By: Glenn Cardwell - Accredited Practising Dietitian
Reader Gillian Street alerted me to a news item suggesting that we had found a way to reduce the energy (Calories/kilojoules) in rice by 10%, and possibly by as much as 50% soon, and this would result in a healthier rice.
Immediately I was sensing a headline and not a story.
Creating resistant starch
Researcher Sudhair James reported at a conference that if you added coconut oil to simmering rice, then chilled the rice for 12 hours after cooking, the proportion of resistant starch increases.
To make sense of this first we need to know what is resistant starch (RS). We don't digest all of the starch in food. Some of it is in a form that is resistant to digestion, hence the term. The undigested starch then goes into the large bowel to be consumed by the resident friendly bacteria. This is good, being the main role of dietary fibre too. Foods such as breads, pasta, legumes, bananas, potatoes and corn chips all provide a reasonable amount of RS.
We already knew that if you cool cooked rice, pasta and potatoes that the level of resistant starch rises, meaning that you digest less starch in a cold rice, pasta or potato salad than in hot stir-fried rice, spaghetti marinara or baked potatoes. The cooled starch becomes less soluble and harder to digest.
What are the potential benefits of RS? It helps lower the Glycemic Index of a meal, has a laxation effect, increases the satiety of the meal, and as the healthy bacteria in your large bowel chew through the RS they produce acids that protect the bowel lining, reducing the risk of bowel cancer. Pretty cool eh?
10% fewer Calories
OK, back to the rice story. Sudhair James' cooking method reduced the kJs by about 10%, which is quite minor in the scheme of things. Why not just eat a little less rice or, even better, not eat that biscuit or pastry for morning tea, or not buy the Maltesers at the movies, or the cake with coffee. It's quicker, easier and more effective than going through the cook-add-oil-chill-for-12-hours-then-microwave process of saving a few Calories. A cup of steamed rice is 960 kJs (230 Cals) so a 10% saving is 96 kJs (23 Cals) or about one-third of a chocolate biscuit. Get my drift?
Maybe a company will produce rice that has been pre-cooked with oil and dried before putting a packet, but a reduction of 10% kJs would have a net result of zero when it comes to body weight, in my opinion.
OK, but what if they get up to a 50% cut in kJs, wouldn't that shatter the earth in some manner? Yes, I suppose so, but that is purely speculative for the sake of the story, in my view.
What does it all mean?
Right now we eat an average of 5g of resistant starch each day, yet our goal should be closer to 20g. A rice with more RS could have potential health benefits, no doubt. My guess is that it will come at a premium cost, and may even cause some gut discomfort with all that RS being eaten by bacteria creating gas as a by-product. In the meantime, I suggest you do something radical, yet exceptionally dull, which is to eat regular rice and serve with wholesome plant-based foods and maybe a little meat. No way that will get you a headline.
Glenn is an Accredited Practising Dietitian with 32 years in clinical and public health nutrition.
For more information visit www.glenncardwell.com