FRIDAY, Nov. 7, 2008 (HealthDay News) -- Everyone knows smoking and being obese is not healthy for you, but now a new study shows the odds of dying early are highest among obese smokers.
"We know that obesity and smoking by themselves are important health risk factors," said lead researcher Annemarie Koster, an epidemiologist at the U.S. National Institute on Aging. "We found that smoking and obesity are independent predictors of mortality, but smoking and being obese especially increases the mortality risk."
Smoking and obesity both carry a significant mortality risk, but particularly smoking, Koster said. "It seems that smoking cessation was associated with significantly lower mortality risk in every weight group," she said. "Quitting smoking will definitely improve your mortality risk, no matter in what weight group you are."
Losing weight will also lower mortality risk, Koster said. "Both losing weight and quitting smoking will increase your health and lower your mortality risk," she said.
The report was published in the November issue of The American Journal of Clinical Nutrition.
For the study, Koster's group collected data on 3.5 million members of the AARP, aged 50 to 71. In 1995-1996, and again in 1996-1997, AARP sent out questionnaires asking people about diet, family history of cancer, physical activity, hormone replacement therapy, weight, waist size, and smoking.
Using the U.S. Social Security Administration Death Master File, the researchers linked the AARP data with death records of the survey participants from 1996 to 2006. During that period, almost 20,000 men and 7,500 women died.
The researchers found that as weight increased, so did the rate of death. Across all weights, people who smoked had the highest death rates.
In fact, obese smokers had a six to eight times greater risk of dying compared with normal weight people who never smoked. In addition, among smokers with a large waist, the risk of dying was five times greater than among people with the smallest waists who never smoked, Koster's team found.
Dr. Norman H. Edelman, a professor of preventive medicine, internal medicine, physiology & biophysics at Stony Brook University in New York and chief medical officer at the American Lung Association, thinks that if you have to choose between losing weight or stopping smoking, you should stop smoking.
"Especially important is the finding that smoking cessation has a great effect on lowering risk of dying, one which far outweighs the slight increased risk from the associated increase in weight," Edelman said. "Also to note, if one is obese and smokes and has to choose between weight loss and smoking cessation to improve health, the latter will have a greater protective effect," he added.
Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine, agreed that people can do simple things to improve their health and life span.
"We have long known that a surprisingly short list of potentially modifiable behaviors holds sway over an enormous range of mortality risk," Katz said. "Together, tobacco use, physical activity and dietary pattern are major determinants of the probable quality, and quantity, or our lives."
This report reaffirms the strong interactive effects of smoking and excess body fat on the risk of death, Katz said.
"If you are overweight and smoke, fixing either one can markedly improve your chances for a normal life span," Katz said. "Fix both, and the probability of benefit is huge. The message is clear: We all have the power to choose a better medical destiny."
For more information on smoking, visit the U.S. National Institutes of Health.