Alcohol consumption increases the risk of major causes of death in Chinese men, including deaths from cardiovascular diseases, certain cancers, and liver diseases, according to a new study by researchers from Oxford Population Health and Peking University. The study is published today in The Lancet Public Health.
The use of alcohol is estimated to be responsible for about 3 million deaths worldwide each year, and it is increasing in many low- and middle-income countries such as China. However, some previous studies indicate that moderate alcohol consumption of about one-two drinks a day may be associated with lower risk of death, particularly from coronary heart disease, leading to a belief that moderate alcohol drinking is beneficial to health.
The study shows that alcohol use causes higher risks of death from cardiovascular diseases, particularly stroke, certain cancers including oesophageal cancer, liver diseases, and deaths overall, in men in China. The findings of this study demonstrate the influence that alcohol consumption may have on deaths in populations around the world.
The researchers used data from the China Kadoorie Biobank (CKB), a collaborative study of over 512,000 adults recruited during 2004-08 from ten diverse urban and rural areas across China. Study participants were interviewed about their lifestyle and behaviours, including detailed alcohol drinking patterns. Around one-third of men, but only 2% of women, drank alcohol regularly (ie at least once a week). The researchers comprehensively assessed the effects of alcohol use on specific causes of death in men identified through linkage to death records over a period of about 12 years.
The researchers undertook a genetic analysis to clarify whether or not alcohol intake was responsible for causing deaths. In East Asian populations, there are common genetic variants that greatly reduce alcohol tolerability, because they cause an extremely unpleasant flushing reaction after drinking alcohol. People with these genetic variants tend to drink less alcohol and because these genetic variants are unrelated to other lifestyle factors (such as smoking or socioeconomic status), the researchers can use this information to more accurately assess the cause-and-effect relationships of alcohol with a wide range of diseases.
- Higher self-reported alcohol intake was associated with higher risks of death overall, and from many specific causes of death including cardiovascular diseases, certain cancers, and liver diseases in 20,000 men who died during the 12 years of follow-up;
- The genetic analyses provided evidence for a dose-dependent causal effect of alcohol use, with one-two drinks a day associated with 15% higher risks for cardiovascular deaths, 12% for cancers known to be related to alcohol, 31% for liver disease, and 7% for deaths overall;
- There was no genetic evidence that moderate drinking (ie 1-2 drinks a day) had protective effects for any causes of death, including coronary heart disease;
- As few women in China drink alcohol (less than 2% of women in the study drank regularly), women in this study provided a useful control group in the genetic analyses. This helped to confirm that the excess risks of death in men were caused by drinking alcohol, and not by some other mechanisms related to the genetic variants.
Iona Millwood, Associate Professor at Oxford Population Health and a lead author of the study, said ‘Our study found no evidence that moderate drinking causes health benefits. It is becoming clear that the harmful use of alcohol is an important risk factor for premature death, both in China and globally.’
Professor Zhengming Chen, Richard Peto Professor of Epidemiology at Oxford Population Health and a senior author and CKB co-PI, said ‘This study provides important causal evidence of the scale of alcohol-related deaths, which is critical to inform public health prevention strategies in different countries.’
Professor Liming Li, a senior author and CKB co-PI from Peking University, said ‘Levels of alcohol consumption are rising in China, particularly among men. This large collaborative study demonstrates a need to strengthen alcohol control policies in China.’