Alcohol plays an important part in the social life of humans, and from early life on. Any minor and major life event is celebrated with alcohol, and many friendships and business deals are formed over a drink. However, the strong role that alcohol plays in our daily life might make it difficult to objectively assess its less positive effects on us, such as its influence on health.
While drinking large amounts of alcohol is generally considered bad for one’s health, it has also been assumed that moderate consumption could pose health benefits. There is even scientific evidence suggesting some advantages of moderate alcohol consumption over abstinence, for example in reducing the risk for type-2 diabetes. However, in an ambitious 27-year study published in BMC Public Health, Karina Nygren and colleagues from the University of Umeå in Sweden have now refuted this suggestion.
By documenting the drinking habits of more than 800 persons in a mid-sized Swedish community from the age of 16 to the age of 43, the researchers were able to show that medium alcohol consumption did in fact not help to prevent diabetes – the level of glucose in one’s blood (which can be an early indicator for type-2 diabetes risk) was no lower for participants that reported consuming medium amounts of alcohol between the ages 16 to 43 than for those who had only consumed little alcohol in those years.
Interestingly, this study also allowed new insight to how long-term drinking behavior might have different effects on women and men. Although the men included in the study consumed much more alcohol than the women, and more men than women reported binge-drinking, it might be female heavy drinkers that are especially at risk for developing type-2 diabetes.
The women who reportedly drank the highest volumes of alcohol between the ages 16 to 43, and also those who consistently engaged in binge-drinking in that period, showed higher levels of glucose in their blood than women who drank less amounts of alcohol.
This relationship was not affected by whether or not a woman had a high body mass index (BMI) or high blood pressure, which in turn were the two main factors affecting high blood-sugar levels for men. Furthermore, exercise and smoking habits, both in adolescence and in adulthood, had no effect on blood-sugar levels for either men or women.
The longitudinal design of this study made it possible to explore the relationships between drinking behavior and diabetes in a way that was previously not possible, and it highlights the effects of chronic drinking on health. The study has its caveats: for example, it is difficult to say exactly why heavy drinking promotes higher blood-glucose levels without gathering additional data about liver function, insulin resistance or other related factors. Furthermore, the researcher had to estimate the likely alcohol consumption per year, from the interviews that were conducted every 3 to 13 years, which might have led to an over- or underestimation of the true alcohol intake over the years.
Nonetheless, the results presented by Nygren and her colleagues demonstrated that alcohol consumption patterns formed in adolescence may persist into later life and can thus affect the susceptibility for diseases such as diabetes from an early age on. Interventions to reduce binge-drinking and high alcohol consumption are beneficial across all ages but may be especially effective if targeted at young women, to prevent the development of a habit of heavy drinking.