Long-term drinking patterns: Impact on heart disease and mortality
The question of the health effects of consuming alcoholic beverages remains a topic of ongoing interest, as there are still many specific issues that need to be clarified.
There is little known about how drinking patterns change over the years and how this affects cardiovascular health and overall mortality. A team of U.S. researchers focused on precisely this question. They used data from one of the most famous cohort studies, the Framingham Study, which has been ongoing since 1948 in Framingham, Massachusetts. Participants were examined approximately every four years and surveyed about their lifestyle habits, including their drinking habits.
More specifically, two study groups were examined: 2,790 individuals from the original Framingham group (beginning in 1971), as well as 3,780 individuals from the Framingham Offspring Cohort, which studied the “next generation” of participants (starting in 1979). The participants in the second group were about 20 years younger, had a significantly healthier lifestyles, and grew up in greater prosperity and with higher levels of education. In both generations, the gender distribution was balanced, with 59.7 percent men and 52.1 percent women. This allowed for a separate analysis of men and women.
The first phase of the study, which lasted over 15 years, served to regularly survey drinking habits and describe changes over time. The second phase of the study lasted 10 years. During this period, data were collected on the incidence of heart attacks and the mortality thereof and other cardiovascular diseases, as well as on overall mortality.
Four long-term drinking patterns were identified in both cohorts and for both genders:
- Moderate-decreasing group: At the start, consumption of alcoholic beverages was a maximum of 14 g/day for women and a maximum of 28 g/day for men, which is classified as moderate. Over time, consumption levels declined.
- Upward and downward group: They showed variable intake over time, consumption increased in the early years, then decreased again, with men remaining at a higher level than women.
- Low to abstinent group: Women in this group consumed virtually no alcoholic beverages; among men, low consumption (< 14 g/day) continued to decline over time.
- High-decreasing group: Women consumed an average of more than 14 g/day, while men consumed between 45 and 60 g/day.
Moderate-decreasing consumption with the lowest risks
When long-term drinking habits were correlated with the risk of death and the risk of cardiovascular events, the following picture emerged after accounting for various confounding factors: Compared to women in Group 1 (moderate-declining), all others had a significantly increased risk of death by 24 to 28 percent. The situation was similar for men: Compared to those in Group 1, men in Groups 2 and 4 had a significantly higher risk of death by 17 and 27 percent, respectively. Only Group 3 showed no significant difference.
Regarding the risk of cardiovascular events, a consistent pattern emerged again among women: Compared to women in Group 1, all others had significantly higher risks, ranging from 58 to 61 percent. Among men, however, only participants in Group 3 fared significantly worse than those in Group 1, with a 60 percent increased risk.
The study findings suggest that sustained low to moderate drinking was associated with lower risks of mortality and CHD in both women and men, compared to high-level or fluctuating patterns. Although these associations may not confirm causality, the findings emphasise the importance of investigating long-term drinking patterns in public health. Like all observational studies, there are limitations when it comes to interpreting the data. The authors caution against promoting moderate alcohol consumption as a strategy to reduce mortality risk or prevent CHD and emphasize that they cannot prove that moderate consumption is the cause of lower risks of disease and mortality. However, the data suggest that long-term light to moderate consumption is associated with lower risks.
