BOSTON, May 20 (UPI) -- While recent studies have shown that luck plays a large role in whether a person gets cancer, new research suggests changing lifestyle habits could have just as preventive an effect as winning genetic roulette.
Not smoking, moderating alcohol consumption, maintaining a healthy weight and getting physical activity can cut the risk of death in half, according to an analysis of two large studies by researchers at Harvard University.
The new study contrasts one published last year suggesting just one-third of cancer risk can be mitigated by changes to lifestyle, with the rest being chalked up to "bad luck." The study said that while genetic and other cues could have an effect, most cancer is due to random cell mutations which are not preventable.
Researchers involved with the new study say, however, that while luck and random changes play a large role in cancer, actions to lower the chance for those changes can be effective if previous research is taken into consideration.
"We should not ignore the knowledge we already learned over the past decade, or the past 100 years," Mingyang Song, a research fellow in the U.S. Department of Nutrition, told the Washington Post. "We should use this knowledge to move the policy forward and also make the public aware that we already have this knowledge and we can utilize this knowledge, to improve the current cancer prevention effort."
For the study, published in the journal JAMA Oncology, researchers reviewed data on 89,571 women and 46,339 men collected as part of the Nurses' Health Study and the Health Professionals Follow-up Study, comparing records with national cancer statistics in the United States for associations between lifestyle, cancer and mortality.
After defining a "healthy lifestyle" as never smoking cigarettes or having quit, one drink per day for women or two drinks per day for men, BMI between 18.5 and 27.5 and at least 75 to 150 minutes of aerobic physical activity per week, researchers organized participants into groups at low or high risk for cancer.
Overall, women in the low-risk group had a 25 percent risk for cancer and those in the high-risk group had a 48 percent chance, while men in the low-risk group had a 33 percent risk and the high-risk had a 44 pecent chance.
When comparing the results against the entire United States population, the researchers estimate 41 percent of cancer cases among women and 59 percent of deaths are preventable, while among men 63 percent of cases and 67 percent of deaths could be prevented.
"Cancer is preventable," researchers from the Washington University School in St. Louis wrote in an editorial published with the study in JAMA Oncology. "In fact, most cancer is preventable -- with estimates as high as 80 percent to 90 percent for smoking-related cancers, such as lung and oropharyngeal cancer, and as high as 60 percent for other common, lifestyle-related cancers, such as colorectal and bladder cancer. This large excess of cancer is not inevitable but rather can be tackled by a broad range of interventions at multiple levels, including strategies at the clinician level, the individual level, the community level, and the society level through regulatory change."