Top 7 Health Benefits Of Eating Onions Backed By Research

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Onions are a root vegetable closely related to chives, leeks, and garlic. They belong to the Allium family of vegetables and are known to scientists as Allium cepa. Notably, onions are a versatile vegetable that is commonly eaten raw, fried, caramelized, sauteed, roasted, and beyond. Onions are characterized by a pungent flavor profile, come in an array of shapes and sizes, and most commonly come in red, yellow, and white varieties. Best of all, onions are packed with medicinal properties and health benefits that you may have never considered. Read on to see why you might hesitate to “hold the onions” in the future.

Important Note: All of the health benefits noted herein are supported by the most current scientific research at the time of this publication.

Packed With Antioxidants

Most notably, onions are loaded with powerful antioxidants that work hard to fight off the free radicals that could lead to chronic illnesses such as heart disease, diabetes, and some cancers. Onions are rife with antioxidants, containing more than 25 different types of disease-fighting compounds. They are especially dense in anthocyanins, a flavonoid that scientists have proven time and again to reduce the risk of heart disease. In fact, one study of more than 40,000 male subjects concluded that those who consumed an anthocyanin-rich diet experienced a 14% lower risk of heart disease. A similar study in women also concluded that women consuming an anthocyanin-rich diet had a 32% lower risk of experiencing a heart attack than those who didn’t have the same antioxidant intake. Considering onions are packed with these powerful antioxidants, it stands to both reason and science that eating onions can reduce these same risks. Lastly, anthocyanins, found in droves in onions, are also connected to a reduced risk for certain cancer types as well as diabetes.

General Consensus: 5/5 and here is why. Clearly, the powerful antioxidative prowess of onions makes them a good addition to your diet; eating this anthocyanin-rich food can help protect you against many chronic illnesses.

Full of Vital Nutrients

One of the best reasons to choose onions at mealtime is that they’re packed with many vitamins and minerals vital to your overall health. For starters, onions are remarkably high in vitamin C which is essential to immunity, the production of collagen, and iron absorption. Onions also contain high concentrations of vitamin B which is essential to red blood cell formation, healthy metabolism, and nerve functionality. Moreover, onions are an excellent source of potassium, delivering more than half the daily recommended value in just one serving. Potassium is integral to both kidney and muscle functions among other benefits. Finally, onions are quite low in calories making them a nutrient-dense vegetable; incredibly, an entire medium-sized onion contains only 44 calories.

General Consensus: 5/5 and here is why. Onions are fraught with high concentrations of many important vitamins and minerals; for this reason, incorporating this vegetable into your diet is highly recommended.

Good For Heart Health

Interestingly, eating onions may aid in your heart health. The antioxidative and anti-inflammatory properties contained in onions’ plant compounds are beneficial to heart health. Specifically, they lower triglycerides and cholesterol levels which in turn lower the risk for cardiovascular disease. One specific antioxidant, a flavonoid known as quercetin, is found in high concentrations in onions; quercetin is linked to lowering blood pressure which subsequently leads to a reduced risk of heart disease. In fact, one study showed that individuals who regularly consumed a quercetin-rich onion extract experienced a significant reduction in blood pressure when compared to those who didn’t consume the same onion extract. Another risk factor for heart disease is high cholesterol; one study of women showed that an onion-rich diet reduced bad cholesterol levels. Resultantly, consuming an onion-rich diet may lead to lower cholesterol levels which in turn reduces the risk for cardiovascular disease. Lastly, other studies in animals have drawn the same conclusions: an onion-rich diet lowers risk factors connected to heart disease.

General Consensus: 5/5 and here is why. Several scientific studies show a relationship between an onion-rich diet and a reduction in risk factors associated with cardiovascular disease.

Helps Fight Cancer

Onions contain two significant and powerful cancer-fighting compounds: allium and a sulfur-based plant compound. These two compounds have been scientifically linked to killing carcinogenic cells thereby inhibiting the growth and spread of cancer. Dozens of studies show that people who regularly eat allium vegetables were significantly less likely to receive a stomach cancer diagnosis than individuals not eating these veggies. Other similar studies conclude that subjects with an allium-rich diet were much less likely to have a colorectal cancer diagnosis than subjects not eating allium. What’s more, onions are fraught with vitamin A, a plant compound containing sulfur, which has been shown to inhibit tumor growth and slow the spread of certain cancer types. Lastly, onions carry the flavonoids fisetin and quercetin; these antioxidants are also known to slow and in some cases even stop the growth of cancerous tumors.

General Consensus: 5/5 and here is why. Several reputable studies boast the conclusion that onions contain powerful antioxidants that can inhibit and even prevent the proliferation of cancer.

Helps Manage Blood Sugar

If you’re someone living with diabetes or pre-diabetes, you know how important wise food choices are. Inevitably, diet is a useful way to manage diabetes and blood sugar levels. Not all foods are created equal so choosing foods with low carbohydrate content and a low glycemic index score is imperative. Onions meet both these goals, containing zero carbohydrates and scoring very low on the glycemic index. What’s more, one study showed that by eating a serving of fresh onions, subjects with diabetes were able to significantly lower existing high blood sugar. Other notable animal studies draw the same conclusion that eating fresh onions can actually remediate high blood sugar levels. Lastly, the sulfur compounds and quercetin contained in onions have uniquely anti-diabetic properties; together, they interact with multiple organs such as the pancreas to reduce high blood sugar levels.

General Consensus: 5/5 and here is why. Doubtful though it may seem, onions have been proven in several scientific studies to quell high sugar levels in diabetics and pre-diabetics.

Improves Bone Density

Another benefit of eating onions is that they may improve your bone density. The powerful antioxidants in onions are credited with a positive effect on bone health. Studies have shown that a daily serving of onion juice not only improves bone density, but it does so while reducing the risk for bone fractures. The theory is that the antioxidants in onions reduce the oxidative stress within the bones thereby strengthening their integrity.

General Consensus: 3/5 and here is why. Although there are only a few studies precisely studying the connection between onions and bone strength, they make emphatic claims.

Good For Digestive Health

Some studies suggest that an onion-rich diet may even be good for digestive health. The reason for the positive effect on digestion is that onions are rife with fiber and prebiotics that both feed the good gut bacteria and make for healthier bowel movements. Furthermore, the prebiotics enhance the growth of probiotics which leads to better digestion. Moreover, the short-chain fatty acids found in onions are good for optimal gut health as well as enhanced digestion.

General Consensus: 5/5 and here is why. Onions are a hearty source of prebiotics which ultimately improve digestion.

Unlikely Benefits: Further Research Needed

May Reduce Cholesterol

General Consensus: 2.5/5 and here is why. Although there are compelling studies suggesting that a serving per day of onions can have an overwhelming effect on cholesterol, there are only a handful of studies that draw this conclusion; more research is needed.

Good For Skin and Hair

General Consensus: 2/5 and here is why. While the vitamins A and E found in onions have been scientifically linked to hair and skin health, there’s simply not a high enough concentration in a serving of onions to be beneficial in and of itself.


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