Cancer most often develops from a combination of genetic and environmental factors. Our diets are one factor that have been shown to affect our chance of cancer. Alcohol is a factor whose health benefits are mixed. Some studies have linked moderate alcohol use to certain health benefits while others associated alcohol with increased risk of certain cancers.
Researchers from China wanted to investigate the link between alcohol and death due to cancer. The systematic review, published in Annals of Oncology, found that heavy drinking was associated with an increased risk of cancer death, while light drinking was associated with a decreased risk.
The systematic review included 18 cohort studies that evaluated the relationship between alcohol and cancer mortality. Participants filled out surveys that indicated the amount of alcohol they consumed on a daily basis. They were then followed for death due to cancer. Compared to those who did not drink or only drank occasionally:
A systematic review is generally a very reliable form of research since it pools data from several smaller studies. Larger number of participants increase the reliability of outcomes. However, the review is only as reliable as the studies included in the review. The studies included in this trial were observational trials. Researchers do not influence what each person does, but simply observes the participants so outcomes can not be confirmed as cause and effect. Instead, they can only be used to suggest a relationship between studied factors.
Since this review was based on observational studies, it does not prove that heavy alcohol consumption leads to cancer death . However, heavy alcohol consumption is associated with a variety of other health conditions, both short term like alcohol poisoning and long term like liver failure. The decrease in cancer death in light drinkers compared to those that do not drink was fairly small and should not necessarily lead you to drinking for the sake of cancer prevention. However, if you drink, aim for moderate alcohol use. This is up to 1 drink per day for women and up to 2 drinks per day for men.