Alcohol: Are happy hours good for your heart?

04/21/25 • 65 min

Normal Curves: Sexy Science, Serious Statistics

Does a daily glass of wine really keep the cardiologist away? It’s a claim we’ve all heard: light to moderate drinking is good for your heart. But is it science or just a convenient excuse for happy hour? In this episode, we dive into the history behind this claim, discuss the challenges of observational studies and statistical adjustment, and explore attempts at randomized trials and natural experiments to get to the bottom of this boozy debate. Grab your drink—or maybe don’t—and join us!

Statistical topics

Statistical Adjustment
Regression
Residual and Unmeasured Confounding
Randomized Trials
Multiple Testing
Outcome Switching
Mendelian Randomization

Methodological morals
“Statistical adjustment cannot erase all confounding.”

“When you can’t experiment on people, let Nature experiment on people.”

Citations

Alcohol and Drinking. Gallup Poll. 2024.
Canada’s Guidance on Alcohol and Health. Canadian Centre on Substance Use and Addiction. 2023.
U.S. Department of Agriculture and U.S. Department of Health and Human Services. 2020 – 2025 Dietary Guidelines for Americans. 2020.
U.S. Department of Agriculture and U.S. Department of Health and Human Services. Alcohol and Cancer Risk: The US Surgeon General's Advisory. 2025.
Mezue K, Osborne MT, Abohashem S, et al. Reduced stress-related neural network activity mediates the effect of alcohol on cardiovascular risk. JACC. 2023;81:2315-25.
McPhillips D, Goodman B. Small amounts of alcohol may turn down stress in the brain, benefiting the heart, new study finds. CNN. June 12, 2023.
Friedman GD, Klatsky AL. Is alcohol good for your health? NEJM. 1993;329:1882-3.
Sainani K. Alcohol and Weight. Allure. July 14, 2010.
Wang LU, Lee IM, Manson JE, et al. Alcohol consumption, weight gain, and risk of becoming overweight in middle-aged and older women. Arch Intern Med. 2010;170:453-61.
Sainani K. Drinking and Weight. Allure. Oct 31, 2008.
Tolstrup JS, Halkjær J, Heitmann BL, et al. Alcohol drinking frequency in relation to subsequent changes in waist circumference. Am J Clin Nutr. 2008;87:957-63.
Rabin RC. Major Study on Drinking Will be Shut Down. New York Times. June 15, 2018.
Mitchell G, Lesch M, McCambridge J. Alcohol industry involvement in the moderate alcohol and cardiovascular health trial. AJPH. 2020;110:485-8.
Gepner Y, Golan R, Harman-Boehm I, et al. Effects of Initiating Moderate Alcohol Intake on Cardiometabolic Risk in Adults With Type 2 Diabetes: A 2-Year Randomized, Controlled Trial. Ann Intern Med. 2015;163:569-79.
Slade E, Drysdale H, Goldacre B, et al. Discrepancies between prespecified and reported outcomes. Ann Intern Med. 2016;164:374.
Biddinger KJ, Emdin CA, Haas ME, et al. Association of habitual alcohol intake with risk of cardiovascular disease. JAMA Netw Open. 2022;5:e223849.

Page with more details on the CASCADE trial

Kristin and Regina’s online courses:

Statistical topics

Statistical Adjustment
Regression
Residual and Unmeasured Confounding
Randomized Trials
Multiple Testing
Outcome Switching
Mendelian Randomization

Methodological morals
“Statistical adjustment cannot erase all confounding.”

“When you can’t experiment on people, let Nature experiment on people.”

Citations

Alcohol and Drinking. Gallup Poll. 2024.
Canada’s Guidance on Alcohol and Health. Canadian Centre on Substance Use and Addiction. 2023.
U.S. Department of Agriculture and U.S. Department of Health and Human Services. 2020 – 2025 Dietary Guidelines for Americans. 2020.
U.S. Department of Agriculture and U.S. Department of Health and Human Services. Alcohol and Cancer Risk: The US Surgeon General's Advisory. 2025.
Mezue K, Osborne MT, Abohashem S, et al. Reduced stress-related neural network activity mediates the effect of alcohol on cardiovascular risk. JACC. 2023;81:2315-25.
McPhillips D, Goodman B. Small amounts of alcohol may turn down stress in the brain, benefiting the heart, new study finds. CNN. June 12, 2023.
Friedman GD, Klatsky AL. Is alcohol good for your health? NEJM. 1993;329:1882-3.
Sainani K. Alcohol and Weight. Allure. July 14, 2010.
Wang LU, Lee IM, Manson JE, et al. Alcohol consumption, weight gain, and risk of becoming overweight in middle-aged and older women. Arch Intern Med. 2010;170:453-61.
Sainani K. Drinking and Weight. Allure. Oct 31, 2008.
Tolstrup JS, Halkjær J, Heitmann BL, et al. Alcohol drinking frequency in relation to subsequent changes in waist circumference. Am J Clin Nutr. 2008;87:957-63.
Rabin RC. Major Study on Drinking Will be Shut Down. New York Times. June 15, 2018.
Mitchell G, Lesch M, McCambridge J. Alcohol industry involvement in the moderate alcohol and cardiovascular health trial. AJPH. 2020;110:485-8.
Gepner Y, Golan R, Harman-Boehm I, et al. Effects of Initiating Moderate Alcohol Intake on Cardiometabolic Risk in Adults With Type 2 Diabetes: A 2-Year Randomized, Controlled Trial. Ann Intern Med. 2015;163:569-79.
Slade E, Drysdale H, Goldacre B, et al. Discrepancies between prespecified and reported outcomes. Ann Intern Med. 2016;164:374.
Biddinger KJ, Emdin CA, Haas ME, et al. Association of habitual alcohol intake with risk of cardiovascular disease. JAMA Netw Open. 2022;5:e223849.

Page with more details on the CASCADE trial

Kristin and Regina’s online courses:

Previous Episode

The Red Dress Effect: Are women in red sexier?

Wear red and drive men wild with lust – or so says scientific research on color’s role in human mating. But can a simple color swap really boost a woman’s hotness score? In this episode, we delve into the evidence behind the Red Dress Effect, from a controversial first study in college men to what the latest research says about who this trick might work for (and who it might not). Along the way we encounter red monkey butts, old-Internet websites, the Winner’s Curse in scientific research, adversarial collaborations, and why size (ahem, sample size) really does matter.

Statistical topics

Reproducibility crisis in psychology
Sample size
Selection bias
Winner’s curse
Cohen’s d standardized effect size
Adversarial collaboration
Meta-analysis
Preregistration
Publication bias
Statistical moderators

Methodological morals

“The smaller the sample, the flashier the result, the less you should trust it.”

“Good scientists learn from their statistical mistakes and fix them.”

References

Clarke, G. How to Be Sexy: 7 Weird (But True) Rules of Attraction. Allure. January 23, 2013.
Nuzzo, R. Vying for a soul mate? Psych out the competition with science. Los Angeles Times. December 8, 2008.
Vying for a Soul Mate on the Today Show, December 30, 2008.
Elliot, A.J. and Niesta, D. Romantic red: red enhances men's attraction to women. Journal of personality and social psychology. 2008; 95: 1150 – 1164.
Lehrer, J. The Truth Wears Off. The New Yorker , December 5, 2010.
MacMahon, B., Yen, S., Trichopoulos, D., Warren, K. and Nardi, G. Coffee and cancer of the pancreas. New England Journal of Medicine. 1981; 304: 630-633.
Ioannidis, J.P. Why most published research findings are false. PLoS medicine. 2005; 2(8), e124
Lehmann, G.K., Elliot, A.J. and Calin-Jageman, R.J. Meta-analysis of the effect of red on perceived attractiveness. Evolutionary Psychology. 2018; 16: 1474704918802412.
Pazda, A.D., Thorstenson, C.A. and Elliot, A.J. The effect of red on attractiveness for highly attractive women. Curr Psychol. 2023; 42: 8066–8073

Kristin and Regina’s online courses:

Demystifying Data: A Modern Approach to Statistical Understanding

Clinical Trials: Design, Strategy, and Analysis

Medical Statistics Certificate Program

Writing in the Sciences

Epidemiology and Clinical Research Graduate Certificate Program

Chapters

(00:00) - Introduction
(06:04) - Red Dress Effect on TV
(10:01) - Red Monkey Butts
(12:56) - 2008 Study on Romantic Red
(16:04) - HotOrNot.com
(20:10) - 2008 Study Results
(25:10) - Cohen’s d Standardized Effect Size
(30:52) - Problems with Small Sample Sizes
(34:12) - Winner’s Curse and Publication Bias
(38:40) - Reproducibility Crisis
(44:03) - Adversarial Collaboration
(49:01) - Meta-Analysis and Pre-Registration
(55:23) - Adversarial Discussion Sections and Updates
(01:02:55) - Latest Red Study
(01:06:26) - Wrap-Up

Next Episode

Hookworms: Can parasites improve your health?

What if you could treat your prediabetes with . . . worms? Regina and Kristin dive into a surprising early-phase clinical trial on hookworm therapy—that’s right, intentionally infecting yourself with parasitic worms—to treat metabolic conditions. They dig into the biological rationale (inflammation, abdominal fat, and gut immunology), the clever study design (hello, Tabasco sauce!), and the statistical chops behind this phase 1B trial (block randomization, missing data, and nonparametric hypothesis tests). Along the way, expect self-experimenting scientists, worm sex, poop analysis, and the world’s nerdiest aphrodisiac: a well-documented protocol.

Statistical topics

Randomized controlled trial (RCT)
Primary and secondary outcomes
Placebos, placebo effect, and nocebo effect
Block randomization
Sample size
Double-blinding
Missing data protocols
Reproducible research
Nonparametric hypothesis testing
Kruskal-Wallis test

Methodological morals

“Walk before you can run. Invest in simple but high-quality Phase I clinical trials.”
“When faced with small samples, you better rank and sum, baby.”

References