Harvard Nutritionist Reveals Simple Method to Reduce Carb Glycemic Index by 50%

Controlling blood sugar levels is important for overall health maintenance, especially for individuals with diabetes or for those aiming for weight control. Recent insight from Dr. Terry Shintani, MD, JD, MPH, KCSJ, a Harvard Trained nutritionist, offers a straightforward method to significantly reduce the glycemic index (GI) of common carbohydrate rich foods, potentially transforming dietary approaches to blood sugar management.

Glycemic index is a value that ranks foods according to their effects on blood sugar levels. High-GI foods (values greater than 70) induce quick surges in blood sugar levels, whereas low-GI foods (values less than 55) induce a gradual rise in blood sugar levels. Regular intake of high-GI foods has the potential to cause insulin resistance, type 2 diabetes, and other metabolic conditions.

Dr. Shintani's method is a straightforward process: heat carbohydrate foods like rice, pasta, or potatoes, refrigerate them for several hours or overnight, and reheat them prior to eating. This process converts some of the digestible starches to resistant starches, which are not digested in the small intestine and thus are less likely to affect blood sugar levels.

The conversion to resistant starch happens in the cooling phase, a phenomenon called starch retrogradation. On cooling, amylose and amylopectin chains in starch rearrange to become less digestible. Heating them does not undo this modification, and so the resistant starch is preserved. Ingestion of resistant starch has been linked to increased insulin sensitivity, decreased blood sugar, and enhanced gut health.

1. Rice: White rice, cooked and subsequently cooled, has a GI of around 89, which can be lowered to around 53. Reheating after cooling preserves this lowered GI.^[1]

2. Pasta: Cooled, reheated Al dente pasta has a lower GI than recently cooked pasta.

3. Potatoes: Cooked potatoes allowed to cool overnight before reheating have a lowered GI, and they are thus a better choice for blood glucose control.

1. Add vinegar to your meals which can further lower the GI of foods by slowing gastric emptying. ^[2]

2. Opt for whole grains over refined grains, which will help in increasing fiber intake, which can help in moderating blood sugar levels. ^[3]

3. Incorporating healthy fats such as olive oil, nuts, seeds, or avocado can significantly slow the digestion and absorption of carbohydrates, leading to a steadier release of glucose into the bloodstream.

4. Lemon juice, and fermented foods like pickles or kimchi can reduce the glycemic response by increasing the acidity of the meal.

5. Gentle movement after meals—like a 10–15-minute walk—can significantly lower post-meal glucose levels.

Dr. Shintani's technique provides a convenient solution to minimizing the glycemic effect of carbohydrate foods without removing them from the diet. Simply changing the cooking method—cooking, cooling, and reheating—allows people to consume their favorite carbs while more effectively controlling their blood sugar levels. This method, in conjunction with other dietary techniques, can lead to better metabolic health and overall wellness.

References:

1. Singh, Shraddha. "Balancing Blood Sugar with Smart Carb Strategies." HealthifyMe, December 18, 2023. https://www.healthifyme.com/blog/smart-carb-strategies/.

2. Sattvic Foods. "Simple Hacks on How to Reduce Glycemic Index." Sattvic Foods, April 5, 2024. https://www.sattvicfoods.in/blogs/news/simple-hacks-on-how-to-reduce-glycemic-index.

3. Harvard Health Publishing. "Choosing Good Carbs with the Glycemic Index." Harvard Health Publishing, November 1, 2012. https://www.health.harvard.edu/staying-healthy/choosing-good-carbs-with-the-glycemic-index.

(Input from various sources)

(Rehash/Sakshi Thakar/MSM)