Cooking for Better Health: The Role of Culinary Strategies and Resistant Starch in Managing Type 2 Diabetes

By Sandra A. Farrell, Public Health Nutritionist.

Introduction

Starchy carbohydrates are often viewed as food foes, but one type known as resistant starch, has attracted attention, for providing better blood sugar control and a healthier gut microbiome. Resistant starch has health boosting properties of a prebiotic fibre, with benefits of a lower impact on blood sugar levels. Resistant starch is found in root vegetables, grains and legumes. Interestingly, some simple culinary techniques can boost the amount of resistant starch in pasta, rice, potatoes, oatmeal and other starchy foods that you eat.

Glycaemic index and glycaemic load explained

Carbohydrate-rich foods have properties that influence how quickly they are digested and how rapidly glucose (sugar) is released into the bloodstream. This is measured using a value, known as the glycaemic index (GI). Foods are ranked on a scale of 0 to 100 with pure glucose having a value of 100.

A separate measure, the glycaemic load, indicates the change in blood glucose level when someone eats a serving of food. It is calculated by multiplying the food’s GI by the amount of carbohydrate it contains.

According to Diabetes UK, choose foods that have a low or medium glycaemic load and limit those with a high glycaemic load.

Low glycaemic load: Apples, oranges, lentils, peas, kidney beans, black beans, raspberries, carrots, spinach and broccoli.

Medium glycaemic load: Brown rice, oatmeal, wholegrain bread, rice cakes, bulgur, whole-grain pasta and pearled barley.

High glycaemic load: White potatoes, candy bars, refined breakfast cereals, sugar sweetened beverages, white-flour pasta and white rice.

What is resistant starch?

True to its name, resistant starch resists digestion in the small intestine and travels mostly intact to the colon. Glucose tends to be absorbed more steadily and your blood sugar does not spike as high. Research suggests that increasing consumption of resistant starch, may lower sugar and insulin levels in people living with diabetes and obesity. Moreover, while in the colon, resistant starch becomes food for beneficial microorganisms in your microbiome, therefore contributing to your gut health, regulating blood sugar, among other health benefits.

Culinary Strategies to Reduce the Glycaemic Response from Starchy Food

Cook-and-cool technique: White potatoes contain regular starch and have a high glycaemic index. Mashed potatoes and French fries are popular ways to prepare potatoes, but you may want to consider potato salad as a replacement. Why? ‘’ If you leave potatoes in the refrigerator for one or two days, the cold temperature transforms some of the starch into resistant starch,’’ says Dr Frank Hu, professor of nutrition and epidemiology at the Harvard T.H. Chan School of Public Health.

To understand resistant starch further, when a starchy food is cooked, heat causes its starch granules to swell and become easier to digest. Importantly, if the cooked food is allowed to rest and chill (pasta and potato salad or overnight oats), the starch molecules reorganise into tighter structures through a process call retrogradation, in effect converting some of the starch to resistant starch. So cheers to leftover potatoes and pasta!

Oatmeal that has been pre-made and cooled in the fridge, builds resistant starch. Overnight oats can be topped up before consumption, with other ingredients that keep your blood sugar in check like berries and seeds.

Dressing: Add vinegar or incorporate pickled foods to meals rich in carbohydrates as the acid in vinegar or lemon juice, slows the conversion of starch to sugar in the body.

Cooking method: Boiling, steaming and microwaving can result in higher resistant starch content than deep-frying.

Cooking time: Research shows that cooking food for a longer time increases the glycaemic response. Therefore, short cooking times, such as pasta being cooked al dente (firm to the bite) will lead to a more controlled rise in glucose levels.

Prioritise under ripe fruits: Choose fruits at the right point of ripeness, rather than over-ripe. The starches in bananas change into simple sugars as they ripen. Green (unripe) bananas contain more resistant starch than ripe (yellow) bananas.

Food sequencing: Researchers have examined the impact of different foods on glycaemic response when eaten in a specific order. Consuming of protein, fat and fibre before starchy carbohydrates can slow gastric emptying and carbohydrate absorption, helping to reduce sharp rises in blood glucose after a meal.

About the Author

Sandra A Farrell is a UK based Public Health Nutritionist, Public Health Programme and Project Manager (Food and Nutrition), Health Coach, Educator and Mentor. Sandra is passionate about translating complex nutrition research into practical, everyday guidance, and sharing evidence-based nutrition information.

Disclaimer

The contents of this article, regardless of date is for educational purposes only and not intended to replace personalised medical advice from your doctor or healthcare professional.