Guinness is Good for You is one of the most famous advertising campaigns in history, but slogans and billboards aside, it seems like there could have been some truth in the suggestion that everyone’s favorite stout does something positive for the body.
In recent years, researchers have accumulated evidence suggesting that certain beers can help improve species diversity in the gut microbiome, something often linked to health benefits. In 2022, a study in the Journal of Agricultural and Food Chemistry followed 22 men who drank just over half a pint of beer every day for four weeks and found that they subsequently had better indicators of gut health.
Now, a review of experiments published in the journal Frontiers in Nutrition has concluded that the various ingredients in beer can have a positive impact on the immune system when they are broken down and fermented in the intestines.
According to Megan Rossi, a nutrition researcher at King’s College London and founder of The Gut Health Doctor, this is due to plant chemicals known as polyphenols, which are found in certain beers and are known to be useful food for the bacteria in the gut. “Bacteria have been shown to digest about 90 percent of polyphenols and convert them into chemicals, which can have anti-inflammatory effects,” she says.
However, Belgian professor Jeroen Raes, who has investigated the possible effects of beer on the microbiome as part of the Flemish Intestinal Flora Project, warns that we still know relatively little and that the alcohol in beer can negate any positive findings.
“My feeling is that if beer has an effect on the intestines, the effect size will be relatively limited,” he says. “And I’m not sure it’s necessarily a beneficial thing.”
But scientists believe emerging research suggests some beers are potentially better for you than others. Here are some gut-friendly recommendations, and some might be left behind the bar.
Gut-friendly beers
1. Guinness
From the 1920s to the 1960s, marketing slogans such as My Goodness, My Guinness and Guinness for Strength firmly established the brand as perhaps the most popular stout in the world.
But while there are no suggestions that Guinness adds muscle mass, it is believed to be rich in certain plant chemicals. “Some polyphenols are particularly high in Guinness,” says Rossi. “We talk about diversity (being good for the gut), and that also applies to drinks. So if you drank a little Guinness one night and a little red wine the next, while staying within the alcohol limit, you’re likely to get a wider range of these polyphenols.
2. Newcastle Brown Ale
“It’s not a health drink, but some of these ales contain more of these beneficial chemicals and also yeast strains that remain in the beer,” says Federica Amati, a medical scientist at Imperial College London. “They are unlikely to live anymore, but it is thought that they still have a beneficial impact on our immune system when they reach the intestines.”
3. Hoegaarden
Unlike most beers, Belgian brands such as Hoegaarden, Westmalle Tripel and Echt Kriekenbier are fermented twice, first in the brewery and then again in the bottle. This second fermentation uses a different strain than traditional brewer’s yeast, which increases the strength of the beer, but also means it contains more potentially beneficial microbes.
“We know that even dead yeasts can have an effect on the composition of the microbiota, and also on transit times,” says Raes. “You see that when you pour the beer at the end, the final pour is a little more opaque and that is actually your yeast. My grandmother also said, “I drink that because it’s good for my circulation,” and there is probably some effect on motility, although it’s not very obvious.
4. London Porter Dark Ale
It is not only Belgian beers that contain some intestinal-promoting yeast at the bottom. Amati says you can often see this with craft or artisanal beers, as well as dark ales.
“If you look inside the bottle itself and there’s a little bit of sediment at the bottom, that’s always a good sign,” she says.
5. Stella Artois Unfiltered
If you’re going to opt for a lager, the rule is that you try to find an unfiltered version. Many drinkers prefer this because it allows for a more complex taste and aroma, but the lack of processing also means that more potentially useful chemicals are left in the drinks.
“If you drink a fairly long fermented and traditionally made beer, not one that is super filtered, you will leave some of those polyphenols and yeast strains in the beer,” says Amati.
The vast majority of beers sold in UK supermarkets are heavily filtered, but some brands, such as Stella Artois, have started to launch unfiltered ranges.
6. Doom Bar Zero alcohol-free Amber Ale
Drinking non-alcoholic beer can provide all the benefits for your intestines, without the disadvantages of the actual alcohol content. This particular brand is a good example of a darker, non-alcoholic beer that likely contains beneficial plant chemicals.
“The studies suggesting that beer could have benefits for the microbiome could certainly be a nice boost for the low-alcohol beer market,” says Amati. “But again, you’re looking for darker colored and more craft beers.”
Beers to avoid
1. Heineken
Heavily filtered and carbonated lagers contain fewer beneficial nutrients for the intestines.
2. Budweiser lager
Another filtered beer, this one contains fewer polyphenols than beer.
3. San Miguel
This popular lager probably contains fewer microbes than twice-fermented Belgian beers.
4. Peroni
Like the other filtered lagers, this beer is likely low in gut-friendly plant chemicals.
5. Stella Artois normal bearings
If you’re looking for a gut-friendly version, opt for their unfiltered lager.
6. Heineken non-alcoholic lager
Like the alcoholic versions, alcohol-free lagers are less likely to have any real benefits for your gut.
It’s not just beer: cider can be tasty too
According to Amati, there is evidence that craft cider brands – for example Old Rosie Scrumpy Cider and Henry Westons Vintage Cider – may have benefits for the gut microbiome.
“Some of the fruit usually remains in the drink, which means fermentation continues for longer,” she says. “The cloudier ciders are better because these are sugars known as polysaccharides that float in the cider and are good prebiotics to feed the gut bacteria.”
Other drinks that hark back to the Middle Ages, such as mead, which has recently seen a revival in London, are also thought to be beneficial for the gut. “All these ancient things that used to be made tend to use quite a lot of fiber from the fruit in making them, and so they may have some benefits,” says Amati.
But as always, moderation is key
However, all gut experts are keen to emphasize that alcoholic drinks do not equate to health drinks and that in many cases any benefits to the gut are likely to be negated by alcohol’s impact on the body.
“I really want to convey the message that we should drink very moderately,” says Amati. “Make sure you don’t drink alcohol for at least three days in your week, and no more than one drink if you do drink.”
NHS guidelines recommend no more than 14 units of alcohol per week – equivalent to eight cans of medium strength beer (four per cent) – and warn that alcohol increases the risk of several cancers as well as heart and liver disease.
Rossi also advocates not drinking more than one or two alcoholic drinks at a time. “When we talk about any anti-inflammatory benefits to the gut from these dark beers, it becomes pro-inflammatory after about two drinks,” she explains. “That’s because the alcohol causes the intestines to leak a bit, which allows things to get from our intestines into the bloodstream that wouldn’t normally be there, causing mild inflammation.”