Chilling cooked starches like potatoes, rice, and pasta doesn’t just make them palatable cold – it changes their chemical structure in a way that could benefit your health. This phenomenon, driven by the formation of resistant starch, is gaining attention for its potential to improve blood sugar control, gut health, and even weight management. But how much of this is hype, and how much is backed by science?
What is Resistant Starch?
Unlike typical carbohydrates that are rapidly broken down into glucose, resistant starch avoids digestion in the small intestine. This means it behaves more like fiber than sugar, offering different metabolic effects. The key is the cooling process: when starches are heated and then cooled, their molecular structure shifts, creating a new form that resists enzymatic breakdown.
The Potential Benefits: Blood Sugar, Gut Health, and Weight
The excitement around resistant starch stems from several areas:
- Blood Sugar Control: Studies suggest that consuming chilled starches may lead to smaller blood sugar spikes compared to freshly cooked versions. A 2023 study, for example, showed that freezing bread slowed blood sugar increases, potentially reducing diabetes risk.
- Gut Health: Resistant starch isn’t absorbed in the upper digestive tract, so it reaches the large intestine where gut bacteria ferment it. This fermentation produces short-chain fatty acids (SCFAs), particularly butyrate, which lowers gut inflammation and supports intestinal health.
- Weight Management: The idea here is that resistant starch reduces calorie absorption. However, research on weight loss is mixed. A 2014 review found no direct link between resistant starch intake and body weight changes.
The Microbiome Factor: Why It Doesn’t Work for Everyone
The gut benefits of resistant starch aren’t universal. Only specific bacteria – Ruminococcus bromii and Bifidobacterium adolescentis – can convert resistant starch into beneficial SCFAs. Since everyone’s gut microbiome is unique, some people will experience more pronounced effects than others.
“Not every person will have the same gut-level response to resistant starch,” says Kim Kulp, a gut health expert. This means that while chilling leftovers might be helpful, it won’t be a magic bullet for everyone.
Is It Worth Trying?
The science suggests that refrigerating or freezing starches is low-risk and potentially beneficial. Dr. Laura Purdy points out that if it works for you, there’s no harm in incorporating this practice into your routine.
Ultimately, while resistant starch isn’t a guaranteed health breakthrough, it’s a simple dietary tweak that could yield modest benefits, especially for those with gut bacteria capable of fermenting it effectively.
