The Glycemic Index and Health Benefits of Green Beans

Introduction

Green beans are a nutritious vegetable that can be a healthy addition to any diet. They are low in calories and rich in fiber, vitamins, minerals and antioxidants. One of the things that makes green beans so healthy is their low glycemic index.

The glycemic index (GI) is a ranking of carbohydrates based on their effect on blood glucose levels. Foods with a high GI raise blood sugar more quickly than foods with a low GI. Eating too many high GI foods on a regular basis can increase the risk of obesity, diabetes, heart disease and other chronic illnesses.

Green beans have a low GI, meaning they do not significantly spike blood sugar levels. This makes them an excellent choice for people with diabetes or prediabetes and those looking to manage their weight.

What is the Glycemic Index?

The glycemic index is a scale that ranks carbohydrate-containing foods based on how they impact blood glucose levels. It ranges from 0 to 100:

• Low GI: 55 or less
• Medium GI: 56-69
• High GI: 70 or more

Foods are tested by feeding set amounts to healthy participants and measuring their blood glucose response over a 2 hour period. The results are compared to the response to a control food, usually glucose or white bread.

Low GI foods cause a slower, smaller rise in blood sugar compared to high GI foods. They are digested and absorbed more slowly, resulting in a more gradual release of glucose into the bloodstream.

Benefits of Low GI Foods

Eating more low GI foods can provide the following benefits:

• Better blood sugar control
• Reduced insulin spikes
• Increased feeling of fullness
• Weight loss
• Reduced risk of heart disease and diabetes

Choosing low GI carbs leads to better blood sugar management. This helps prevent energy crashes, sugar cravings and overeating.

The Glycemic Index of Green Beans

Green beans have a low glycemic index, ranging from 22-40 on the GI scale depending on the variety. This makes them a diabetes-friendly, blood sugar friendly food.

For example, some common green bean GI values include:

• String beans, GI=22
• French beans, GI=32
• Wax beans, GI=38
• Runner beans, GI=40

This puts green beans in the same low GI category as other healthy foods like apples, berries, peas, lentils, nuts, seeds, quinoa, oats and brown rice.

The low carbohydrate and high fiber content of beans cause them to be slowly digested. This results in a steady, gradual rise in blood sugar rather than a sharp spike.

Fiber Content

Green beans are an excellent source of fiber, providing about 3 grams per cup cooked. The two main types of fiber are soluble and insoluble:

• Soluble fiber - dissolves in water to form a gel-like substance. It helps lower blood sugar, cholesterol and insulin levels.
• Insoluble fiber - does not dissolve or absorb water. It promotes regular bowel movements and healthy digestion.

Green beans contain both soluble and insoluble fiber, promoting gut health, digestive regularity, and metabolic health.

Low Glycemic Load

In addition to GI, another important concept is glycemic load (GL). GL accounts for the amount of carbohydrates in a serving of food, whereas GI only considers quality.

GL is calculated by multiplying a food's GI by the amount of carbohydrates per serving, then dividing by 100. Low GL foods cause smaller rises in blood sugar.

Green beans have a very low GL of only 2-7 per serving. This low GL makes them an excellent carb choice for blood sugar management.

Nutrition Profile of Green Beans

Green beans are packed with nutrients and antioxidants while being low in calories:

• 31 calories per 1 cup cooked
• 6 grams carbs
• 3 grams fiber
• 2 grams protein
• Vitamin C, K, A, B6, folate
• Manganese, iron, magnesium, potassium, calcium
• Carotenoids like beta carotene, lutein, violaxanthin
• Polyphenols like quercetin, kaempferol

Their vitamin, mineral and antioxidant content provide many health benefits beyond simply being low GI.

Protein

Beans are higher in protein than most other veggies. A 1 cup serving of green beans contains 2 grams of protein.

Although not a huge amount, this protein is high quality and helps enhance the fiber's appetite regulating effects. It's also beneficial for diabetics, since protein slows digestion and prevents blood sugar spikes.

Vitamins & Minerals

Green beans are an excellent source of:

• Vitamin C - antioxidants that boost immunity and synthesize collagen.
• Vitamin K - supports bone health and prevents calcium buildup in arteries.
• Folate - essential for cell growth and DNA production, especially important for pregnant women.
• Manganese - trace mineral that assists carbohydrate metabolism.
• Iron - carries oxygen in the blood to cells and tissues.

They also contain magnesium, potassium, calcium and vitamin A in smaller amounts.

Antioxidants

Green beans are rich in carotenoids like beta carotene and lutein. These antioxidants fight free radical damage and inflammation.

They also contain flavonoids like quercetin and kaempferol. These polyphenol antioxidants have anti-diabetic effects such as lowering blood sugar, protecting cells from oxidation, and decreasing inflammation.

Health Benefits of Green Beans

Some of the top health benefits of green beans include:

1. Regulate Blood Sugar

The fiber, protein, vitamins and antioxidants in green beans support healthy blood sugar regulation. The low GI prevents unhealthy spikes in glucose and insulin.

Studies show that low GI diets can decrease insulin resistance, sensitivity, and reduce levels of oxidative stress and inflammation in people with diabetes.

2. Aid Weight Loss

Green beans are low in calories and high in fiber. This makes them very filling without providing many calories.

Replacing high GI carbs with low GI options like beans has been shown to promote weight loss and reductions in body fat.

Increased fullness from the fiber can also reduce appetite and control overeating throughout the day.

3. Protect Heart Health

The nutrients in green beans help protect heart health in several ways:

• Fiber reduces LDL "bad" cholesterol.
• Potassium lowers blood pressure.
• Folate decreases homocysteine levels, a risk factor for heart disease.
• Antioxidants prevent oxidation of LDL cholesterol and inflammation of arteries.

Studies associate low GI diets with significant reductions in heart disease risk factors like LDL cholesterol and triglycerides.

4. Reduce Cancer Risk

The vitamin, mineral and antioxidant content of green beans may provide protection against various cancers:

• Fiber attaches to carcinogenic toxins and removes them.
• Carotenoids prevent cell mutation and tumor growth.
• Saponins inhibit spread of cancer cells.
• Folate is linked to reduced risk of lung, stomach, cervix and pancreas cancers.

Specific antioxidants in green beans like lutein and beta carotene are associated with lowered rates of breast and lung cancers.

5. Improve Digestion

The insoluble fiber in green beans acts as a bulking agent. It moves through the digestive tract intact, promoting regular bowel movements and preventing constipation.

Soluble fiber feeds the good bacteria in the gut microbiome. The antioxidants can also help decrease inflammation in the digestive tract.

6. Strengthen Bones

Green beans provide vitamin K, a critical nutrient for bone health. Vitamin K improves calcium absorption and reduces urinary excretion of calcium, preventing osteoporosis.

Just one cup of green beans provides over 30% of the RDI for vitamin K. Low intakes of vitamin K have been associated with a higher risk of bone fractures.

7. Enhance Immunity

The vitamin C, A and antioxidants in green beans support the immune system. Vitamin C stimulates white blood cell production and function, while carotenoids enhance the immune response.

Getting enough vitamin C and antioxidants can reduce the length and severity of respiratory infections like the common cold.

Ways to Eat Green Beans

There are many delicious ways to eat green beans:

• Saute, steam or boil then top with herbs, spices, olive oil or cheese.
• Roast with olive oil, salt and pepper in the oven.
• Add raw to salads for crunch and nutrition.
• Dip in hummus, ranch dressing or other dips.
• Stir fry with chicken or beef and Asian flavors.
• Add to soups, pasta dishes, tacos, omelets.
• Serve with almonds or other nuts for more protein.

Some easy green bean recipes include:

• Green bean casserole
• Garlic Parmesan green beans
• Maple toasted pecan green beans
• Sesame ginger green beans
• Bacon wrapped green beans

Selecting and Preparing Green Beans

Choosing the Best

Look for the following when buying green beans:

• Bright green color
• Firm with smooth skin
• No brown spots
• Crisp not limp
• Smaller beans have best texture

Storage

Store fresh green beans in a plastic bag in the refrigerator for 3-5 days. Rinse before using.

You can freeze beans for longer storage. Blanch for 1-2 minutes then freeze in an airtight container for 6-8 months.

Preparation

Rinse green beans under cool water. Snap off the stem ends. Leave whole or cut into smaller pieces if desired.

Steam, boil, saute or roast until the desired tenderness is reached, about 5 minutes for steaming.

When boiling green beans, use as little water possible to avoid losing nutrients. Do not overcook beans into a mushy consistency.

Risks and Precautions

Green beans are safe for most people but there are some considerations:

• Food allergies - Allergic reactions are possible, especially in those allergic to birch pollen.
• Kidney stones - Green beans contain oxalates. Those prone to stone formation may need to limit intake.
• Blood thinner medication - Large amounts of vitamin K can interfere with these medications. Monitor intake.

Otherwise, green beans make a nutritious addition to a low glycemic diet for better health.

The Bottom Line

Green beans have a very low glycemic index and glycemic load. This makes them an excellent food for regulating blood sugar and insulin levels.

They provide protein, fiber, vitamins, minerals and beneficial plant compounds for health. Nutrition alone does not determine a food's GI - factors like digestibility, starch structure and cooking method also matter.

Enjoy green beans prepared in a variety of healthy ways as part of a low glycemic eating pattern to manage blood sugar, maintain energy levels, control appetite and reduce disease risk.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.