Mean 10 years of follow-up
The new study is the first to examine physical activity, drinking, and the 10 cancers that have been linked to alcohol consumption (oral cavity, throat, larynx, esophagus, liver, colorectal, stomach, breast, pancreas, and lung).
The authors used data from 10 British population-based health surveys from 1994-2008 and looked at adults aged 30 years and older. The mean follow-up period was 9.9 years.
Among 54,686 participants, there were 2039 alcohol-related site-specific cancer deaths.
Alcohol consumption categories were based on U.K. guidelines, with 1 unit equal to 8 grams (about 2 ounces) of pure alcohol. The categories were as follows: drinking within guidelines (<14 units/week for women, <21 units/week for men), hazardous level (14-35 units/week for women, 21-49 units/week for men), and harmful level (> 35 units/week for women, >49 units/week for men). The survey also queried participants about being ex-drinkers, occasional drinkers, and never drinkers.
Physical activity was assessed using self-reported accounts of the 4 weeks preceding the health survey and intensity of activity (light, moderate, or vigorous) was queried. Physical activity was categorized using the upper (15 MET-hours/week) and lower (the aforementioned <7 MET-hours/week) recommended limits.
The median age of participants was 51 years; 7.9% were never drinkers and 14.7% exceeded guideline amounts. For physical activity, 23% reported none. The median level of activity was 9 MET-hours/week.
The authors say that the “increased risks [among the harmful, hazardous, and ex-drinker categories] were eliminated” among the individuals who reported physical activity >7.5 MET-hours/week. That meant the hazard ratios for cancer mortality for each category were reduced to the point that they were no longer statistically significant.
For example, for all drinkers in the “hazardous” category, the risk of cancer-related mortality was significantly higher than for nondrinkers (with a hazard ratio of 1.39), but in the subgroup of these participants who were physically active at the lower recommended limit, the hazard ratio dropped to 1.21.
These “broad patterns of effect modification by physical activity persisted when the upper physical activity limit [15 MET-hours/week] was used,” write the authors.
The new study adds to the literature on cancer mortality and alcohol consumption. In another recent study, researchers looked at eight British cohorts and reported overall cancer mortality associated with alcohol consumption was eliminated among those meeting physical activity recommendations (Br J Sports Med. 2017;51:651-7). The new study added two more cohorts to this base of eight and only focused on cancers that have been linked to alcohol consumption. The earlier study included deaths from all types of cancer.
The refinement of focus in the current study is important, say Dr. Stamatakis and colleagues.
“This specificity adds biological plausibility and permits a more immediate translation of our findings into policy and practice,” they write.
Dr. Stamatakis practices what he advocates, but is not a teetotaler.
“I exercise (e.g., dynamic yoga, HIIT cardio workouts, run, cycle, lift weights) for 45-60 minutes a day and I walk 8,000-14,000 steps daily. That would categorize me perhaps in the top 3%-5% for my age/sex group. And I enjoy 1-2 cans of craft beer a couple of times a week,” he said in an email.
Dr. Stamatakis and Dr. Patel have reported no relevant financial relationships.
This article first appeared on Medscape.com.