Why eating pasta and rice as leftovers could be better for you than having them freshly cooked
Eating carbohydrates like rice, potatoes and cold pasta reduces the risk of some of America’s biggest killers, such as cancer, diabetes and heart disease, according to experts.
Researchers have discovered that starch molecules in carbohydrates change structure when they are cooked and then cooled, leading to a range of intriguing benefits.
Crucially, the compounds – known as resistant starch – become harder to digest, meaning some sugars in carbohydrates are not absorbed into the bloodstream, Dr. Balazs Bajka, an intestinal physiologist at King’s College London in Britain, at the New York Times.
This means that blood sugar levels are kept more stable, making us feel full longer and less likely to snack.
Resistant starch also contains fewer calories, about half the calories per gram as freshly cooked carbohydrates.
Resistant starch resulting from refrigerating foods such as brown rice and pasta contains fewer calories, about 2.5 calories per gram, while regular starch contains 4 calories per gram.
Studies have shown that leftover carbohydrates can also trigger the release of more satiety hormones cholecystokinin (CCK) and glucagon-like peptide 1, or GLP-1 (the active ingredient in the anti-obesity blockbusters Wegovy and Zepbound) .
Experts also say that resistant starch can nourish healthy bacteria in the gut, which is said to help protect against a range of diseases, including heart disease.
Recently, evidence has emerged to suggest that eating resistant starch may reduce the risk of developing certain types of hereditary cancers.
A study published in 2022 in the journal Cancer prevention research suggested that resistant starch helped reduce the incidence of esophageal, stomach, bile duct, pancreatic and duodenal cancers in people with genetic susceptibility.
The patients were divided into two groups: 463 people took a resistant starch supplement every day for four years, while 445 took a placebo drug.
Resistant starch decreases slightly when you cool and then reheat carbohydrates, experts say
After 10 years, there were five new cases of upper gastrointestinal cancer in the starch group, and 21 in the placebo group.
Dr. John C. Mathers, study author and professor of human nutrition at Newcastle University in Britain, said: ‘We discovered that resistant starch reduces a range of cancers by more than 60%. The effect was most pronounced in the upper part of the intestine.
‘This is important because cancer of the upper gastrointestinal tract is difficult to diagnose and often goes undetected at an early stage.’
Meanwhile, testimonials from doctors championing resistant starch have skyrocketed on TikTok, with more than 1.3 million videos sharing the health tip.
On TikTok, fitness guru Jason Wittrock shows how refrigerated rice led to a less dramatic blood sugar spike, compared to freshly cooked rice
Diabetes patients have also taken to the platform to show the difference in blood sugar spikes after eating chilled rice.
Some experts say that heating up the cold carbs can reduce the amount of resistant starch you consume.
A 2020 study published in the journal Nutrition Bulletin found that cooking, cooling, and then reheating rice reduces resistant starch by 20 percent. Kim Rosea registered dietitian and diabetes expert, said this drop was “not much.”
‘The resistant starch in a cooked, then cooled and then reheated potato will decrease much further because different carbohydrates have different proportions of the type of starch they contain.’
Additionally, studies have also shown that resistant starch can nourish cells in the intestines by increasing the production of a substance called butyrate.
Butyrate has been shown to do this reduce the level of inflammation in the intestines and detect DNA damage, potentially preventing the growth and replication of cancer cells.
Last year, researchers at RMIT University in Australia developed a tasteless type of resistant starch that could be added to foods to improve their nutritional value.
The technology, called FiberX, is said to have ‘potential to help with weight management and diabetes’, according to the makers.