Wealth brings with it many privileges and, according to a new public health study, one of them is a greater likelihood of heart disease for lower classes.

A new study published Tuesday in PLOS Medicine suggests that alcohol consumption affects the rich and the poor differently.

The findings come from Norway, where a research team led by Eirik Degerud from the Norwegian Institute of Public Health found that very frequent alcohol consumption (4-7x per week) was linked to increased risk of death from heart disease — but only for the lowest socioeconomic classes.

In the study, Degerud and colleagues analyzed the socioeconomics, health, and cause of death data of 207,394 Norwegian adults born before October 15, 1960 that completed mandatory censuses between 1960 and 1990.

Oslo, Norway

While the study focused on Norway, Degerud told Inverse in an email that he expected the results would be similar, but even more “dramatic in other countries where the socioeconomic differences are larger.” Norway is consistently ranked in the top five most equal places in the world, according to the widely accepted Gini Index, Palma Ratio, and World Happiness Indexes. The United States, meanwhile, was recently ranked as the 23rd out of 30 developed nations for inequality.

The data showed that study participants from the lower classes drank less, and were more likely to not drink at all, than those in middle or high socioeconomic classes. Despite this, they still experienced more alcohol-related hospitalizations and deaths.

The data also showed that people in lower socioeconomic positions were typically older, more likely to be female, more likely to have other diseases and risk factors for heart disease. Meanwhile, those higher on the socioeconomic totem pole had the lowest prevalence of risk factors for heart disease, drank more frequently, and were more likely to binge drink.

The team put forth a number of hypotheses to explain these findings, and one of their theories involved potentially different drinking behaviors among different socioeconomic classes. If higher-class drinkers were more likely to drink with a meal, for example, this could help the body metabolize the alcohol more easily, which would decrease the risk for disease. This was just one theory, however, and it was not tested.

The research did find that, across the socioeconomic spectrum, binge drinkers were, unsurprisingly, at a greater risk of dying from heart disease than non-binge drinkers — though they also cautioned that just because they didn’t find correlations between binge drinking and socioeconomics did not mean that this correlation doesn’t exist.

This isn’t the first time that scientists have looked at the links between heart disease and class. Previous studies have found that the more socioeconomic disadvantages experienced, the higher the likelihood of death from heart disease.

One of the implications of this study is the need for health interventions that consider class. As Jurgen Rehm and Charlotte Probst of Canada’s Center for Addiction and Mental Health said of the findings, “it is not appropriate simply to extrapolate from risks associated with alcohol use in higher-income populations to address lower-income populations where the impact of alcohol use is highest.”


Abstract

Background: Socioeconomically disadvantaged groups tend to experience more harm from the same level of exposure to alcohol as advantaged groups. Alcohol has multiple biological effects on the cardiovascular system, both potentially harmful and protective. We investigated whether the diverging relationships between alcohol drinking patterns and cardiovascular disease (CVD) mortality differed by life course socioeconomic position (SEP).

Methods:

From 3 cohorts (the Counties Studies, the Cohort of Norway, and the Age 40 Program, 1987± 2003) containing data from population-based cardiovascular health surveys in Norway, we included participants with self-reported information on alcohol consumption frequency (n = 207,394) and binge drinking episodes (5 units per occasion, n = 32,616). We also used data from national registries obtained by linkage. Hazard ratio (HR) with 95% confidence intervals (CIs) for CVD mortality was estimated using Cox models, including alcohol, life course SEP, age, gender, smoking, physical activity, body mass index (BMI), systolic blood pressure, heart rate, triglycerides, diabetes, history of CVD, and family history of coronary heart disease (CHD). Analyses were performed in the overall sample and stratified by high, middle, and low strata of life course SEP. A total of 8,435 CVD deaths occurred during the mean 17 years of follow-up. Compared to infrequent consumption (2±3 times per week) was associated with a lower risk of CVD mortality (HR = 0.78, 95% CI 0.72, 0.84) overall. HRs for the high, middle, and low strata of SEP were 0.66 (95% CI 0.58, 0.76), 0.87 (95% CI 0.78, 0.97), and 0.79 (95% CI 0.64, 0.98), respectively, compared with infrequent users in each stratum. HRs for effect modification were 1.30 (95% CI 1.10, 1.54, p = 0.002; middle versus high), 1.23 (95% CI 0.96, 1.58, p = 0.10; low versus high), and 0.96 (95% CI 0.76, 1.21, p = 0.73; low versus middle). In the group with data on binge drinking, 2,284 deaths (15 years) from CVDs occurred. In comparison to consumers who did not binge during the past year, HRs among frequent bingers (1 time per week) were 1.58 (95% CI 1.31, 1.91) overall, and 1.22 (95% CI 0.84, 1.76), 1.71 (95% CI 1.31, 2.23), and 1.85 (95% CI 1.16, 2.94) in the strata, respectively. HRs for effect modification were 1.36 (95% CI 0.87, 2.13, p = 0.18; middle versus high), 1.63 (95% CI 0.92, 2.91, p = 0.10; low versus high), and 1.32 (95% CI 0.79, 2.20, p = 0.29; low versus middle). A limitation of this study was the use of a single measurement to reflect lifetime alcohol consumption.and 0.96 (95% CI 0.76, 1.21, p = 0.73; low versus middle).

Results: Moderately frequent consumers had a lower risk of CVD mortality compared with infrequent consumers, and we observed that this association was more pronounced among participants with higher SEP throughout their life course. Frequent binge drinking was associated with a higher risk of CVD mortality, but it was more uncertain whether the risk differed by life course SEP. It is unclear if these findings reflect differential confounding of alcohol consumption with health-protective or damaging exposures, or differing effects of alcohol on health across socioeconomic groups.