Higher levels of physical activity may be associated with a lower risk of many types of cancer, according to a study published recently in JAMA Internal Medicine.

The study was conducted by Steven C. Moore, PhD, MPH, of the National Cancer Institute, who, along with his research team, looked at data from 12 US and European cohorts (groups of study participants) along with the participants’ self-reported physical activity, during the time period from 1987 to 2004.

Among the 1.4 million participants in the 12 cohorts, Moore and his team analyzed the associations of physical activity with the incidence of 26 kinds of cancer. During the 11 years of follow-up, the team identified 186,932 cancers, according to a media release from The JAMA Network Journals.

Per the authors’ analysis, they suggest that higher levels of physical activity, compared to lower levels, were associated with lower risks of 13 of 26 cancers: esophageal adenocarcinoma (42% lower risk); liver (27% lower risk); lung (26% lower risk); kidney (23% lower risk); gastric cardia (22% lower risk); endometrial (21% lower risk); myeloid leukemia (20% lower risk); myeloma (17% lower risk); colon (16% lower risk); head and neck (15% lower risk), rectal (13% lower risk); bladder (13% lower risk); and breast (10% lower risk).

Most of the associations remained regardless of body size or smoking history, according to the study. Overall, a higher level of physical activity was associated with a 7% lower risk of total cancer, per the release.

However, a higher risk of cancer among the physically active—a 5% higher risk of prostate cancer and a 27% higher risk of malignant melanoma—was noted in regions of the US with higher levels of solar UV radiation. This risk was not noted in regions with lower levels, the release states.

A drawback to the study, the authors note in the release, is that they cannot fully exclude the possibility that diet, smoking, and other factors may affect the results. Also, since the participants analyzed in the study self-reported their amount of physical activity, thee could be errors in recall among the results.

However, the big picture from the study is, “These findings support promoting physical activity as a key component of population-wide cancer prevention and control efforts,” the authors state in the release.

[Source(s): The JAMA Network Journals, Science Daily]