Onions are a staple ingredient in many dishes known for their distinct flavor and aroma. They add flavor and nutrition to a wide variety of dishes, from soups and stews to salads and sandwiches. Onions are also known for their potential health benefits, including reducing inflammation and improving heart health.

There are several different types of onions, including white, yellow, red, and green onions. Each type has its own unique flavor and nutritional profile. Some onions are higher in sugar and carbohydrates than others, which can affect blood sugar levels and insulin sensitivity in people with diabetes. Therefore, it is important to know which onions are best for diabetes.

For people with diabetes, choosing the right foods is crucial in managing their blood sugar levels. Onions are generally considered safe for people with diabetes to eat, but some types of onions may be better than others. This article explores which onion is best for diabetes and how it can benefit people with this condition.

What is Diabetes?

Diabetes is a chronic disease that affects how the body processes blood sugar (glucose). Glucose is a vital source of energy for the body's cells, but it needs insulin to enter the cells. Insulin is a hormone produced by the pancreas that helps regulate blood sugar levels. In people with diabetes, their body either does not produce enough insulin or cannot use it effectively, leading to high blood sugar levels.

There are two main types of diabetes:

Type 1 Diabetes

 Type 1 diabetes is an autoimmune disease where the body's immune system attacks and destroys the cells in the pancreas that produce insulin. This type of diabetes usually develops in children and young adults, and they require insulin injections to manage their blood sugar levels.

Type 2 Diabetes

Type 2 diabetes is the most common type and usually develops in adults. It occurs when the body becomes resistant to insulin or does not produce enough insulin to regulate blood sugar levels. Type 2 diabetes can often be managed through lifestyle changes such as diet and exercise, but some people may require medication or insulin injections.

Other types of diabetes include gestational diabetes, which occurs during pregnancy and usually goes away after delivery, and prediabetes, which is a condition where blood sugar levels are higher than normal but not high enough to be diagnosed as type 2 diabetes. Prediabetes can often be reversed through lifestyle changes.

Can Diabetics Eat Onions?

Research suggests that some onions may have more health benefits for people with diabetes than others. For example, red onions have been found to contain higher levels of certain antioxidants and flavonoids that may help lower blood sugar and improve insulin resistance. Meanwhile, green onions (also known as scallions) are lower in carbohydrates and calories than other types of onions, making them a good choice for people with diabetes who are watching their weight and blood sugar levels.

Onions have been used traditionally to treat diabetes, and recent studies suggest that they may positively impact blood sugar control. Onions are a low-calorie, healthful food to include in a diabetes diet, providing fiber, iron, potassium, vitamin C, and other micronutrients.

Animal studies suggest that onion extracts may help reduce high blood glucose levels, and onions have been shown to have antidiabetic effects and reduce cardiovascular disease.

One possible reason for onions' antidiabetic effects is their high content of flavonoids and sulfur compounds. Flavonoids have been shown to have anti-inflammatory, antioxidant, and antidiabetic effects, while sulfur compounds may help improve insulin sensitivity.

When incorporating onions into a diabetes diet, it is important to consider the carbohydrate content. While onions are low in calories, they do contain carbohydrates, and people with diabetes should monitor their carbohydrate intake to manage blood sugar levels. One medium onion contains about 11 grams of carbohydrates, so it is important to include onions in moderation and balance them with other non-starchy vegetables and lean proteins.

The Different Types of Onions

Onions come in various types and colors, and each type has its own unique flavor and nutritional profile. Here are some of the most common types of onions:

Yellow Onions

Yellow onions are the most commonly used onions in cooking. They have a strong flavor and a slightly sweet taste. They are also the best low-carb option for people with diabetes, as they have the lowest amount of sugar and total carbohydrates. A cup of chopped yellow onion contains around 7g of carbohydrates and just 1g of dietary fiber. Of the 6 grams of net carbs in a yellow onion, just 1g comes from sugar.

Yellow Onions

Red Onions

Red onions are milder in taste than yellow onions and have a slightly sweet and tangy flavor. They are also a good source of antioxidants, which can help reduce inflammation in the body. However, they are slightly higher in carbs than yellow onions, with a cup of chopped red onion containing around 9g of carbohydrates and 1.5g of dietary fiber.

Red Onions

White Onions

White onions have a mild, slightly sweet taste and are often used in Mexican and Southwestern cuisine. They are slightly lower in carbs than red onions, with a cup of chopped white onion containing around 8g of carbohydrates and 1.5g of dietary fiber.

White Onions


Shallots have a mild, sweet taste and are often used in French cuisine. They are slightly lower in carbs than white onions, with a cup of chopped shallots containing around 7g of carbohydrates and 1.5g of dietary fiber.


Overall, all types of onions can be included in a diabetes diet in moderation. Yellow onions are the best low-carb option, while red and white onions are richer in antioxidants than other types. Shallots are a good option for those who prefer a milder taste.

Are Onions Good for Diabetics?

Onions are a popular vegetable that is used in many different types of cuisine. They are often used to add flavor to dishes, but they may also provide some health benefits. One of the benefits of onions is that they may be good for diabetics.

Onions are low in calories and carbohydrates, which makes them a good choice for people with diabetes who need to manage their blood sugar levels. They also contain fiber, which can help slow down the absorption of sugar in the body.

This can help prevent blood sugar spikes and crashes. Research has shown that certain chemicals in onions, such as quercetin and sulfur compounds, may also help improve blood sugar control. These compounds may help increase insulin sensitivity, which can help the body use insulin more effectively.

Different types of onions may have different effects on blood sugar levels. For example, red onions may be more effective at lowering blood sugar levels than white onions. This is because red onions contain more quercetin than white onions. 

Effects of Onions on Diabetes

Health Benefits Of Onions

Onions and Blood Sugar Levels

Onions are a low-calorie, nutrient-dense food that can be a beneficial addition to a diabetes diet. They contain fiber, iron, potassium, vitamin C, and other micronutrients. Some evidence suggests that certain chemicals in onions may help maintain blood sugar control. Onion extract can reduce fasting blood sugar levels in people with type 1 diabetes and improved glucose tolerance in people with type 2 diabetes.

Onions and Insulin Sensitivity

Insulin resistance is a common problem in people with type 2 diabetes, where the body becomes less responsive to insulin. Onions may help improve insulin sensitivity, which can lead to better blood sugar control.

A study published in the Journal of Ethnopharmacology found that onion juice improved insulin sensitivity in rats with diabetes. Another study published in the International Journal of Food Sciences and Nutrition found that consuming onions improved insulin sensitivity in overweight and obese women with polycystic ovary syndrome (PCOS), a condition associated with insulin resistance. 

Which Onions are Best for Diabetics?

Onions are a great addition to any diet, especially for individuals with diabetes. But which onion is best for diabetes? There are a few factors to consider when answering this question.

Factors to Consider

One factor to consider is the type of onion. According to HealthReporter , white, yellow, and red onions are all beneficial for individuals with diabetes. However, red onions may have an edge over other types of onions due to their higher antioxidant content. Antioxidants can help reduce inflammation, which is an underlying cause of diabetes as well as many other metabolic issues.

Another factor to consider is the method of preparation. According to Livestrong, cooking onions can actually increase their hypoglycemic effect. This is because cooking onions releases more of the sulfur compounds that are responsible for lowering blood sugar levels.

Comparing the Glycemic Index of Onions

One way to determine the impact of onions on blood sugar levels is by comparing their glycemic index (GI). The GI measures how quickly foods raise blood sugar levels on a scale of 0 to 100. The higher the number, the faster the food raises blood sugar levels.

The GI of onions ranges from 10 to 15, which is considered a low glycemic index. This means that onions are unlikely to cause a significant spike in blood sugar levels, making them a suitable addition to a diabetes-friendly diet.

Comparing the Nutritional Content of Onions

Apart from the low glycemic index, onions also differ in their nutritional content. For instance, sweet onions are known for their mild taste and low sulfur content, while red onions are known for their sharp taste and high antioxidant content.

In terms of nutritional content, onions are low in calories and high in fiber, which can help regulate blood sugar levels. Onions also contain vitamins C and B6, folate, and potassium.

Research Studies

Research studies have shown that onions can have a positive effect on blood sugar levels. Onions have been shown to have antidiabetic effects as well as reduce cardiovascular disease. Onions seem to lower blood sugar in animal studies and have even been shown to do so in one human study.

The National Library of Medicine reported that preliminary research indicates that onions may have a hypoglycemic effect for people with diabetes. The authors of the article note that the sulfur compounds in onions, namely S-methylcysteine and the flavonoid quercetin, may be responsible for the effects on blood sugar. However, more research is needed to confirm these findings.

Expert Opinions

Onions are a great food for individuals with diabetes. Onions contain antioxidants and vitamin C, which can help reduce inflammation and improve heart health. Onions are also rich in fiber, which can help regulate blood sugar levels.

Overall, when it comes to which onion is best for diabetes, the type of onion and method of preparation are important factors to consider. However, all types of onions can be beneficial for individuals with diabetes due to their positive effect on blood sugar levels.

How to Incorporate Onions into Your Diet

Onions can be a versatile and flavorful addition to any diet, and incorporating them into meals can be a simple way to reap their potential health benefits for diabetes. Here are some tips on how to add onions to your diet:

1. Add onions to salads

Raw onions can add a crunchy texture and a pungent flavor to any salad. Simply chop up some onions and sprinkle them on top of your favorite greens.

2. Use onions in soups and stews

Onions can be used as a base for many soups and stews. Simply sauté some onions in a pot with some oil until they are soft and translucent, and then add other ingredients such as broth, vegetables, and meats.

3. Use onions as a topping

Raw or cooked onions can be a delicious topping for many dishes, such as burgers, sandwiches, and tacos. Simply chop up some onions and add them to your favorite dish before serving.

4. Roast onion

Roasting onions can bring out their natural sweetness and add a caramelized flavor to any dish. Simply cut onions into wedges, drizzle them with some olive oil, and roast them in the oven until they are tender and browned.

5. Make onion rings

Onion rings can be a delicious and fun snack or side dish. Simply slice onions into rings, dip them in batter, and fry them until they are crispy and golden.

Remember to be mindful of portion sizes when incorporating onions into your diet, as they do contain carbohydrates that can affect blood sugar levels. According to the American Diabetes Association, one serving of onions is equal to one-half cup cooked or one cup raw.

Frequently Asked Questions

Is fresh onion good for diabetes?

Fresh onion, particularly sweet onions, can be included in a diabetes diet without causing a spike in blood sugar levels.

Which onions are the healthiest?

Red onions are considered particularly beneficial for people with diabetes due to their high levels of chromium, which helps regulate blood sugar levels.

Which onions are high in sugar?

There is no evidence that any type of onion is particularly high in sugar, and the sugar concentration in fresh sweet onions is not significantly higher than that in storage onions.


When it comes to managing diabetes, onions can be a great addition to a healthy and balanced diet. Both yellow and sweet onions have been shown to have antidiabetic effects and can help control blood sugar levels. Onions are also low in calories and carbohydrates, making them a great non-starchy vegetable option for those with diabetes.

While more research is needed to fully understand the benefits of onions for diabetes, current studies suggest that they can help reduce inflammation and improve insulin sensitivity. Onions also contain high levels of antioxidants, which help reduce oxidative stress in the body and can lead to healthy blood sugar levels.

It's important to note that onions should not be used as a substitute for medical treatment or a balanced diet. Consult with a healthcare professional or registered dietitian to determine how onions can fit into your individual diabetes management plan.

Overall, incorporating onions into a healthy and balanced diet can be a great way to support diabetes management. Whether you prefer yellow or sweet onions, both can provide valuable health benefits and help regulate blood sugar levels.


At Diabetic Me, we are committed to delivering information that is precise, accurate, and pertinent. Our articles are supported by verified data from research papers, prestigious organizations, academic institutions, and medical associations to guarantee the integrity and relevance of the information we provide. You can learn more about our process and team on the about us page.

  1. Health Reporter Is Onion Good for Diabetes? Glycemic Index and Sugar Content
  2. Livestrong How to Use Onions to Lower Blood Sugar
  3. National Library of Medicine Flavonoids and Their Anti-Diabetic Effects: Cellular Mechanisms and Effects to Improve Blood Sugar Levels

About the Author

Inez Briand

Inez Briand is the partner of a type 1 diabetic (Ely). She has always been interested in traveling and cooking, and now that she has a partner with diabetes, her interest in cooking even more healthily has skyrocketed. She loves finding new recipes for her partner and family and sharing any food and nutrition-related articles on Diabetic & Me.

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