Guinness is Good for You is one of the most famous advertising campaigns in history, but away from the slogans and billboards, it appears there could have been a grain of truth in the suggestion that everyone’s favourite stout does something positive for the body......See Full Story>>.....See Full Story>>
In recent years, researchers have been accumulating evidence to suggest that certain beers could help improve the diversity of species in the gut microbiome, something which tends to be associated with health benefits. Last year, a study in the Journal of Agricultural and Food Chemistry followed 22 men who drank a little more than half a pint of beer every day for four weeks and found that they subsequently had better markers of intestinal health.
Now, a review of experiments published in the journal Frontiers in Nutrition has concluded that the various ingredients within beer may have a positive impact on the immune system, when broken down and fermented within the gut.
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, which are known to be useful foods for the bacteria in the gut. “Bacteria have been shown to digest about 90 per cent of polyphenols and turn them into chemicals, which can have anti-inflammatory effects,” she says.
However Belgian professor Jeroen Raes, who has examined the possible effects of beer on the microbiome as part of the Flemish Gut Flora Project, cautions that we still know relatively little and that the alcohol within beer may cancel out any positive findings.
“My feeling is that if beer has an effect on the gut, the effect size will be relatively limited,” he says. “And I’m not certain that it’s by definition, a beneficial one.”
But scientists believe that the emerging research points to some beers being potentially better for you than others. Here are some gut-friendly recommendations, and some to maybe leave behind the bar.
From the 1920s to the 1960s, marketing taglines such as My Goodness, My Guinness and Guinness for Strength firmly established the brand as arguably the world’s most popular stout.
But while there are no suggestions Guinness adds muscle mass, it is thought 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’s the case for drinks as well. So, if you drank a little bit of Guinness one night, and then a little red wine another time, while keeping within the alcohol limit, that’s probably going to get you a wider range of these polyphenols.”
“It’s not a health drink, but some of these ales will contain more of these useful chemicals as well as yeast strains left in the beer,” says Federica Amati, a medical scientist at Imperial College London. “They’re probably not going to be alive, but there’s a vein of thought that they still have some sort of beneficial impact on our immune system when they reach the gut.”
Unlike most beers, Belgian brands such as Hoegaarden, Westmalle Tripel and Echt Kriekenbier are fermented twice, initially in the brewery and again in the bottle. This second fermentation uses a different strain from the traditional brewer’s yeast, which increases the strength of the beer, but also means that it contains more potentially useful microbes.
“We know that even dead yeasts could have an effect on the composition of the microbiota, and it could also have an effect on transit times,” says Raes. “You see that if you pour the beer at the end, the final pour is a bit more opaque and that’s actually your yeast. My grandmother would also say, ‘I’ll drink that because it’s good for my transit,’ and there’s probably some effect on motility, although it’s not super clear.”
It’s not just Belgian beers that contain some gut-boosting yeast at the bottom. Amati says that you can often spot this with craft or artisan beers, as well as the darker ales.
“If you look in the actual bottle and there’s a little bit of sediment on the bottom, that’s always a good sign,” she says.
If you are going to opt for a lager, the rule is to try and find an unfiltered version. Many drinkers prefer this as it allows for a more complex flavour and aroma, but the lack of processing also means that there are more potentially useful chemicals left in the drinks.
“If you drink a fairly long fermented and traditionally made beer, so not one that’s super filtered, you will get some of those polyphenols and yeast strains left 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 begun to launch unfiltered ranges.
Drinking alcohol-free beers could offer all the benefits to your gut, without the disadvantages of the actual alcohol content. This particular brand is a good example of a darker, non-alcoholic ale which is more likely to contain helpful plant chemicals.
“If anything, the studies suggesting that beer could have benefits for the microbiome could be quite a nice boost for the low alcohol beer market,” says Amati. “Once again though, you’re looking for those darker coloured and more artisan ales.”
Heavily filtered and carbonated lagers are going to contain less beneficial nutrients for the gut.
Another filtered beer, this will have less polyphenols than ale.
This popular lager is likely to contain fewer microbes than the twice-fermented Belgian beers.
Like the other filtered lagers this beer is likely light on gut-friendly plant chemicals.
If you’re looking for a gut-friendly version opt for their unfiltered lager.
Just like the alcoholic versions, alcohol-free lagers are less likely to have any real benefits for your gut.
According to Amati, there is some evidence that artisan cider brands – for example Old Rosie Scrumpy Cider and Henry Westons Vintage Cider – can have benefits for the gut microbiome.
“They tend to have some of the actual fruit left in the drink, meaning that fermentation carries on for longer,” she says. “The cloudier ciders are better as these are sugars known as polysaccharides which float in the cider and they’re good prebiotics to feed the gut bugs.”
Other drinks, which hark back to medieval times, such as mead which has seen a recent resurgence in London, are also thought to be beneficial for the gut. “All this ancient stuff made back in the day tends to use quite a lot of the fibre from the fruit in making it, which is why they could have some benefits,” says Amati.
However, all gut experts are keen to emphasise that alcoholic drinks do not equate to health drinks and in many cases, any benefits for the gut are likely to be cancelled out by the impact of alcohol on the body.
“I’m very keen to pass on the message that we have to drink very moderately,” says Amati. “Have at least three days with no alcohol in your week, and no more than one drink when you do drink.”
NHS guidelines recommend no more than 14 units of alcohol per week – equivalent to eight cans of average strength (four per cent) beer – warning that alcohol raises the risk of multiple cancers as well as heart and liver disease.
Rossi also advocates drinking no more than one or two alcoholic drinks at a time. “When we’re talking about any anti-inflammatory benefits for the gut from these darker beers, that becomes pro-inflammatory after about two drinks,” she explains. “That’s because the alcohol starts to make the gut a little bit leaky, allowing things to move from our gut into the bloodstream that wouldn’t normally be there, and causing low-grade inflammation.”