Alcohol consumption increases the risk of developing several kinds of cancer. In 2020, 4% (741,300) of new cancer cases worldwide were related to alcohol consumption. 

Meanwhile, overweight and obesity are linked with an increased risk for 13 types of cancer that make up over 40% of all cancers diagnosed in the United States.

Now new findings from an observational study presented at this year’s European Congress on Obesity in Maastricht, Netherlands, suggests that for people who meet the criteria for overweight or obesity, alcohol consumption, even within recommended guidelines, is particularly risky. The research has not yet been published.

Elif Inan-Eroglu, PhD, from the University of Sydney, Australia, and colleagues, used data from the UK Biobank prospective cohort of 399,575 participants ages 40 to 69 who did not have cancer when the study started; 55% of participants were female.

Participants were split into three groups depending on their body mass index, or BMI, body fat percentage and waist circumference. They were further classified according to self-reported alcohol consumption (never drinkers, former drinkers, those who drank within U.K. guidelines of 14 units of alcohol per week and those who drank more than 14 units per week) to examine the combined effects of alcohol and obesity on 21 types of cancer (13 obesity-related cancers and eight alcohol-related ones). After an average 12-year follow-up, 17,617 participants had developed alcohol-related cancer and 20,214 had obesity-related cancer.

The study confirmed the link between obesity and cancer and found that higher obesity levels corresponded with a higher risk for cancer—regardless of alcohol consumption. For people with overweight or obesity, however, alcohol consumption posed a greater cancer risk.

Compared to those with the lowest body fat percentage who never drank, people in the highest body fat percentage who drank within the recommended alcohol guidelines were 53% more likely to develop alcohol-related cancers. Those who drank more than recommended amounts were 61% more likely to develop one of these cancers. Across all obesity markers, people with a higher percentage of body fat who drank above the average recommended guidelines had a higher risk for cancer.

Researchers point out that current guidelines do not reflect the degree of cancer risk from the combined effects of alcohol and obesity. “With around 650 million adults living with obesity worldwide, this is a hugely important issue,” Inan-Eroglu said in a news release, while acknowledging that “further research is needed to better understand the underlying mechanisms behind this joint effect of alcohol intake and obesity on cancer risk.”

Nonetheless, Inan-Eroglu said, “Alcohol drinking guidelines need to acknowledge that two thirds of the U.K. adult population are overweight or obese and consider specific recommendations to increase public awareness of the link between alcohol and cancer risk in this group. From a cancer-prevention standpoint, the safest level of alcohol consumption is total avoidance,” Inan-Eroglu said.

To learn more about obesity and cancer risk, click here.

To learn more about alcohol and cancer risk, click here.