Stroke is the second leading cause of death worldwide and accounts for around 11%Trusted Source of deaths each year, according to the World Health Organization (WHO).
What’s more, the World Stroke Organization (WSO) estimates that stroke incidence increased by 70%Trusted Source between 1990 and 2019, and deaths from stroke increased by 43% in the period.
Stroke survivors experience physical disabilitiesTrusted Source and cognitive impairments that often limit their economic activities for the rest of their lives.
While stroke mostly impacts those over 44 years old, increasing numbers of younger adults are experiencing stroke. The WSO estimated that around 8%Trusted Source of the 13.7 million strokes each year occur in adults under 44 years of age.
But more than 90%Trusted Source of stroke cases are linked to modifiable risk factors such as alcohol consumption, which has been increasing globally. For instance, alcohol consumption increased by 104% per capita in East Asia between 1990 and 2017. Research from 2019Trusted Source shows that global alcohol consumption is projected to increase substantially.
While heavy alcohol consumption is linked to stroke risk, little is known about the effects of moderate drinking on stroke risk over time.
In a new study, researchers investigated the effects of cumulative alcohol consumption on adults ages 20 to 39 years old in South Korea.
They found that young adults who engaged in moderate to heavy drinking were at a higher risk of stroke.
The study was recently published in Neurology.
Effects of alcohol consumption on stroke risk
For the study, the researchers examined national health record data from 1,536,668 men and women.
Participants ranged in age from 20 to 39 years old and underwent four annual health examinations between 2009 and 2012. Stroke risk was the primary health outcome among subjects.
The researchers split alcohol consumption into four categories measured by alcohol consumption in grams per week:
- mild drinking: 0-105 g
- moderate drinking: 105-210 g
- heavy drinking: over 210 g
For reference, 105 grams of alcohol is equivalentTrusted Source to 7 and a half 12-ounce beers or one-and-a-half standard bottles of wine.
Additionally, researchers examined subjects’ age, sex, and income, alongside comorbidities such as hypertension, diabetes, and cancer.
Participants were followed for an average of 5.6 years. During the follow-up period, 3,153 people experienced a stroke.
After analyzing the data, the researchers noted that stroke incidence steadily increased alongside cumulative alcohol consumption.
Subjects with 2 years of moderate to heavy drinking were at a 19% higher risk of stroke. Meanwhile, those with 3 years had a 22% increased risk, and those with 4 years had a 23% higher risk.
Researchers also found that heavy drinkers had a 28% higher stroke risk than non-drinkers, although the risk for mild to moderate drinkers was not statistically significant.
The researchers concluded that reducing alcohol consumption should be emphasized for young adults with heavy drinking as a stroke prevention strategy.
Dr. John Mendelson, a board certified internist and chief medical officer of Ria Health, not involved in the study, noted to MNT:
“Stroke is exceedingly uncommon in young people, and hemorrhagic strokes are even rarer. Hemorrhagic strokes usually occur in people during spikes of extremely high blood pressure or in patients on anticoagulants.”
Why is alcohol consumption linked to stroke risk?
To understand how drinking is linked to stroke risk, Medical News Today spoke with Tamar Rodney, Ph.D., RN, assistant professor at the Johns Hopkins School of Nursing, who was not involved in the study.
“Alcohol affects multiple body organs primarily because it is carried throughout the body via [the] blood,” Dr. Rodney said.
“The way the body processes alcohol means that it will affect multiple organs very quickly, which includes the brain.”
“Repeated occurrences of alcohol to the brain can trigger events that lead to lack of oxygenated blood flow or clots in the brain, which can cause a stroke. The brain, however, is just one of many organs that can dysfunction [due to] excessive alcohol intake.”
– Tamar Rodney, Ph.D., RN, assistant professor of nursing
Debbie Fetter, Ph.D., assistant professor of teaching nutrition at the University of California, Davis, not involved in the study, told MNT:
“Alcohol is an example of an empty calorie source. [It] provides almost no nutritional value [and is] just an energy source at 7 kcals [per] gram. [It] has also been recognized as a carcinogen since 1988 — ethanol in alcohol is classified as a group 1 carcinogen.”
“Although people consume alcohol for a variety of reasons, from a health viewpoint, it’s recommended to the public to limit or refrain,” Dr. Fetter added.