Poverty and alcohol a bad mix for the heart
If you have a low income and education, drinking can be bad for your heart. But researchers think the health problems they have found may reflect something other than the effects of alcohol.
It’s long been a maxim that a glass of wine can be good for your heart. But take a deeper look at this accepted wisdom and it becomes clear that this is only partly true. For example, researchers now know that wine is only good for your heart if you work out.
The newest twist on this old wisdom relates to socioeconomic status: moderate drinking is good for your heart only if you have a decent income and education.
More specifically, if you have a very modest income and little education and drink alcohol four to seven times a week, you have a significantly higher risk of dying of cardiovascular disease than others.
A new Norwegian study shows that the dangers or benefits of regular alcohol consumption are linked to social backgrounds.
"It may be that this link is not due to the alcohol itself, but lifestyle," says Eirik Degerud, a postdoc at the Norwegian Institute of Public Health, who was the first author of the study.
Best to be rich
Degerud and colleagues from several research institutes analyzed three surveys from 1987 to 2003 about the drinking habits of more than 200,000 Norwegians born before 1960. They have also examined the Norwegian Cause of Death Registry to determine causes of death.
The researchers divided the population into three, based on economic class and education. People in middle and upper social classes who drink every day actually have a lower risk of dying from cardiovascular disease than those who rarely drink. This is especially true for those with the most money and education.
That certainly suggests it could be good for the heart to drink, but Degerud also thinks part of the explanation lies in the fact that this group generally lives more healthy lives.
In fact, genetic studies show that moderate amounts of alcohol provide a protective effect against myocardial infarction for only about 15 per cent of the population.
Additionally, if people who drink less often than once a month have a higher risk of dying from cardiovascular disease, it may be that the individual had a disease or that they drank a lot previously, but stopped — and that the delayed effects of alcohol consumption then appeared.
But the researchers do not know if this supposition is true or not.
The alcohol paradox
Research has clearly demonstrated that people from lower socioeconomic classes suffer more than their more well off peers from the harmful effects of alcohol. In Norway, they tend to drink less often than others, but are more likely to be admitted to hospitals due to alcohol-related events, such as acute alcohol poisoning. This is called the alcohol damage paradox.
Degerud was thus surprised to discover that this less well-off group also has a higher risk of cardiovascular disease if they drink as often as those in higher socioeconomic classes.
But Degerud can’t say for certain if it’s the alcohol or something else in their lifestyle that increases the risk. He and his colleagues have checked other known risk factors, such as smoking, physical activity, diabetes, previous cardiovascular disease and the person and his or her family, blood pressure, heartbeat and cholesterol.
"Both diet and mental health may possibly have an effect," says Degerud.
Diet, lifestyle, stress all possible factors
Thomas Clausen is a professor of medicine and head of Center for Addiction Research at the University of Oslo (UiO). He believes that lifestyle likely plays a large role in cardiovascular health.
"A few glasses a day may be beneficial for your blood pressure, but it's probably not primarily the alcohol that promotes the health of the upper social classes," he says.
"I think that a lot of negative lifestyle factors add up for people in lower socioeconomic classes, from diet to job related stress,” he said.
Clausen said, however, that the study does not have enough detail to answer the question of what about alcohol consumption causes premature deaths due to cardiovascular disease in lower socioeconomic classes.
“Although they have done a good analysis, the surveys they are based on are not designed to answer this question,” he said.
For example, participants were only asked once about how often they drink, mostly when they were in their 40s. Thus, the researchers do not know how much alcohol they consumed throughout their lives.
Two other researchers, however, wrote a commentary in the same academic journal, Plos Medicine. They stated that the study provides an important piece of the puzzle in understanding why people from lower social classes are more likely to have shorter lives.
This commentary also notes the Degerud study makes it clear that “it is not appropriate simply to extrapolate from risks associated with alcohol use in higher-income populations to address lower-income populations in which the impact of alcohol use is largest.”
-------------------------------------
Read the Norwegian version of this article at forskning.no.
Scientific links
- Eirik Degerud et al.: Life course socioeconomic position, alcohol drinking patterns in midlife, and cardiovascular mortality: Analysis of Norwegian population-based health surveys. Plos Medicine, 15(1), 2 January 2018. Doi: 10.1371/journal.pmed.1002476.
- Jürgen Rehm and Charlotte Probst: What about drinking is associated with shorter life in poorer people? Plos Medicine, 15(1), 2 January 2018. Doi: 10.1371/journal.pmed.1002477
