Understanding the Glycemic Index & How to Balance Blood Sugar Levels
When learning about nutrition, it is important to understand the glycemic index and how it affects your health. The glycemic index (or GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar (glucose) levels after eating. Foods with a high GI are those which are rapidly digested, absorbed and metabolized and result in marked fluctuations in blood sugar (glucose) levels. Low GI carbohydrates – the ones that produce smaller fluctuations in your blood glucose and insulin levels – is one of the secrets to long-term health, reducing your risk of type 2 diabetes and heart disease
Carbohydrates and the Glycemic Index
Carbohydrates are one of the main sources of energy for the body, and all carbohydrate foods affect our blood sugar in different ways. The glycemic index (GI) is a relative ranking of carbohydrate in foods according to how they affect blood glucose levels. Carbohydrates with a low GI value (55 or less) are more slowly digested, absorbed and metabolized and cause a lower and slower rise in blood glucose and therefore, usually insulin levels.
To get a better understanding of the glycemic index, let us first discuss what exactly carbohydrates are and how they are processed by the body.
Carbohydrates are the sugars, starches and fibers found in fruits, grains, vegetables and milk products. While many trendy diets will often criticize carbohydrates, they are actually one of the basic food groups—the others being fat, protein, vitamins, and minerals. They are called carbohydrates because, at the chemical level, they contain carbon, hydrogen and oxygen.
Carbohydrates are the most important source of energy for your body. Your digestive system changes carbohydrates into glucose (blood sugar), and then uses this sugar for energy for your cells, tissues and organs.
Once a food containing carbohydrates is consumed, the digestive system breaks down the digestible ones into sugar, which then enters the blood. As blood sugar levels rise, the pancreas produces insulin, a hormone that prompts cells to absorb blood sugar for energy or storage. As cells absorb blood sugar, levels in the bloodstream begin to fall. When this happens, the pancreas starts to make making glucagon, a hormone that signals the liver to start the release of stored sugar. This interplay of insulin and glucagon ensures that cells throughout the body, and especially in the brain, have a steady supply of blood sugar.
Carbohydrate metabolism is important in the development of type 2 diabetes, which occurs when the body can’t make enough insulin or can’t properly use the insulin that it makes. Type 2 diabetes usually develops gradually over a number of years, beginning when muscle and other cells stop responding to insulin. This condition, known as insulin resistance, causes blood sugar and insulin levels to stay high long after eating. Over time, the heavy demands made on the insulin-making cells wears them out, and insulin production eventually stops.
Simple & Complex Carbohydrates
In the past, carbohydrates were commonly classified as being either “simple” or “complex.” Simple carbohydrates are composed of sugars (such as fructose and glucose) which have simple chemical structures composed of only one sugar (monosaccharides) or two sugars (disaccharides). Simple carbohydrates are easily and quickly utilized for energy by the body because of their simple chemical structure, often leading to a faster rise in blood sugar and insulin secretion from the pancreas – which can have negative health effects.
Complex carbohydrates have more complex chemical structures, with three or more sugars linked together (known as oligosaccharides and polysaccharides). Many complex carbohydrate foods contain fiber, vitamins and minerals, and they take longer to digest – which means they have less of an immediate impact on blood sugar, causing it to rise more slowly.
Dividing carbohydrates into simple and complex, however, does not account for the effect of carbohydrates on blood sugar and chronic diseases. To explain how different kinds of carbohydrate-rich foods directly affect blood sugar, the glycemic index was developed and is considered a better way of categorizing carbohydrates, especially starchy foods.
The Glycemic Index
The glycemic index ranks carbohydrates on a scale from 0 to 100 based on how quickly and how much they raise blood sugar levels after eating. Foods with a high glycemic index, like white bread, are rapidly digested and cause substantial fluctuations in blood sugar. Foods with a low glycemic index, like whole oats, are digested more slowly, prompting a more gradual rise in blood sugar.
There are three classifications for Glycemic Index:
Individual food portion:
- Low: 55 or less
- Mid: 56 – 69
- High: 70+
Low-glycemic foods have a rating of 55 or less, and foods rated 70-100 are considered high-glycemic foods. Medium-level foods have a glycemic index of 56-69. Eating many high-glycemic-index foods – which cause significant spikes in blood sugar – can lead to an increased risk for type 2 diabetes, heart disease, and weight gain. There is also preliminary work linking high-glycemic diets to age-related macular degeneration, ovulatory infertility, and colorectal cancer.
Foods with a low glycemic index have been shown to help control type 2 diabetes and improve weight loss. A 2014 review of studies researching carbohydrate quality and chronic disease risk showed that low-glycemic-index diets may offer anti-inflammatory benefits.
Many factors can affect a food’s glycemic index. For example, grains that have been milled and refined—removing the bran and the germ—have a higher glycemic index than minimally processed whole grains. Finely ground grain is more rapidly digested than coarsely ground grain. Because of this, eating whole grains in their “whole form” like brown rice or oats can be healthier than eating highly processed whole grain bread.
High-fiber foods have a lower glycemic load, as they don’t contain as much digestible carbohydrate, so it slows the rate of digestion and causes a more gradual and lower rise in blood sugar.
Balancing Blood Sugar Levels
A diet rich in plant-based foods such as whole grains, healthy fats, fruits, vegetables, legumes, nuts, and seeds is a great way to help balance blood sugar levels and may help to reduce your risk of diabetes. Specific foods within these categories are especially beneficial in keeping your blood sugar in check.
Whole grains, especially oats and barley, are helpful for blood sugar levels because they are high in soluble fiber and are slower to digest than other carbohydrates. Slower digestion creates a smaller fluctuation in blood sugar compared with refined carbohydrates.
Non-starchy vegetables such as broccoli, green beans, spinach, kale and other leafy greens are recommended by diabetes experts to maintain healthy blood sugar levels. These vegetables are low in carbohydrates, high in dietary fiber and rich in magnesium. The National Institutes of Health reports that magnesium helps regulate blood sugar levels and promotes normal blood pressure. Starchy vegetables such as white potatoes, peas and corn should be consumed only in small amounts as they have the effect of raising blood sugar much more dramatically.
Legumes are a high-fiber, high-protein, complex carbohydrate with significant amounts of magnesium. The legume family includes black beans, pinto beans, garbanzo beans, soybeans, kidney beans and lentils, and many others. Substituting legumes for foods that are high in saturated fats or refined carbohydrates is a powerful step to help lower your risk of type 2 diabetes.
Nuts and seeds are another excellent source of magnesium. They are also high in protein, fiber and healthy fats.
Herbs & Supplements Noted for Balancing Blood Sugar
There are many herbs and supplements that are also well-known for their ability to balance blood sugar levels and be a great addition to your diet, for they often offer many other nutritional benefits as well.
Cinnamon, is one great example. One study on cinnamon, reported in the American Diabetes Association Journal, concludes that as little as one gram of cinnamon per day improves blood sugar, triglyceride, LDL cholesterol and total cholesterol in people with type 2 diabetes. Cinnamon is a spice loved by many, and is an easy one to add into a variety of meals. Cinnamon is typically grouped into two types—Ceylon and Cassia. Both are beneficial for balancing blood sugar levels, although Ceylon cinnamon is often preferred as it contains more antioxidants.
Bitter melon is another wonderful way to lower the body’s blood sugar. Bitter melon actually has properties that act like insulin, which helps bring glucose into the cells for energy. The consumption of bitter melon can help your cells utilize glucose and move it to your liver, muscles, and fat. The melon may also be able to help your body retain nutrients by blocking their conversion to glucose that ends up in your bloodstream. A study in the Journal of Ethnopharmacology compared the effectiveness of bitter melon with a current diabetes drug, concluding that bitter melon reduced fructosamine levels with type 2 diabetes participants.
Another herb well known for its ability to regulate blood sugar is nopal cactus. Nopal, also known as prickly pear, is famous for offering health benefits due to its high antioxidant, vitamin, and mineral content. Nopal cactus has long been used in traditional Mexican medicine for treating diabetes, and there is some preliminary clinical evidence to support its benefit. Single doses of nopal have been shown to decrease blood glucose levels by 17% to 46% in some patients.
The glycemic index is a way of understanding how different carbohydrate foods affect blood sugar levels in the body by ranking carbohydrates on a scale from 0 to 100 based on how quickly and how much they raise blood sugar levels after eating. Foods that rank lower on the GI (55 or less) are digested more slowly, prompting a more gradual rise in blood sugar, and have been shown to help control type 2 diabetes and improve weight loss. Foods that rank high on the GI (70+) are rapidly digested and cause substantial fluctuations in blood sugar, and over time this can lead to an increased risk for type 2 diabetes, heart disease, and weight gain.
Eating a diet rich in plant-based foods such as whole grains, healthy fats, fruits, vegetables, legumes, nuts, and seeds is a great way to help balance blood sugar levels and may help to reduce your risk of diabetes. Including specific herbs and supplements in your diet can also be a beneficial way to balance blood sugar levels in your body.
Understanding what carbohydrates are, where carbohydrate foods rank on the glycemic index, and how they influence your body, can empower you to make healthy decisions when choosing what to eat, which will support you in giving your body what it needs to thrive so that you can lead a healthy and balanced life.