The health benefits of beans: How they help to prevent dementia and boost longevity

However, we aren’t just referring to baked beans or one type of bean in particular. “Variety is the spice of life,” says Dr Linia Patel, a registered dietitian and spokesperson for the British Dietetic Association.

“Aim to include a variety of beans (chickpeas, butter beans, cannellini beans, kidney beans, baked beans) in your diet for optimal health.”

She adds that while there are no specific guidelines for the intake of beans in your diet in the UK, a portion – which is equivalent to three heaped tablespoons or 80g of beans – counts as one of your five a day.

Beans are a plant-based source of protein, fibre, iron and vitamins that support our health in many ways, and might even help us to live longer. 

The health benefits of beans include:

• Decreased risk of heart disease
• Improved gut health
• Healthier brain ageing
• A reduced risk of various cancers
• Management and prevention of type 2 diabetes

Indeed, beans, beans really are good for your heart. Patel says: “Recent evidence shows there is a clear link between eating beans and a lower risk of coronary heart disease, which is a leading cause of death in the UK.”  

The high fibre content of beans plays a role in this. For example, a portion of cannellini beans provides around 9g (a third of an ounce) of fibre, which is almost one third of an adult’s daily recommended intake of 30g (one and a half ounces). “[A higher intake of] fibre helps to reduce the risk of chronic diseases such as cardiovascular disease,” says Patel. However, Wilson explains: “According to government health surveys, there isn’t a single age group in the UK that is meeting the fibre-intake recommendations.” This could mean that our hearts “are missing out on important protection”. 

More diverse gut bacteria mean the gut is considered healthier, which supports our overall health. But as we age, our gut microbe diversity decreases. Don’t worry though, because beans are on hand. “Eating a variety of beans has been shown to increase the number of beneficial bacteria and improve intestinal function,” says Patel.  

That said, it’s also true that the more beans you eat, the more gas and stomach discomfort you may experience. Patel says these are common unpleasant or painful symptoms of eating beans. “Dried beans are thought to cause more bloating,” she adds. So how can we gain the gut benefits without the gut discomfort? Patel suggests: “Soaking the dried beans in hot water and draining them before cooking can help to reduce the digestive symptoms.” 

So, beans support the gut, and the gut-brain axis – a two-way communication system between the gut and the brain – helps them to aid our brain health.

This is because certain types of gut bacteria break down the fibre in beans, which “produce compounds that help to support the integrity of the blood-brain-barrier (BBB) – the primary structural barrier between the brain and the blood that prevents unwanted toxins and pathogens from crossing into the brain”, says Wilson. 

“It is well known that compromised BBB integrity can result in neuroinflammatory, neurodegenerative illnesses and disorders, such as dementia,” she continues. Again, owing to most of us not getting enough fibre, this could be risking the health of our guts and brains. 

In a recent study by Patel and other researchers, “findings showed that including two portions or 200g [seven and a half ounces] of legumes [80g (3oz) dried legumes] could reduce your risk of several types of cancer, including colon, ovary and kidney,” she says. Just as it can help to protect our hearts, the high fibre content of beans could also be protecting us from these chronic diseases; high-fibre diets have been found to reduce the risk of certain cancers, including bowel cancer, breast cancer and colorectal cancer.  

Some research has also shown that beans act as antioxidants and have anti-cancer properties, although more research is needed.  

If you have prediabetes or type 2 diabetes, beans may be able to help. Once again, it’s the fibre in beans that is responsible for this. “It keeps you fuller for longer, which can be good for helping you to maintain your weight,” says Patel.

“Eating more fibre also helps to keep your blood sugar levels in check, which is a challenge as you get older.” Managing both of these factors is key to helping to avoid or control type 2 diabetes and prevent complications. 

Patel shares some easy ways to reap the health benefits of beans:

• Try swapping half the meat in your favourite dish for a tin of beans; for example, spaghetti bolognese or shepherd’s pie. 
• Add beans to soups, salads, stews and curries.
• Add beans to your baking – yes, really! You could give the BBC’s black bean brownie recipe a go.