Alcohol: Are happy hours good for your heart?

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: 

• 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 

Program that we teach in:

Epidemiology and Clinical Research Graduate Certificate Program 

Find us on:

Kristin -  LinkedIn & Twitter/X

Regina - LinkedIn & ReginaNuzzo.com

• (00:00) - Introduction
  


• (03:00) - Drinking habits in America
  


• (04:13) - New Canadian drinking guidelines
  


• (07:51) - Definition of light-to-moderate drinking
  


• (08:43) - Risks and benefits of light-to-moderate drinking
  


• (11:37) - History of the heart health claim
  


• (18:34) - Problems with observational studies
  


• (22:40) - Statistical adjustment
  


• (25:39) - Residual and unmeasured confounding
  


• (31:19) - Overconfidence in observational studies
  


• (35:16) - Randomized trials of alcohol
  


• (36:32) - Canceled NIH randomized trial of alcohol
  


• (41:42) - The CASCADE randomized trial of wine
  


• (43:18) - The problem of multiple testing
  


• (47:56) - Outcome switching
  


• (49:32) - Mendelian randomization
  


• (59:04) - Mendelian randomization studies of alcohol and heart disease
  


• (01:03:09) - Wrap-up