In This ArticleView AllIn This ArticleNutrition FactsHealth BenefitsPotential DownsidesBest Ways to Enjoy ThemFAQs
In This ArticleView All
View All
In This Article
Nutrition Facts
Health Benefits
Potential Downsides
Best Ways to Enjoy Them
FAQs
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Photo:Jacob Fox
Jacob Fox
Including the humble onion in your daily meals might not sound like your conventional path to wellness. However, it actually offers some impressive benefits. Adding onion to your dishes doesn’t just give them a zesty kick; it also positively impacts your health.
If you love onions and wonder what happens to your body when you eat these pungent veggies, get ready to cry tears of joy. This article will peel back the layers of what eating onions means for your health and wellness.
Shallots vs. Onions: What’s the Difference?
Onion Nutrition Facts
Onions are a natural source of vitamins, minerals and plant compounds wrapped in a tasty package with many layers. While onions come in different varieties (think yellow, red and even a sweet Vidalia) and may vary in flavor and culinary applications, they are all similar in their nutritional composition. However, some have extra-impressive features that we will get into later.
Health Benefits of Onions
If you add onions to your dishes regularly, here are some effects you may observe.
May Support a Healthy Gut
Onions are a naturalsource of prebiotics, which are necessary for optimal gut health. Prebiotics are non-digestible fibers that serve as food for the beneficial gut bacteria, promoting their growth and encouraging a balanced gut flora.
Specifically, onions contain the prebiotic inulin, which helps stimulate the growth of healthy bacteria.Evidence suggests that allicin, a compound found in onion, may also help support a healthy gut, but more quality human-based data is needed to confirm this.
May Improve Your Heart Health
Regular consumption of onions also supports heart health. Onions contain anti-inflammatory and antioxidant properties, especially quercetin, that may have antihypertensive effects. Additionally, quercetin has been shown to help decrease triglycerides and reduce cholesterol levels. Evidence suggests that eating onion can not only be helpful in preventing and treating dyslipidemia and high blood pressure but ultimately may help reduce the risk of developing cardiovascular disease.
Might Benefit Your Eye Health
Onions are also helpful for supporting good eye health. They are rich in sulfur, which is important for producing glutathione, one of the body’s most potent antioxidants. This antioxidant, in particular, is necessary for the eyes' health, helping to prevent age-related macular degeneration, cataracts and glaucoma.Therefore, incorporating onions into your diet can potentially support and maintain good eye health.
Might Reduce Your Risk of Certain Cancers
Notably, onions may also contribute significantly to cancer prevention. They are rich in antioxidants and sulfur-containing compounds that may potentially reduce the risk of certain types of cancer, including lung, prostate and stomach.
One study assessed primary breast cancer cases among a sample of women in Puerto Rico. Results of the study suggest that high onion and garlic consumption may be protective against breast cancer among this population.Other data has shown that there may be a link between eating more foods that contain allicin, like onions, and a reduced risk of stomach cancer.That said, more robust research is needed to confirm these findings.
Have Antibacterial Properties
Onions may also have antibacterial properties to help fight off dangerous bacteria and reduce infections. Research suggests that onion essential oils could help reduce bacteria such asStaphylococcus aureusandSalmonella.
Despite the myriad benefits of consuming onions, they may not be suitable for everyone. Here are some potential downsides to eating onions regularly.
May Cause Digestive Discomfort
The presence of fructans, a type of complex carbohydrate, can trigger digestive discomfort in some individuals. These compounds can cause bloating, flatulence and stomach cramps, particularly in those withirritable bowel syndrome(IBS) or other sensitivities to FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols). Consequently, while onions are generally a beneficial addition to most diets, individuals with digestive conditions may need to limit their intake or opt for cooked onions, which are often better tolerated.
May Cause Allergic Reactions
While cases are rare, onions can trigger allergic reactions in certain people. Symptoms may range from mild, such as itching or rash, to severe, like breathing difficulties or anaphylaxis.Therefore, those with known onion allergies need to do some homework to make sure they eat safe dishes with no onions included. And if you think you might have an allergy to onions, speak with your health care provider.
May Cause a Bad Breath
Another drawback to consuming onions is their potential impact on breath odor. Due to their high sulfur content, onions can cause bad breath, or halitosis, which may persist for several hours after consumption. This can pose social discomforts and may require individuals to employ techniques such as proper oral hygiene or breath-freshening products to counteract the effects.
Best Ways to Cook and Enjoy Onions
Onions can be a delicious addition to your dishes. And thankfully, there are many interesting ways to cook and enjoy them.
Caramelized
Roasted
Roasting is another fantastic way to prepare and savor onions. This cooking method highlights onions' natural sweetness and imparts a delightful, toasty flavor. To roast onions, first preheat your oven to 400°F. Meanwhile, peel and quarter the onions. Toss them in a mix of olive oil, salt and pepper, then arrange them in a single layer on a baking sheet. Roast for about 25 to 30 minutes, or until the onions are tender and have developed a deep, golden brown color. Roasted onions pair wonderfully with roasted meats, or try them in salads or as a flavorful addition to a cheese board. Enjoy this simple yet satisfying way of cooking onions. OurMelting Onionsare a mouthwatering way to enjoy roasted onions.
Grilled
Grilling onions is yet another excellent method to unlock their flavor potential. The grill’s high heat chars the onions' outside, giving them a smoky taste, while the inside becomes tender and sweet. To grill onions, peel them and cut them into half-inch rounds. Then, brush both sides with olive oil and season with salt and pepper. Arrange the rounds on a preheated grill over medium heat. Grill them for about 4 to 5 minutes on each side, or until they have prominent grill marks and have softened. These grilled onions serve as a perfect condiment for meats or as an addition to summer salads. This method offers an easy, flavorful and healthful way to enjoy onions.
Raw
Our Best Onion Recipes
Caramelized Balsamic OnionsCaramelized Onion & Goat Cheese ToastCheesy Vegetarian Stuffed OnionsFrench Onion QuesadillaSlow-Cooker French Onion Soup with Gruyère Toasts
Caramelized Balsamic OnionsCaramelized Onion & Goat Cheese ToastCheesy Vegetarian Stuffed Onions
Caramelized Balsamic Onions
Caramelized Onion & Goat Cheese Toast
Cheesy Vegetarian Stuffed Onions
French Onion QuesadillaSlow-Cooker French Onion Soup with Gruyère Toasts
French Onion Quesadilla
Slow-Cooker French Onion Soup with Gruyère Toasts
Are Cut, Raw Onions Poisonous?
Frequently Asked Questions
Can You Eat Onions Every Day?
Consuming onions daily can be beneficial, due to their rich nutrient content and numerous health properties. However, they may cause digestive discomfort to certain people, especially those with digestive issues.
Are Onions Healthier Raw or Cooked?
Both raw and cooked onions have health benefits, though these can vary. Raw onions retain their full complement of vitamins and antioxidants, making them a slightly healthier option if you’re looking to maximize your intake of nutrients. However, cooking onions can break down some of their hard-to-digest fibers, making them easier for some people to eat.
Are Onions a Superfood?
Given their rich, nutrient-dense profile and numerous health benefits, one could argue that onions could be classified as a “superfood.” However, it’s important to remember that “superfood” is not a scientific term but a marketing term, and no single food, not even onions, can provide all the nutrition our bodies need.
Which Organs Benefit Most from Onions?
The Bottom Line
So, are onions the unsung heroes of the produce aisle, effortlessly boosting our health with every crunch? It would seem so. Their unique blend of nutrients and potent antioxidants gives them a well-deserved spot in our daily diets. But don’t ditch your apples and broccoli just yet. Remember, in the concert of good nutrition, onions may play a stellar solo, but the symphony of varied fruits, vegetables, whole grains and lean proteins makes the music of a healthy body. So, enjoy those onions, but make sure they share the stage with plenty of other nutritious foods, too.
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SourcesEatingWell uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable and trustworthy.U.S. Department of Agriculture FoodData Central.Onions, yellow, raw.U.S. Department of Agriculture FoodData Central.Onions, red, raw.U.S. Department of Agriculture FoodData Central.Onions, white, raw.Qin Y-Q, Wang L-Y, Yang X-Y, et al.Inulin: Properties and health benefits.Food & Function. 2023;14(7):2948-2968. doi:10.1039/d2fo01096hYuan Y, Lu L, Bo N, Chaoyue Y, Haiyang Y.Allicin ameliorates intestinal barrier damage via microbiota-regulated short-chain fatty acids-TLR4/MYD88/NF-ΚB cascade response in acrylamide-induced rats.Journal of Agricultural and Food Chemistry. 2021;69(43):12837-12852. doi:10.1021/acs.jafc.1c05014Dabeek WM, Marra MV. Dietary quercetin and Kaempferol:Bioavailability and potential cardiovascular-related bioactivity in humans.Nutrients. 2019;11(10):2288. doi:10.3390/nu11102288Galavi A, Hosseinzadeh H, Razavi BM.The effects of Allium cepa L. (onion) and its active constituents on metabolic syndrome: A review.Iran J Basic Med Sci. 2021;24(1):3-16. doi:10.22038/ijbms.2020.46956.10843Sreekumar PG, Ferrington DA, Kannan R.Glutathione metabolism and the novel role of mitochondrial GSH in retinal degeneration.Antioxidants. 2021;10(5):661. doi:10.3390/antiox10050661Desai G, Schelske-Santos M, Nazario CM, et al.Onion and garlic intake and breast cancer, a case-control study in Puerto Rico.Nutrition and Cancer.2019;72(5):791-800. doi:10.1080/01635581.2019.1651349Dalmartello M, Turati F, Zhang Z-F, et al.Allium vegetables intake and the risk of gastric cancer in the stomach cancer pooling (STOP) project.British Journal of Cancer. 2022;126(12):1755-1764. doi:10.1038/s41416-022-01750-5Chakraborty AJ, Uddin TM, Matin Zidan BMR, et al.Allium cepa: a treasure of bioactive phytochemicals with prospective health benefits. Garg R, ed.Evidence-Based Complementary and Alternative Medicine. 2022;2022:1-27. doi:10.1155/2022/4586318Albanesi M, Pasculli C, Giliberti L, et al.Immunological characterization of onion (Allium cepa) allergy.Postepy Dermatol Alergol. 2019;36(1):98-103. doi:10.5114/ada.2019.82829
Sources
EatingWell uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable and trustworthy.U.S. Department of Agriculture FoodData Central.Onions, yellow, raw.U.S. Department of Agriculture FoodData Central.Onions, red, raw.U.S. Department of Agriculture FoodData Central.Onions, white, raw.Qin Y-Q, Wang L-Y, Yang X-Y, et al.Inulin: Properties and health benefits.Food & Function. 2023;14(7):2948-2968. doi:10.1039/d2fo01096hYuan Y, Lu L, Bo N, Chaoyue Y, Haiyang Y.Allicin ameliorates intestinal barrier damage via microbiota-regulated short-chain fatty acids-TLR4/MYD88/NF-ΚB cascade response in acrylamide-induced rats.Journal of Agricultural and Food Chemistry. 2021;69(43):12837-12852. doi:10.1021/acs.jafc.1c05014Dabeek WM, Marra MV. Dietary quercetin and Kaempferol:Bioavailability and potential cardiovascular-related bioactivity in humans.Nutrients. 2019;11(10):2288. doi:10.3390/nu11102288Galavi A, Hosseinzadeh H, Razavi BM.The effects of Allium cepa L. (onion) and its active constituents on metabolic syndrome: A review.Iran J Basic Med Sci. 2021;24(1):3-16. doi:10.22038/ijbms.2020.46956.10843Sreekumar PG, Ferrington DA, Kannan R.Glutathione metabolism and the novel role of mitochondrial GSH in retinal degeneration.Antioxidants. 2021;10(5):661. doi:10.3390/antiox10050661Desai G, Schelske-Santos M, Nazario CM, et al.Onion and garlic intake and breast cancer, a case-control study in Puerto Rico.Nutrition and Cancer.2019;72(5):791-800. doi:10.1080/01635581.2019.1651349Dalmartello M, Turati F, Zhang Z-F, et al.Allium vegetables intake and the risk of gastric cancer in the stomach cancer pooling (STOP) project.British Journal of Cancer. 2022;126(12):1755-1764. doi:10.1038/s41416-022-01750-5Chakraborty AJ, Uddin TM, Matin Zidan BMR, et al.Allium cepa: a treasure of bioactive phytochemicals with prospective health benefits. Garg R, ed.Evidence-Based Complementary and Alternative Medicine. 2022;2022:1-27. doi:10.1155/2022/4586318Albanesi M, Pasculli C, Giliberti L, et al.Immunological characterization of onion (Allium cepa) allergy.Postepy Dermatol Alergol. 2019;36(1):98-103. doi:10.5114/ada.2019.82829
EatingWell uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable and trustworthy.
U.S. Department of Agriculture FoodData Central.Onions, yellow, raw.U.S. Department of Agriculture FoodData Central.Onions, red, raw.U.S. Department of Agriculture FoodData Central.Onions, white, raw.Qin Y-Q, Wang L-Y, Yang X-Y, et al.Inulin: Properties and health benefits.Food & Function. 2023;14(7):2948-2968. doi:10.1039/d2fo01096hYuan Y, Lu L, Bo N, Chaoyue Y, Haiyang Y.Allicin ameliorates intestinal barrier damage via microbiota-regulated short-chain fatty acids-TLR4/MYD88/NF-ΚB cascade response in acrylamide-induced rats.Journal of Agricultural and Food Chemistry. 2021;69(43):12837-12852. doi:10.1021/acs.jafc.1c05014Dabeek WM, Marra MV. Dietary quercetin and Kaempferol:Bioavailability and potential cardiovascular-related bioactivity in humans.Nutrients. 2019;11(10):2288. doi:10.3390/nu11102288Galavi A, Hosseinzadeh H, Razavi BM.The effects of Allium cepa L. (onion) and its active constituents on metabolic syndrome: A review.Iran J Basic Med Sci. 2021;24(1):3-16. doi:10.22038/ijbms.2020.46956.10843Sreekumar PG, Ferrington DA, Kannan R.Glutathione metabolism and the novel role of mitochondrial GSH in retinal degeneration.Antioxidants. 2021;10(5):661. doi:10.3390/antiox10050661Desai G, Schelske-Santos M, Nazario CM, et al.Onion and garlic intake and breast cancer, a case-control study in Puerto Rico.Nutrition and Cancer.2019;72(5):791-800. doi:10.1080/01635581.2019.1651349Dalmartello M, Turati F, Zhang Z-F, et al.Allium vegetables intake and the risk of gastric cancer in the stomach cancer pooling (STOP) project.British Journal of Cancer. 2022;126(12):1755-1764. doi:10.1038/s41416-022-01750-5Chakraborty AJ, Uddin TM, Matin Zidan BMR, et al.Allium cepa: a treasure of bioactive phytochemicals with prospective health benefits. Garg R, ed.Evidence-Based Complementary and Alternative Medicine. 2022;2022:1-27. doi:10.1155/2022/4586318Albanesi M, Pasculli C, Giliberti L, et al.Immunological characterization of onion (Allium cepa) allergy.Postepy Dermatol Alergol. 2019;36(1):98-103. doi:10.5114/ada.2019.82829
U.S. Department of Agriculture FoodData Central.Onions, yellow, raw.
U.S. Department of Agriculture FoodData Central.Onions, red, raw.
U.S. Department of Agriculture FoodData Central.Onions, white, raw.
Qin Y-Q, Wang L-Y, Yang X-Y, et al.Inulin: Properties and health benefits.Food & Function. 2023;14(7):2948-2968. doi:10.1039/d2fo01096h
Yuan Y, Lu L, Bo N, Chaoyue Y, Haiyang Y.Allicin ameliorates intestinal barrier damage via microbiota-regulated short-chain fatty acids-TLR4/MYD88/NF-ΚB cascade response in acrylamide-induced rats.Journal of Agricultural and Food Chemistry. 2021;69(43):12837-12852. doi:10.1021/acs.jafc.1c05014
Dabeek WM, Marra MV. Dietary quercetin and Kaempferol:Bioavailability and potential cardiovascular-related bioactivity in humans.Nutrients. 2019;11(10):2288. doi:10.3390/nu11102288
Galavi A, Hosseinzadeh H, Razavi BM.The effects of Allium cepa L. (onion) and its active constituents on metabolic syndrome: A review.Iran J Basic Med Sci. 2021;24(1):3-16. doi:10.22038/ijbms.2020.46956.10843
Sreekumar PG, Ferrington DA, Kannan R.Glutathione metabolism and the novel role of mitochondrial GSH in retinal degeneration.Antioxidants. 2021;10(5):661. doi:10.3390/antiox10050661
Desai G, Schelske-Santos M, Nazario CM, et al.Onion and garlic intake and breast cancer, a case-control study in Puerto Rico.Nutrition and Cancer.2019;72(5):791-800. doi:10.1080/01635581.2019.1651349
Dalmartello M, Turati F, Zhang Z-F, et al.Allium vegetables intake and the risk of gastric cancer in the stomach cancer pooling (STOP) project.British Journal of Cancer. 2022;126(12):1755-1764. doi:10.1038/s41416-022-01750-5
Chakraborty AJ, Uddin TM, Matin Zidan BMR, et al.Allium cepa: a treasure of bioactive phytochemicals with prospective health benefits. Garg R, ed.Evidence-Based Complementary and Alternative Medicine. 2022;2022:1-27. doi:10.1155/2022/4586318
Albanesi M, Pasculli C, Giliberti L, et al.Immunological characterization of onion (Allium cepa) allergy.Postepy Dermatol Alergol. 2019;36(1):98-103. doi:10.5114/ada.2019.82829
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