If you drink more than the recommended guidelines for low-risk alcohol consumption, you are not only placing yourself at risk for developing an alcohol use disorder, but you are also significantly increasing your risk of a variety of cardiovascular problems.
There is a massive amount of scientific research that indicates an increased risk for heart problems for people who drink alcohol habitually or heavily. Based on that research, the National Institute on Alcohol Abuse and Alcoholism (NIAAA) has established guidelines for “safe” drinking levels and “high risk” drinking.
Here are the exact levels of alcohol consumption that the NIAAA deems “low risk:”
- For men, 4 or fewer drinks per day, and less than 14 drinks per week
- For women, 3 or fewer drinks per day, and no more than 7 drinks per week
For example, if you are male and drink a 12-pack of beer during the week and then drink a 6-pack during the weekend, you are exceeding the recommended guidelines by 4 drinks. If you are female and drink 2 glasses of wine every day, you are drinking twice the amount recommended as safe.
If you exceed the above daily guidelines, you are considered a binge drinker. If you exceed the weekly guidelines you would be engaged in heavy alcohol consumption. Both binge drinking and heavy drinking have their own short- and long-term health risks.
The Risk of an Immediate Cardiac Event
Even if you drink within the “low risk” guidelines, it does not mean there is no risk at all. Drinking any amount of alcohol at all can increase the risk of having an immediate cardiovascular event within the next 24 hours.
Many studies have been conducted regarding the cardiovascular effects of moderate and heavy alcohol consumption both in the short and long term. An analysis of 23 studies involving 29,457 participants was conducted by Mosotofsky and colleagues to determine the physiological effects of both moderate and heavy drinking on those risks.
The investigators examined the relationship between alcohol intake and:
- Myocardial infarction
- Ischemic stroke
- Hemorrhagic stroke
In a study published in the journal Circulation, the researchers concluded that any alcohol consumption increases the risk of a cardiovascular event within the first 24 hours, but only heavy alcohol intake continued the risk for up to a week.
In fact, the study indicated that moderate alcohol intake may have a protective effect for up to a week. Moderate drinkers (2-4 drinks) were 30 percent less likely to have a myocardial infarction or hemorrhagic stroke within a week, and 19 percent less likely to have an ischemic stroke, compared with nondrinkers.
Heavy drinkers, on the other hand, were more than twice as likely to have a cardiovascular event with 24 hours (6-9 drinks) and up to six times more likely within a week (19-30 drinks).
Alcohol and the Risk of Mortality
Another analysis of 84 research studies examined the effect of alcohol consumption on the following cardiovascular outcomes:
- Overall mortality from cardiovascular disease
- Incidence and mortality from coronary heart disease, and
- Incidence and mortality from stroke
The analysis, led by P.E. Ronksley and associates, found that light to moderate alcohol consumption was linked to a reduced risk of multiple cardiovascular outcomes, but the protective level for those outcomes is associated with a level of drinking even lower than the NIAAA guidelines.
The dose-response analysis indicated that the lowest risk for coronary heart disease mortality occurred with 1-2 drinks per day and for stroke mortality, it occurred with exactly 1 drink per day, compared with nondrinkers.
Therefore, Ronksley’s analysis could be interpreted to show that any drinking above two drinks per day increases the risk of death by coronary heart disease and any level of alcohol consumption above one drink per day could increase the risk of death by stroke, compared with nondrinkers.
Higher Risk for Women Drinkers
Others investigators conducted an analysis of 23 research studies involving 489,686 participants to see if the link between alcohol intake and major cardiovascular outcomes, as well as total mortality, was greater for women compared to men.
The analysis, led by YL Zheng and colleagues, compared moderate to heavy drinking to the lowest alcohol intake or nondrinkers in women and men.
The researchers concluded that moderate to heavy female drinkers had a significantly increased risk of total mortality compared with men.
Significantly, the study revealed that there was no difference in the risk for major cardiovascular outcomes or total mortality between women and men heavy drinkers or nondrinkers.
The largest risk increase occurred between female binge drinkers and male light drinkers, the researchers found.
The researchers recommended that young women, particularly those susceptible to binge drinking, consider controlling their alcohol intake.
Moderate Drinking and Heart Failure
Another analysis of eight research studies that involved 202,378 participants examined the risk of heart failure for the following levels of alcohol consumption:
- 3 drinks per week
- 7 drinks per week
- 10 drinks per week
- 14 drinks per week
- 21 drinks per week
For all levels of alcohol consumption under 14 drinks per week, the investigators reported a “non-linear relationship” between alcohol consumption and the risk of heart failure.
However, for 14 drinks a week, the relative risk of heart failure among participants began to range up to 10 percent higher than nondrinkers and for 21 drinks per week began to range up to 48 percent higher.
The study concluded that moderate alcohol consumption is linked to a reduced risk of heart failure, but that means less than 2 drinks a day.
Alcohol Consumption and Atrial Fibrillation
Alcohol consumption has long been associated with an increased risk of atrial fibrillation, but few studies have been done on the effect of light to moderate drinking on the condition.
A study of 79,019 men and women over an 11-year period and an analysis of seven research studies involving another 12,554 participants examined the effect of alcohol consumption ranging from one drink per week to 21 drinks per week on the incidence of atrial fibrillation.
S.C. Larrson and associates did find a linear relationship between alcohol consumption and the risk of atrial fibrillation. As the number of drinks per week increased, the relative risk of developing atrial fibrillation increased.
Compared to nondrinkers, the study found the following percentages of increased risk for atrial fibrillation at these levels of alcohol consumption:
- one drink per day, 8 percent
- two drinks per day, 17 percent
- three drinks per day, 26 percent
- four drinks per day, 36 percent
- five drinks per day, 47 percent
The investigators concluded that alcohol consumption, even at moderate levels, is a risk factor for atrial fibrillation.
Moderate Drinking and Other Risks Factors
The above risk factors for drinking at higher levels that the recommended guidelines concern cardiovascular problems only. There are many other health conditions that can be affected by alcohol consumption.