Cancer Mortality - reduction

Today I reviewed a study that in some ways can be considered a gold standard. The positives of the study include that the sample size was large, over 3000 persons; the study was long, 16 years; and it followed people over time forward before disease occurred. A less respected way to study disease cause is to look back at people's exposures after the illness is identified, or retrospectively. This study is far from perfect. It only involves one geographical area and one gender, which some may say prevents generalizing the results to other people. I feel that the results will likely be repeated in other populations. The study also relies on self report from the participants though there were trained assistants conducting interviews. These are not, however, clinical measures. The study is thus a cross between an experimental control study and an epidemiological study. The results should however, turn your head.

In regards to cancer mortality, (not getting cancer, but dieing from it) the intensity as well as the duration of physical activity is protective. Other variables related to cancer outcomes were isolated, or taken out of the equation so that the data ONLY looked at the effect of this variable - exercise. The other factors, so you know that they are an issue, are weight, alcohol consumption and smoking status. The intensity of the exercise was measured in MET. This was mentioned in a recent blog and stands for the metabolic equivalent of oxygen consumption. The researchers identified several forms of exercise and then determined what level of MET to apply to them. This is a good follow up to the previous blog because the exercises that they found protective had METs over four and included, jogging at a 10, swimming and rowing at about 5.5 and cycling at 5.1. I am surprised that swimming was that high, but we do it for less time usually. Skiing and playing ball games was at about 9. Walking came in at a 4.2 but that may have been leisure or work related walking.

Bottom line was a significant reduction in deaths from cancer in those men who had consistently exercised 30 minutes a day at a moderate intensity. The activities listed above. In fact, the lead researcher was quoted,
"We found a 50% reduction in the risk of dying prematurely from cancer," Dr. Kurl pointed out. Exercise also improves well being and confidence, and leads to better sleep and weight control, he added. He also told the interviewer that he jogged three times a week and did weight training at the gym twice a week.

so now you know. Exercise: the more you do the more you get...