Denis Burkitt and Hugh Trowell first made the link between fibre and colon health in the 1960s. They came up with the fibre hypothesis after observing that in Africa where lots of fibre was consumed they had low rates of bowel problems including diverticulitis or colon cancer. Their recommendations for consuming more fibre are still in place today and most countries around the world have “eat more fibre” as one of their dietary guidelines. Here in Australia, food surveys over recent years have shown that we are indeed taking heed and we have been eating more fibre. But colon cancer rates are not dropping and we still seem to have many problems with bowel health. In fact Australia has one of the highest rates of colon cancer in the world. This is what has been dubbed as the Australian Paradox. So what on earth is going wrong?
Well it seems that the original advice to simply eat more fibre, is overly simple. Just as we have learned that different types of fat are important, different types of carbohydrate-rich foods have varying effects and different proteins are important, we now know that different types of fibre are required. To only look at total fibre intake ignores these nuances. You have probably heard of insoluble and soluble fibre. You can think of insoluble as being what my Mum used to call ‘roughage’. That’s the bran-y stuff .. the husk on the outside of brown rice and barley. It’s what gives wholegrain cereals their toughness and certain vegetables their strength – think of the stem of an asparagus. Insoluble fibre is terrific at keeping you regular as it bulks out the intestinal contents and keeps everything moving along. Think of it as an intestinal broom sweeping out your gut. This is the type of fibre we have been eating more of as we consume more wholegrain products.
Soluble fibre dissolves in water – hence the name. You’ll find this type of fibre within the flesh of fruits like an apple and in legumes (beans, chickpeas and lentils). It absorbs water in the gut and swells to a gel-like consistency. This slows the attack of enzymes on the carbohydrates present and in turn slows their absorption, lowering the GI of the food. A good thing. The bulking effect of this gel in the gut also has the added effect of stimulating the gut to contract so again plays a role in keeping you regular.
The third type of fibre is relatively new to research and has only recently been accepted as a fibre. This is resistant starch. This is starch that is resistant to our digestive enzymes and so it enters the colon where it acts as gold premium fuel to the resident bacteria. Fortunately it’s the good ones that seem to really like it. Resistant starch just might prove to be the missing link and explain the Australian Paradox. By feeding and promoting the growth of these good bacteria, they oust the bad guys and the fermentation that goes on as a result produces by products (short chain fatty acids) that keep the cells lining the colon healthy. Research recently released from CSIRO backs up this hypothesis. They showed that resistant starch helps the colonic cells to resist damage from carcinogens – the first step in the development of cancer. This research was published in The Journal of Nutrition.
Based on their research CSIRO are recommending a target of 20g a day of resistant starch. So forget sprinkling barn on your breakfast, its resistant starch you need more of. Interestingly I am just back from Japan and while they don’t eat much bran-y type foods, they do eat plenty of reheated and cold rice – a great source of resistant starch. Legumes, cold pasta and potato, firm bananas are other terrific sources. CSIRO have recognised however that even with eating more of these foods it can be hard to meet the 20g target (anyone keen on 3 cups of lentils?). This is why they have a program in place to develop grains with higher levels of resistant starch. Barleymax is the first of these grains. It’s a superior grain not only because of its high fibre level, but the extraordinary amount of resistant starch it contains compared to regular grains. Your gut bacteria may have a field day when you first start eating the product, so don’t be worried if you feel a bit windy for the first few days! It will calm down as your gut bacteria adapt and your colon is working as it should. So for a healthy bottom line get eating more resistant starch as part of your daily fibre mix.