COOLING CARBS LIKE RICE AND PASTA BEFORE CONSUMING THEM TURNS THEM INTO RESISTANT STARCH, WHICH IS GOOD FOR YOUR HEALTH.
Leftovers hold a special place in the Indian plate and palate, with nifty grannies whipping up delectable dishes out of last night’s rice and roti in mere minutes. Whether it’s the fermented ‘paanta bhaat’ (served as ‘smoked rice water’ in Masterchef Australia no less) or ‘roti churma,’ curd rice and ‘phodnichi poli’ (tossed and tempered leftover chapati bits), every kitchen across the country has a leftover recipe or two.
Experts have now found that these leftovers are good for your gut, blood sugar levels and ever-widening waistline. In fact, leftover carbs like rice, chapatis, pasta, boiled potatoes and even overnight oats magically morph into healthier versions once left to cool for a few hours or refrigerated. That’s because all the starch in them turns into resistant starch (RS).
What is that? It’s a pro-max version of regular carbs with half the calories. “Starch that cannot be digested by the small intestine and must go to the large intestine to be broken is called resistant starch. It has around two calories per gram, while regular carbohydrates would have four to five calories. So, our grandmothers clearly knew what they were doing.”
Resistant starch is primarily fiber, a complex carbohydrate that causes 40-50% less spike in blood sugar levels. “It’s considered a prebiotic as it breaks down in the large intestine, feeding the gut microbiome. Research has found that when you cook high-starch foods like rice, roti, pasta, and potatoes, cool them and then consume them, you convert 50% of their simple carbohydrate into RS, something that lettuce or carrots would naturally have. This reduces the glycemic index of such foods as well.”
But how can simply putting cooked, calorie-dense regular carbs in the fridge and consuming them the next day turn them into high–RS food? Cooking and cooling causes the food’s starch molecules to get tightly packed, making them more difficult to digest. “When this happens, some of the starch becomes ‘resistant’, meaning its sugar molecules aren’t as broken apart and absorbed into your bloodstream as they normally would be.” Even when you reheat the food as leftovers the following day, most of the RS formed during cooling will remain.
As resistant starch has less calories and takes more time to digest, it improves feelings of satiety after eating. RS reshapes gut microbiota, leading to weight loss. “The body weight, waist circumference and fat mass of participants significantly decreased from week 2 onwards. Both visceral fat areas and subcutaneous fat areas were lower following RS consumption.”
RS is an important substrate for the synthesis of short-chain fatty acids (SCFA) that are crucial to maintain gut health and metabolism. But it greatly benefits the colon as well. “The most important of these SCFAs is butyrate, the preferred fuel of the cells that line the colon. RS lowers the colon’s pH level, potently reduces inflammation and lowers risks of colorectal cancer; the fourth most common cause of cancer deaths worldwide.” SCFAs that aren’t used by the colon cells travel to the bloodstream, liver and the rest of the body, regulating the immune system, improving insulin resistance, protecting the heart and other organs, as well as the nerves.
RS may also help with various digestive disorders and inflammatory bowel diseases like ulcerative colitis and Crohn’s disease, constipation, diverticulitis, and diarrhea. Daily RS intake in adults with type 2 diabetes for 8-12 weeks showed favorable cardio-metabolic outcomes and reduced inflammation.
Broadly, there are four kinds of resistant starch. Natural resources or raw foods make up two kinds — RS1 is found in whole grains, legumes, nuts and oilseeds and RS2is found in some fruits (jackfruit, bananas, guava), cereal (oats, puffed wheat, museli, cornflakes, uncooked rice) and vegetables (raw banana, raw potato, carrot, sweet potato, peas, beans).
“RS3 is, of course, the cooked and cooled sources known as retrograded starch mainly used as a fiber supplement or added to bread, pasta and cakes to enhance fiber content.”
Using leftover carbs ensures health as well as wealth by way of reducing food wastage. However, excess RS in one’s diet can be too much of a good thing. “As RS is fermented by the gut bacteria, it leads to bloating and people can either get constipated or diarrhea, apart from nausea. Not everyone can tolerate all types of RS. Also, people with an actively inflamed gut do not have enough good bacteria to work on the RS foods. So, their symptoms might flare up if they consume too much. My advice would be to take it slow and keep adding RS foods one at a time to the diet to avoid side effects.”
FOUR TYPES OF RESISTANT STARCH:
TYPE 1: Found in grains, seeds, and legumes. Resists digestion because it binds with fibrous cell walls in one’s food.
TYPE 2: Found in starchy foods like raw potatoes and unripe green bananas.
TYPE 3: Forms when starchy foods like rice and potatoes are cooked and then cooled.
TYPE 4: Which is a man-made resistant starch created through a chemical process.
