Older obese adults who are in good cardiovascular shape have a lower risk of death than those who are of normal weight but are out of shape, finds a new study.
The research, published in the Journal of the American Medical Association, finds that adults over age 60 who have higher levels of cardiovascular fitness live longer than unfit adults, regardless of their body fat levels.
Dr. Xuemei Sui, of the University of South Carolina, Columbia, wanted to know how cardiovascular fitness and body fat affect death rates in women and men over the age of 60.
The team looked at 2,603 adults, about 20 per cent of whom were women. At the start of the study, the volunteers' fitness levels were assessed, their waists measured, and their body fat percentages calculated.
Over the next 12 years, there were 450 deaths. The researchers found that those who died were more likely to have lower fitness levels, and more cardiovascular risk factors than survivors.
In fact, death rates for those with higher fitness levels were less than half the rates for those who were unfit.
Participants in the higher fitness groups were, for the most part, less likely to have risk factors for cardiovascular disease, such as hypertension, diabetes, or high cholesterol levels.
Interestingly, the researchers also found that body fat alone had no effect on the likelihood of an early death.
"Our data therefore suggest that fitness levels in older individuals influence the association of obesity to mortality," the authors write.
Only those who were severely obese, or who had a lot of abdomidal fat did not appear to benefit. That fact rings true for Dr David Lau of the Canadian Obesity Network, who warns that no matter how fit you are, being very overweight can be dangerous.
"We know from a number of other epidemiological studies that overweight and obsesity are certainly associated with a shorter life span," he says.
The authors say the important message to take away from this study is that it may be possible to prolong the life of older adults, including those who are obese, just by promoting regular physical activity, such as brisk walking for 30 minutes or more on most days of the week.
That kind of exercise should keep most individuals out of the low-fitness category.
The findings don't surprise fitness expert Dr. Mark Tarnopolsky, a professor in the department of kinesiology at McMaster University in Hamilton, Ont.
"Exercise is not just targetting one tissue. It has a systemic effect, affecting the heart, the lungs, skeletal muscles -- and even the brain can be favorably affected by exercise."
