Adding more fibre to your daily diet can help keep your immune system fighting fit
Make a quick tally of the foods you’ve eaten over the last few days. Top marks if your diet contains plenty of foods with roughage in them, such as wholegrains, fruits and vegetables. If you can only list the occasional glass of fruit juice and a solitary helping of veg with your main meal, your menu could do with a revamp.
New research from the Garvan Institute of Medical Research in Australia has revealed some new reasons why we should follow the old advice to eat more roughage – especially the kind nutritionists call insoluble fibre.
The research, published in the journal Nature, explains new findings that connect our diet with the health of our immune systems. Insoluble dietary fibre is well-known for the part it plays in keeping our digestive system working well, and saving us from the discomfort of constipation. Now Australian scientists have discovered that it is also important for our immune system, and can help protect us from a number of diseases.
Roughage works its way through the digestive tract unchanged until it gets to the colon. There, bacteria convert it into energy and into ‘short chain fatty acids’, which help to lessen the symptoms of colitis, an inflammatory gut condition. Probiotics and prebiotics, food supplements that have an effect on gut bacteria, may also help lessen the symptoms of inflammatory diseases, asthma and rheumatoid arthritis. Thanks to the new research, scientists now have a greater understanding of how diet, gut bacteria and our immune system are linked.
“The notion that diet might have profound effects on immune responses or inflammatory diseases has never been taken that seriously”, said Professor Mackay of the Garvan Institute. “We believe that changes in diet, associated with western lifestyles, contribute to the increasing incidences of asthma, type 1 diabetes and other autoimmune diseases. Now we have a new molecular mechanism that might explain how diet is affecting our immune systems.”
“We’re also now beginning to understand that from the moment you’re born, it’s incredibly important to be colonised by the right kinds of gut bacteria,” added PhD student Kendle Maslowski. “The kinds of foods you eat directly determine the levels of certain bacteria in your gut.”
So where do we go for extra fibre?
Wholegrains – bread, rice and breakfast cereals, are good sources of insoluble fibre, the sort our bodies can’t digest. It helps keep our bowels healthy by keeping other foods moving along.
Fruits high in insoluble fibre include those we eat with the peel on, such as apples, peaches, nectarines and plums, and those that contain edible seeds, for instance, berries.
Vegetables with plenty of insoluble fibre include broccoli, green beans, asparagus, cabbage, cauliflower and spinach.
Most of us need to eat more fibre. The average intake is 12g of fibre a day; the recommended adult intake is 18g per day.