Alcohol consumption, especially binge drinking and drinking excessively over time, is well-understood to heighten risk of damage to multiple organs, including the heart.
Researchers now also have probed alcohol’s impact on one of the precursors to cardiovascular disease: arterial stiffening. While the results show strong associations with excessive consumption, they often find a J-shaped relationship, implying that low-to-moderate alcohol consumption may not be as harmful to arterial health.
Mariann R. Piano, Ph.D., the Nancy and Hilliard Travis Professor of Nursing and senior associate dean for research at Vanderbilt University Medical Center, is senior author on an integrative review that examines the literature on arterial stiffening and alcohol consumption in adults. Her team’s work was published in Cardiovascular Toxicology in February of 2022.
“We knew the relationships were there, but a review of various studies allows us to draw more conclusions to support recommendations to clinicians and patients,” Piano said.
Measuring Arterial Stiffness
Arterial stiffness reflects the gradual fragmentation and loss of elastin fibers in the artery walls and their replacement with stiffer collagen fibers. Hypertension and coronary artery disease are common consequences of this mechanism playing out over years.
In the human body, the large arteries leaving the heart have the most elastin, and the distal arterioles have more collagen, creating an impedance mismatch that is a measurable way to determine overall arterial stiffness. Pulse wave velocity (PWV) measures this mismatch non-invasively using several types of devices.
Equivocal Findings on Impact
When Piano and her team examined the literature on alcohol and arterial stiffening, they found a preponderance of evidence that binge drinking as well as heavy drinking is associated with arterial stiffness in men. Some studies showed a linear relationship, but more often the results produced a J-shaped curve. Piano said only a few studies found a significant impact on the arteries of women, and some studies found no association in either men or women.
Interestingly, one large study found that blood pressure levels may influence whether drinkers have significant changes in arterial stiffness. They found a U-shaped relationship in individuals with normal blood pressure, while patients with higher blood pressure had a steeper, more linear relationship.
Binging Leads to the Most Stiffening
Binge drinking is typically defined as four drinks or more for women or five for men, on the same occasion or within two hours in one day.
A large study of young adults found that binge drinking as well as increased drinking intensity, at the rate of 10 or more drinks per typical drinking day, were correlated significantly with increased arterial stiffness compared to subjects with an alcohol intake of less than two drinks on a typical day.
“Taken together, we can say that, at least in men, the risk of arterial stiffening begins to increase as alcohol consumption exceeds eight drinks per week or more than one drink per day,” Piano said. “It also seems that there is something about the event of binge drinking – the high volume over a short period of time – that is a particular insult to the arterial walls.”
Potential Mechanisms for Stiffening
The mechanisms underlying the association between alcohol use and arterial stiffness remain unknown. Hypotheses center on flavonoids and the effects of alcohol use on the ratio between triglycerides and high-density lipoprotein cholesterol. Piano says excessive production of reactive oxygen species on endothelial function also plays a key role in alcohol-induced vascular damage.
The effect of norepinephrine, which is stimulated by repeated binge drinking, is suspected to play a role. Alcohol is also implicated in arterial calcification and inflammation that hasten stiffening.
“In men, the risk of arterial stiffening begins to increase as alcohol consumption exceeds eight drinks per week or more than one drink per day. It also seems that there is something about the event of binge drinking – the high volume over a short period of time – that is a particular insult to the arterial walls.”
“While we think each of these factors play a part, what we are seeing is their downstream effect of inducing matrix metalloproteinase-9 (MMP-9),” Piano said. “Heavier drinkers have higher serum MMP-9, increasing the degradation of elastin and causing structural changes in the arterial wall.”
With 70 percent of American adults consuming alcohol and a quarter reporting binge drinking, Piano hopes clinicians will promote pulse wave velocity testing for their patients who are heavy or binge drinkers.
“Although no exact reference value has been established, findings from numerous studies suggest arterial stiffness values greater than 10 m/s are associated with greater risk,” Piano said.
“Alcohol use screening is important since patients can make changes to prevent or reduce their cardiovascular risk.”