Carbohydrates are not typically considered a part of a healthy diet, but they undergo a transformation when subjected to cold temperatures. When pasta, potatoes, and rice are cooled, their composition changes, converting them into resistant starches. This alteration makes them more challenging to digest and beneficial for your gut health.
Interestingly, refrigerating certain leftovers overnight can promote gut health. According to Leena Hilakivi-Clarke, a professor of food science and nutrition at the University of Minnesota, foods like pasta, rice, quinoa, and potatoes contain a unique type of dietary fiber known as microbiota-accessible carbohydrates (MACs). While all forms of fiber are advantageous, MACs are particularly effective in enhancing gut health because of their positive impact on the gut microbiome, acting as natural prebiotics.
Initially, most starchy foods do not possess high levels of MACs when freshly prepared. However, the simple act of refrigerating pasta, potatoes, quinoa, and rice can transform them into gut-healthy options. Here’s how this process unfolds:
Turning ordinary foods into resistant starches: Rice, potatoes, and pasta may not appear to offer many health benefits when consumed freshly cooked. This perception arises because their gut-supporting properties remain latent at this stage. Refrigerating these carbohydrates induces a transition into “resistant starches,” a special type of dietary fiber that offers significant health advantages.
When cooled, the starches in these foods undergo a structural change known as “starch retrogradation.” Following this transformation, these newly resistant starches become more resistant to digestion, even when reheated. This ensures they reach your large intestine, where they can nourish the resident bacteria, contributing to improved gut health.
One of the notable advantages of resistant starches is their classification as MACs—natural prebiotics that, as per Hilakivi-Clarke, can substantially enhance gut health. MACs, a form of fiber, enable “gut bacteria to produce various metabolites that benefit the body,” supporting the immune system and cellular metabolic pathways.
These chilled, starchy foods may be particularly beneficial for individuals with diabetes. Hilakivi-Clarke’s husband, upon being diagnosed with prediabetes, believed he had to eliminate rice and pasta from his diet. However, since cooked and cooled rice and pasta convert into MACs, they are, in fact, beneficial for one’s health.
Research corroborates this claim, with a 2019 study demonstrating that resistant starches can improve insulin resistance and glucose levels in diabetic patients. Additionally, a 2020 review suggested that consuming more resistant starch could help prevent the onset of type 2 diabetes and obesity.
Now, Hilakivi-Clarke and her husband can enjoy these foods together, with the added benefit of improved gut health, just by waiting a day after cooking.
Disclaimer: The views, suggestions, and opinions expressed here are the sole responsibility of the experts. No Digest Pulse journalist was involved in the writing and production of this article.
