Incorporating a handful of chopped onions makes almost every savory dish taste even better. Spaghetti with meat sauce, a Mediterranean-inspired salad, stir-fry, tacos with fresh salsa, Indian curry … onions are a key ingredient in cultural dishes all around the world. Despite having a strong flavor, they’re extremely versatile. (Now, if only cutting them without tearing up was easier.) While you’re likely well-acquainted with how onions taste, you may not be as familiar with how, exactly, they benefit the body. Spoiler alert: There’s a lot of benefits to this veg. If the taste alone isn’t enough to inspire you to cook with onions more, the below eight health benefits just might convince you. You could say that there are many (ahem) layers to their perks.
8 health benefits of onions, according to registered dietitians
1. Regularly eating onions is good for your heart
According to Amy Gorin, MS, RDN, an inclusive plant-based dietitian and owner of Master the Media, one of the major benefits of eating onions regularly is that they are good for your heart. “Eating onions may help improve blood thinning and prevent the platelet aggregation that may contribute to stroke or heart attack,” she says. One scientific study found that drinking onion juice (um, yum?) was linked to lowering LDL cholesterol levels, another reason why onions are beneficial for heart health. Fortunately, other scientific studies have found that you can reap the same benefits by eating onions rather than drinking them.
2. Onions support brain health
Registered dietitian Shahzadi Devje, RD, says that onions are high in antioxidants, which benefit both the heart and brain. “Flavonoids, which are present in onions, have anti-inflammatory properties that help protect the body’s cells,” she says. This specific type of antioxidant has been linked to helping protect against neurological diseases, including Alzheimer’s and Parkinson’s. “The outer layers of the bulb have greater antioxidant activity than the inner layers, which is important because many folks typically throw the outer layers away,” Devje adds. Gorin says that onions contain another nutrient that’s crucial for brain health: quercetin. “ A study in Journal of Clinical Biochemistry and Nutrition found that older adults who ate Sarasara Gold onion bulbs—a type of onion with a high quercetin amount—for about six months experienced less age-related cognitive decline,” she says, adding that white onions don’t contain as much quercetin. “The researchers think this may be because the quercetin helped improve emotional conditions [such as mood and motivation],” Gorin says.
3. Eating onions helps support the immune system
When most people think of immunity-boosting foods, they think of citrus. But both experts say that onions contain vitamin C, making them beneficial for the immune system as well. One cup of chopped white onion contains about 12 milligrams of vitamin C. For adults, it’s recommended to get between 65 to 90 milligrams a day, so incorporating a serving of chopped onions into your meal is a nice drop in the bucket toward reaching your intake goal.
4. Onions benefit the skin
Devje points out that since onions contain vitamin C, they’re directly benefiting the skin. “Vitamin C is required for cellular growth and repair,” she says. “It also supports collagen production.” Collagen is what slows wrinkles from forming as quickly, so consuming onions regularly will help keep skin taut, working from the inside out.
5. They support digestive health
One cup of chopped onion contains about 3 grams of fiber, which Gorin says is beneficial for digestive health. “Fiber not only benefits cholesterol levels, but helps to keep you fuller for longer,” she says. Fiber also helps keep blood sugar levels from spiking, which keeps energy and mood balanced.
6. Onions contain protein
Gorin also says that a cup of chopped onions contains about 2 grams of protein. It’s not enough where you’ll want to make onions your primary source of protein, but every little bit counts. The protein content is another reason why the veggie is helpful for keeping blood sugar levels steady and making a meal more satiating.
7. Cooking with onions can enhance the health benefits of other foods
Onions aren’t typically eaten on their own, and Devje says this is definitely a positive, nutritionally speaking. “Onions and tomatoes have an interesting nutritional synergy, for example,” she says. “Combining onion with tomatoes has been found to boost the absorption of lycopene—a type of antioxidant—present in tomatoes.” Scientific researchers have also found that adding onions to foods made with whole grains or pulses (like beans and chickpeas) helped zinc and iron be better absorbed in the body. So cooking with onions helps make already healthy meals even healthier!
8. Regularly eating onions may help protect against certain kinds of cancer
Reserach has also connected regular onion consumption with a lower risk of certain types of cancer, specifically cancers of the gastrointestinal tract, including colon cancer. Researchers believe one reason for this is onions’ bioactive sulfur compounds. Certainly, the other benefits highlighted here play a role as well, including being high in antioxidants and containing other beneficial nutrients.
Tips for storing and cooking with onions
When it comes to storing onions properly, Gorin says it’s best to store onions in the crisper inside the fridge where they will last several months. “Once your onion is cut, you should store it in an airtight glass container in the fridge for up to a week,” she says, adding that diced onions can last even longer in the freezer—up to several months. Devje says that onions can also be stored in the pantry (before being cut open), but she specifies that they shouldn’t be kept next to potatoes. This is because onions produce a gas called ethylene, which potatoes are sensitive to and can cause them to spoil faster. In terms of cooking with onions, there’s no shortage of ways to incorporate them into your meals, but Devje says that some cooking methods will actually enhance the nutritional properties. “Research indicates that baking, grilling, and frying onions results in a higher amount of antioxidants, especially quercetin,” she says, adding that this is true for both red- and white-skin onions. It’s clear that the nutritional benefits of eating onions are just as varied as the ways of cooking with them. With a resume like the one listed above, they’re certainly worth your culinary attention. Sure, you may have to brush your teeth more often (onion breath may be the only downside to this veg), but the pros definitely outweigh the cons. Next up, here are 25 more foods that are good for your heart.
Sources:
Amy Gorin, MS, RDN, inclusive plant-based dietitian and owner of Master the MediaShahzadi Devje, RD, registered dietitian
