Alcohol use is responsible for about 4 per cent of global burden of disease. But current drinking has been found to disproportionately raise the risk of cardiovascular disease, cancer and injury in people living in low-income countries (LICs) such as India and Zimbabwe and lower-middle-income countries (LMICs) such as China and Colombia.
Till date, all epidemiological studies on the impact of alcohol consumption on health have been restricted to high- and middle-income countries. For the first time, a study published a few days ago in the journal The Lancet looked at its impact on people living in countries of all income levels.
“Our study did not look at the association between alcohol and one disease but at the overall effect of alcohol,” said Dr. Rajesh Kumar a co-author of the paper from the Chandigarh-based Postgraduate Institute of Medical Education and Research, School of Public Health (PGIMER). While 38 per cent current drinking was associated with increased risk of cardiovascular disease, cancer and injury in LICs and LMICs combined (herein called lower-income countries), it was only 16 per cent in the case of high-income and upper-middle-income countries combined (herein called higher-income countries).
The higher risk in people living in lower-income countries compared with those living in higher-income countries was seen despite the fact that more than three-quarters of participants in higher-income countries consumed alcohol vis-à-vis just one-eighth in lower-income countries. Despite the lowest prevalence of drinking in lower-income countries, participants from these countries had the highest prevalence of high-intake and heavy episodic drinking.
Both high-intake and heavy episodic drinking were associated with increased risk of overall mortality. “Our study confirms that high alcohol consumption is associated with increased risk of mortality, cancer, and injury, and a non-significantly reduced risk of myocardial infarction,” they write. A reduction in heart attack risk was seen with low or moderate intake but not with high intake of alcohol. If any, there was a heightened risk of mortality with high intake of alcohol.
Another major difference between current drinkers in lower-income and higher-income countries was concerning the type of alcohol that they consumed. For instance, the percentage of people consuming liquor and wine was 89 per cent and 3 per cent respectively in countries like India (lower-income countries) compared with 10 per cent and 61 per cent respectively in higher-income countries.
People who consumed liquor seemed to have “higher hazards of mortality, stroke, cancer, injury, admission to hospital and the composite” compared with wine or beer consumers. “Wine drinkers generally had the lowest hazards for cardiovascular disease, including a significantly reduced risk of myocardial infarction, compared with never drinkers,” they write.
Current drinkers in lower-income countries like India were younger, more likely to be male, less educated and more likely to be current smokers, and have lower body-mass index and higher blood pressure than those in higher-income countries.
“Although current drinking was associated with a 24 per cent reduced risk of heart attack, there was no reduction in risk of mortality or stroke, and current drinking was associated with a 51 per cent increased risk of alcohol-related cancers and a 29 per cent increased risk of injury in current drinkers,” notes a release.
The data came from 12 countries participating in the Prospective Urban Rural Epidemiological (PURE) study, a prospective cohort study of individuals aged 35-70 years. The median follow-up was 4·3 years and current drinking was reported by 36,030 individuals from all income levels.