Drinking patterns and risk of ischemic stroke in middle aged adults: do beneficial drinking habits indeed exist?
Summary by Ashleigh Howe
Research has historically produced conflicting results when it comes to alcohol consumption and stroke risk. Some studies suggest that different types of alcohol have different impacts on stroke risk, while others suggest that light alcohol consumption may even be protective. With 14% of people reporting their alcohol consumption increased over the COVID-19 pandemic, it is more important than ever to explore how this may impact their future stroke risk.
This paper aimed to address the conflicting research through exploring the impact of drinking patterns on ischemic stroke, which is caused by reduced oxygen reaching the brain.
Data was collected from a large existing cohort in Korea, using 152,469 middle aged participants. Participants’ drinking pattern was defined using the frequency of alcohol intake and the amount they drank each time. Five drinking patterns were identified: 1) abstainers who did not drink alcohol; 2) those who drank less than 30g a day less than 5 days a week; 3) those who drank less than 30g a day and more than 5 days a week; 4) those who drank over 30g a day and less than 5 days a week; 5) those who drank more than 30g a day and more than 5 days a week. These figures were collected through a questionnaire. Participants were followed up for an average period of 9 years, providing long term data on their future stroke risk through health insurance details.
Drinker group 4, who were drinking more alcohol in each sitting but less frequently showed lower stroke risk than abstainers. However, drinking less alcohol more frequently as in drinker group 3 did not show a reduced risk in the first 7 years. Nevertheless, any differences in stroke risk had balanced out by the 7 year follow up, suggesting that the findings do not support the idea that low alcohol intake can reduce stroke risk. Even low alcohol consumption is associated with damaging hypertension, which increases ischemic stroke risk, suggesting that only the abstainer group had a long term reduced stroke risk. Conversely, research has linked moderate alcohol intake to blood clot dissolving effects similar to those seen in medication used to dissolve clots in emergency care. Therefore, it is possible that alcohol consumption has a variety of effects on stroke risk, and while harmful effects such as hypertension may be more severe in older age, the protective effects may not be able to counteract the increased risk conferred by general health and age.
This paper concluded that while light drinking may reduce stroke risk, it fails to have a long-term protective effect. As regular alcohol intake is associated with a host of long-term negative effects such as liver damage, it would be unwise to promote light drinking as a form of protection against stroke risk. As any protective effects of alcohol seem to be fleeting during midlife, it may be worth further exploring how alcohol could protect against stroke and whether this could be maintained into later life and serve to reduce stroke risk across the lifespan. Overall, research does not currently support that even low alcohol intake can reduce stroke risk.
This study can be found at: Doi: 10.1161/STROKEAHA.120.032144
Citation: Yang, W., Kang, D.W., Ha, S.Y. and Lee, S.H., 2021. Drinking Patterns and Risk of Ischemic Stroke in Middle-Aged Adults: Do Beneficial Drinking Habits Indeed Exist?. Stroke, 52(1), pp.164-171.