In a world of ever-changing health advice, one thing seems to have stuck this year: fibre is one of the most powerful nutrients in the modern diet, and as such, we should be eating a lot more of it.
Touted for their ability to boost beneficial gut bacteria, fibrous fermented foods in particular – from sauerkraut to smoothies – have been shown to relive digestive issues, support brain health and even help protect against cancer.
But now experts at the British Heart Foundation say that eating too many gut-friendly foods could put pressure on your heart, increasing the risk of cardiovascular disease.
The problem lies not so much in the foods themselves, but what has been added to them; supermarket shelves are now packed with ‘gut health’ claims that hide the product’s true nutritional value.
Tracy Parker, nutrition lead at the BHF says: ‘We encourage everyone to choose food that can keep their gut microbiome healthy.
‘The benefits are clear, and we are continuing to improve our understanding of how a gut friendly diet may help our hearts.
‘But a lot of these products can contain high levels of salt or sugar, so it’s important to be aware of the potential drawbacks,’ she added.
‘By ensuring you check package labels for added salt and sugars, and eat each in moderation, you can make sure the risks do not outweigh the benefits for your heart health.’
So which gut-friendly foods should we be particularly wary of when it comes to looking after our hearts?
Salty Sauerkraut
Fermented and fibrous, sauerkraut is one of the best foods you can eat to boost gut diversity, feeding the thousands of beneficial bacteria that reside in our guts.
Much like kimchi, traditional sauerkraut relies on a lot of salt for fermentation, which could be a concern for anyone watching their blood pressure, Parker says.
Sauerkraut is made by submerging cabbage in saltwater for an extended period of time. This creates an oxygen-free environment that allows beneficial bacteria to flourish.
But it can also mean that the final product ends up being relatively high in salt, which has been shown to raise blood pressure and increase the risk of a heart attack or stroke.
‘To avoid overdoing it, it’s worth checking the label and eating small portions only,’ the nutritionist advices.
There are also some low-salt versions available.
That said, there is evidence to suggest that fermented foods can actually help lower cholesterol, therefore reducing the risk of suffering a major heart event.
Cholesterol is a type of fat found in all cells in the body. But when levels of good cholesterol fall too low, so-called bad cholesterol can build up unchecked.
Over time, this restricts blood flow, increasing the risk of heart attack, stroke and even dementia.
But studies have shown that eating a small bowl of kimchi every day can significantly lower levels of bad cholesterol – by turning it into coprostanol, a waxy substance that cannot be absorbed by the body.
Some shop-bought varieties are also pasteurised, Parker warns, which removes most of the live bacteria.
‘If you want the beneficial probiotics, make sure you’re getting unpasturised sauerkraut – which is generally fine for most healthy adults – which will be indicated by phrases like “raw” or “contains live cultures” on the packaging.’
Fruity yoghurts
Live, plain and sugar free yoghurt typically gets the green light when it comes to our health.
It’s full of calcium to support bone health, which is crucial for aging bodies. It’s famously good for our gut health, as its packed full of gut friendly bacteria that feeds our microbes.
And a recent study suggested that eating just two servings a week can help protect against bowel cancer.
Research even suggests that the calcium, magnesium and potassium in yoghurt may support heart health as these minerals help to regulate blood pressure.
The caveat, experts agree, is that the type of yoghurt we eat really matters – with flavourings, emulsifiers and sugar often injected to enhance taste and texts, even in those that boast gut health claims.
‘Many flavoured or fruit-based yoghurts contain added sugars and may have fewer live cultures than the plain versions,’ Parker explains.
‘That why the BHF recommends choosing plain yogurt with live and active cultures mentioned on the label to ensure you are buying a low sugar option that is good for your gut.
‘You can add whole fruit at home for a healthier way to add sweetness.’
Sugar-laden Kombucha
Whilst the thought of sipping on fermented tangy tea may not seem all the appealing, more of us are drinking kombucha than ever for it alleged gut health benefits.
Traditionally it’s made from just four ingredients: black or green tea, water, sugar and a scoby – which stands for symbiotic culture of bacteria and yeast.
The disc-shaped culture converts the sugar into alcohol which the bacteria then breaks down into acids giving the drink its characteristic tangy flavour.
It’s a probiotic meaning it contains living bacteria which produce short-chain fatty acids in the gut which have been linked to reduced inflammation, and better heart and circulatory health.
But, as the BFH warns, many kombucha products contain added sugar, preservatives, artificial sweeteners and flavourings.
‘This can lead to weight gain, which in turn can increase the risk of a heart attack or stroke,’ Parker says. ‘That’s why the BHF encourages people to choose lower sugar varieties, often labelled as no added sugar.’
Smoothies aren’t fibre-packed
An apple a day will keep the doctor away, but only if you eat it whole
While a smoothie packed full of fibrous fruits may seem like a healthy way to start the day, blitzing up fruits changes their structure, releasing free sugars that spike blood sugar levels in the body, Parker says.
‘And only one 150ml serving of any smoothie counts towards your five-a-day, so the BHF recommends sticking to that portion size,’ she added.
While they still offer some fibre and compounds good for gut health, such as plant compounds called polyphenols, there are more gut and heart friendly ways to start the day.
‘Try adding nuts and seeds for extra protein and fibre, which help keep blood sugar levels more stable, meaning you can still enjoy your smoothie whilst minimising the risk of spiking blood sugar levels, which can increase the risk of type 2 diabetes, heart and kidney disease,’ the nutritionist advised.
