We asked brewing expert Charles Bamforth, Ph.D., about the folklore surrounding Guinness beer.

Lauren Wicks; Nutrition review by Lisa Valente, M.S., R.D.
March 13, 2020
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Old Guinness beer advertisement
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Guinness is an iconic Irish beer known for its velvety mouthfeel and richness. It's also known for several touted health benefits, like its iron content and being good for your heart. We wanted to know if Guinness actually had any health benefits, or if drinking it just gave you the luck of the Irish.

We reached out to Charles Bamforth, Ph.D. Distinguished Professor Emeritus, UC Davis, to learn more about Guinness and its supposed health benefits. Bamforth is a 42-year veteran of the brewing industry in the U.S. and U.K. and the author of more than a dozen books on beer.

How Did People Start to Believe Guinness Is Healthy?

"There was a time in the middle of the 20th century where Guinness was advertised on a slogan of 'Guinness Is Good for You,'" Bamforth says. "Otherwise, it somehow developed as a word of mouth thing."

This slogan came about based on market research that people felt good after drinking a pint of the beer, according to Smithsonian Magazine. Guinness also contains iron, and pregnant women were even advised to drink it occasionally to boost their intake during the first half of the 20th century.

Is There Any Research to Back Up the Touted Health Benefits of Guinness?

Bamforth says there are plenty of nutritional benefits in most beers, including antioxidants, B vitamins, fiber, silicon and prebiotics. He says Guinness is one of the richer sources of these nutrients.

A large review of studies published in the European Journal of Clinical Nutrition sought to test persisting myths regarding the health benefits of beer and found it could be as beneficial for your heart as red wine, and its ethanol and silicon content could bolster bone health. And since beer is made with barley—a whole grain—it contributes some antioxidants (heart-healthy polyphenols), B vitamins, fiber and prebiotics to your beverage. The polyphenols from barley and hops show to lower cholesterol, reduce your risk for heart disease and protect against free radicals.

When it comes to Guinness specifically, researchers from the University of Wisconsin found drinking Guinness offered more protective effects against heart conditions than lagers. The researchers believe the extra antioxidant compounds could be the reason for this, but this research was preliminary and warrants further study. Bamforth says it's likely the alcohol in any beverage—not just Guinness—that can protect against atherosclerosis. There has been no research published in a peer-reviewed scientific journal regarding Guinness and health.

Any recommendation for pregnant women to drink an occasional Guinness was severely misguided. You would need to drink a whole lot of Guinness to get a day's worth of iron—and you're better off getting your calories from other iron-rich sources, like spinach and oysters. The CDC says there is no safe amount of alcohol to drink during pregnancy, and all types of alcohol are equally harmful for fetal development.

Is Guinness Really Lower in Calories Than the Average Beer?

Guinness is also lower in calories than the average beer, even though it has a richer mouthfeel and fills you up. Bamworth says Guinness is 4.3% ABV, whereas most popular lager beers in the U.S. are at least 5%. Alcohol is the main source of calories in any alcoholic beverage, so a Guinness will naturally be lower in calories than a Budweiser containing 5% alcohol—even though it might seem more filling.

The makers of Guinness use a process called nitrogenisation, which pairs nitrogen gas and carbon dioxide to give the beer its iconic velvety texture. This is similar to how drinking nitro cold brew is silkier than a regular cup of cold brew coffee, making it seem more filling without adding any extra calories.

The Bottom Line

There is plenty of contradicting research out there regarding alcohol consumption and health, as one review of studies published in American Journal of Public Health found moderate alcohol consumption reduced cardiovascular disease risk, but increased the risk for breast cancer. Some research finds those who drink alcohol in moderation actually live longer than their teetotalling counterparts, while other bodies of research argue no amount of alcohol is safe to consume. It's important to note Guinness does not make any health claims about its beer.

Most health organizations say that moderate alcohol consumption—one drink a day for women and two for men—is safe. However, these organizations also advise not to start drinking alcohol if you currently abstain. It's safe to say that light to moderate drinking likely won't harm your health, but you shouldn't imbibe for the sake of longevity.