 45-70, who participated in the Health Professionals
Follow-Up Study. The prospective observational
study was funded by NHLBI. Results appeared in a recent issue of Medicine and Science
in Sports and Exercise.
Among more than 18,225 men who provided blood samples, 454 participants suffered a nonfatal
heart attack or died from CHD during the study period of 1994-2004. After study exclusions, 412 men with CHD were matched to 827 controls based on age, smoking status and date of blood
“What we found was that 3 hours of intense exercise (for example, jogging, biking, racquetball) a week reduced the risk of a heart attack by some 22 percent,”
said Chomistek. The clinical significance of that finding notwithstanding,
“what came as probably the biggest surprise was the important role vitamin
D seemed to play in the relationship between exercise and incidence of CHD,” she explained.
Although HDL cholesterol accounted for 38 percent of the physical activity/CHD connection, “vitamin D was a significant contributor as well, explaining 21 percent of the association. The latter was likely due to the fact that many of the exercises men participate in tend to be done outdoors,” Chomistek added, noting that the sun is an excellent source of vitamin D.
Two other findings emerged from the study that help explain the drop in heart attack rates among the physically active. One was a reduction in apolipoprotein
B (Apo B), a substance that attaches to LDL cholesterol and helps transport it throughout the body. The other was a decline in HbA1c, a measure of insulin
sensitivity. High Apo B and HbA1c levels have both been associated with increased rates of heart disease.
Although this study was conducted only in males, ladies shouldn’t feel left out, explained Chomistek, an avid runner. Results from another recent analysis, the Women’s Health Study, showed similar benefits for physically active females.