Healthy diet: Eat more fiber to fight COVID, heart disease and even cancer

Dietary fiber and a healthy gut is the key to better immune systems, skin, sleep and energy – here's what foods to eat

Healthy breakfast
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Fiber is extremely important for a healthy diet. If you're just doing some research on health and fitness to kick-start your new year's resolution, you've probably already found article after article telling you how important gut health is. It's not just for good digestion: your diet can impact all sorts of things such as your sleep, energy levels, skin, mental health and – especially important these days – your immune system.

You might be using some of the best fish oil supplements or best vitamins for women over 50 to try and supplement your diet with lots of healthy micronutrients, and that's a good start. However, in order to supercharge your gut health, you need to first be eating lots of dietary fiber, which aids digestion by adding volume to your stool, helping it pass easily through the body. 

Good gut health is essential for a healthy immune system, which is why new research has found dietary fiber is essential for people undergoing immunotherapy, aiding their fight against dangerous diseases such as cancer. The researchers from the University of Texas and the National Institutes of Health (opens in new tab) looked at people undergoing immunotherapy to fight melanoma, and found high dietary fiber intake in humans was associated with "disease non-progression". That's not to say a good diet alone can ward off skin cancer – far from it – but better gut health can improve your immune system. 

Woman holding an apple

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Oregon State University's Andrey Morgun wrote: "The influence of the gut microbiome on therapeutic response has been demonstrated in numerous studies, in preclinical models and also in research involving human cohorts." The researchers found melanoma patients receiving 'immune checkpoint blockade' therapy, that makes it easier for their immune system to kill cancer cells, respond to treatment better when their diet is rich in fiber.

It's supported by other research, from the British Journal of Nutrition (opens in new tab), stating there is "increasing evidence" that fiber can modulate various aspects of the immune system and a good diet can help with the immune response. 

The immune system is vital for all of us, not just those undergoing immunotherapy – and in the post-pandemic age, there's evidence (opens in new tab) of a healthy immune system playing a role in reducing the symptoms and impact of COVID-19. A healthy body will never replace a vaccination, but people with co-morbidities such as a compromised immune system or high BMI are considered to be more at risk from the virus.

Hate getting sick? Opt for fibrous orchard fruits, such as apples, pears and oranges, along with cruciferous veggies such as broccoli. Cereal fibers from whole grains such as oats (sugary cereals don't count, unfortunately) are also extremely beneficial, and should factor in to any new-years diet plan you may be taking on.

Finally, remember to reduce the amount of processed foods you consume and hydrate well to keep your digestive health tip-top – our best water bottles page can help you maintain good water consumption habits in the gym and on the go.

Matt Evans
News Editor

Matt Evans is an experienced health and fitness journalist and News Editor at Fit&Well, covering all things exercise and nutrition on the Fit&Well website. Matt originally discovered exercise through martial arts: he holds a black belt in Karate and remains a keen runner, gym-goer, and infrequent yogi. His top fitness tip? Stretch.