Alcohol intake may lower stress-related brain activity, helping the heart
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Key takeaways:
- Light to moderate alcohol consumption associates with significant reductions in major adverse CV event risk, mediated by neural activity.
- The researchers said there is no safe amount of alcohol consumption.
Compared with no or little alcohol intake, consuming one to 14 drinks per week is associated with lower risk for major adverse CV events, likely due to an alcohol-mediated reduction in stress-associated brain activity, researchers reported.
In an analysis of biobank and brain imaging data that included more than 50,000 participants, researchers also said there is no recommended “safe” amount of alcohol consumption and that any risks outweigh a possible heart benefit. The findings, published in the Journal of the American College of Cardiology, were first presented at the 2021 American College of Cardiology Scientific Session and reported by Healio.
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“We have known that alcohol has been associated with a reduction in CVD, at least at light to moderate consumption,” Ahmed Tawakol, MD, director of nuclear cardiology and co-director of the Cardiovascular Imaging Research Center at Massachusetts General Hospital, told Healio. “There has been a question as to the mechanism and as to whether those potential effects persist after adjustment for confounders. We also recognize that alcohol acutely reduces stress. We wanted to know: Could alcohol impact the stress systems chronically, and if so, could that be a mechanism by which it might reduce CVD risk?”
Assessing alcohol intake, brain imaging data
For the analysis of the relationship between alcohol consumption and major adverse CV events, the researchers included 53,064 participants from the Mass General Brigham Biobank, established in 2010, who completed an optional health survey with information on alcohol consumption during the year before enrollment. The median age of participants was 60 years and 60% were women. Researchers classified alcohol consumption for both men and women as non/minimal, defined as less than one drink per week; light/moderate, defined as one to 14 drinks per week; and high, defined as more than 14 drinks per week.
For the analysis of the effect of stress neurobiology, the researchers included 713 participants who underwent 18F-fluorodeoxyglucose PET/CT brain imaging to assess the balance between pro-stress and regulatory signals.
Within the cohort, 23,920 were minimal drinkers; 27,053 were light/moderate drinkers and 2,091 participants were heavy drinkers. During median follow-up of 3.4 years, 1,914 participants experienced a major adverse CV event.
Compared with no or little alcohol intake (< 1 drink per week), moderate alcohol intake (1-14 drinks per week) was associated with reduced risk for major adverse CV events after adjustment for demographic factors, CVD risk factors, health behaviors, socioeconomic factors and psychological factors (OR = 0.786; 95% CI, 0.717-0.862; P < .0001).
“In this biobank cohort, we were able to adjust for many confounders, including other lifestyle approaches, socioeconomic factors and even genetic factors,” Tawakol said in an interview. “We still saw that there was this substantial relative risk reduction with light to moderate alcohol intake.”
In the imaging cohort, after adjustment for age and sex, moderate alcohol consumption was associated with less stress-associated neural activity compared with little/no or heavy alcohol consumption (standardized beta, –0.192; 95% CI, –0.338 to –0.046; P = .01).
When the researchers conducted a mediation analysis, they demonstrated that stress-associated neural activity significantly mediated the beneficial impact of alcohol on CV clinical events in the cohort.
“As an extension of this finding, we observed that alcohol associates with greater effects on CVD risk reduction among individuals with a history of anxiety in the overall study population,” the researchers wrote. “These findings yield insights into mechanisms by which alcohol may improve major adverse CV event risk and suggest that interventions targeting stress-associated neural networks may improve CVD outcomes.”
Potential adverse effects with drinking
The researchers said despite the findings that light to moderate alcohol consumption may improve CV risk, this benefit must be carefully weighed against its potential adverse impacts on other noncardiac disease processes, such as malignancy, dependence and alcohol abuse.
Compared with little or no alcohol intake, light to moderate drinking was associated with a 23% increased risk for cancer during follow-up, with an HR of 1.23 (95% CI, 1.14-1.33; P < .0001).
“At the same quantities of alcohol that was saw a relative risk reduction in CVD, we saw an increase in cancer,” Tawakol told Healio. “While we identified what might be an important mechanism by which alcohol might introduce benefits for CV health, alcohol’s overall impact on health is not positive. There is no safe quantity of alcohol. What we would like to do is further focus on this pathway of the stress neural networks and identify better approaches that more safely reduce those signals and enhance and improve CV health without the detriments of alcohol.”
Many lifestyle behaviors can have an impact on CV health that is equal to or greater than the benefit observed with light to moderate drinking, Tawakol said. These include exercise, healthy sleep and stress reduction approaches.
“Could we find other therapeutic approaches to modulate those same pathways in a way that leads to CV benefits?” Tawakol said. “More research is needed for that.”
Alcohol ‘moderation is key’
In a related editorial, Giovanni de Gaetano, MD, PhD, from the department of epidemiology and prevention at the IRCCS Istituto Neurologico Mediterraneo Neuromed in Pozzilli, Italy, and colleagues wrote that several studies have observed that moderate alcohol consumption is associated with a lower risk for cognitive decline and dementia, better cognitive function and reduced brain atrophy, suggesting that alcohol may play a protective role in brain function by promoting neural plasticity.
“Although the mechanisms underlying these neuroprotective effects are not fully understood, they may be related to the antioxidant and anti-inflammatory properties of certain compounds found in alcoholic beverages, especially in wine, such as resveratrol and flavonoids,” de Gaetano and colleagues wrote. “These compounds have been shown, in experimental systems, to protect against oxidative stress and inflammation, which can contribute to neuronal damage and cognitive decline. However, it is important to underline that excessive or irregular (binge) alcohol consumption has detrimental effects on brain health and increases the risk of cognitive impairment and dementia. As such, moderation is the key when discussing about alcohol consumption and health.”
References:
- de Gaetano G, et al. J Am Coll Cardiol. 2023;doi:10.1016/j.jacc.2023.04.018.
- Mezue K, et al. Highlighted original research: Prevention and health promotion and the year in review. Presented at: American College of Cardiology Scientific Session; May 15-17, 2021 (virtual meeting).
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