Don’t Toss Those Onion Skins—They’re Actually More Nutritious Than You Think

It’s common for home cooks to remove and discard the outer skin of the onion before adding the vegetable to a dish, but that could mean missing out on many health benefits.

If you enjoy the taste, onion skins can be a great source of a number of anti-inflammatory nutrients, says Erin Palinski-Wade, RD, CPT, a registered dietitian and author based in New Jersey. Health.

“The outer skins of onions are nutritional powerhouses compared to the inner layers,” she said.

Here’s what you need to know about why onion skins can be so healthy and how to incorporate them into your cooking.

Yellow, red, and white onions all have top layers usually thin and light in color, although depending on when the onion was grown the skin can sometimes be multi-layered and darker in color.

They are usually thrown away, but vegetable and fruit byproducts like skins and peels are often rich in bioactive compounds, antioxidants and other nutrients. Onion skins are no exception.

“The key nutritional components of onion skins are fiber, certain minerals like calcium and zinc, and bioactive compounds like flavonoids,” said Megan Meyer, PhD, a communications consultant and nutritional immunology researcher based in North Carolina. Health.

Onion skins also contain vitamins A, C and E, Palinski-Wade added.

They can provide a boost of antioxidants

As Palinski-Wade mentioned, the outer layers of an onion are rich in antioxidants. In particular, red onion peels are a good source of a flavonoid called anthocyanin, while other peels are a good source of a flavonoid called quercetin.

Anthocyanins and quercetin can help eliminate disease-causing free radicals in the body, meaning they can support heart health, suppress inflammation, and reduce the risk of cancer, diabetes, and other diseases.

Flavonoids can be found in the rest of the onion, but in lower concentrations. In fact, onion skin powder can contain more than a dozen times more quercetin than the inner layers.

Because of these high levels of flavonoids and other antioxidants, researchers are studying whether onion peel extract (in capsules, for example) could improve health. Data suggests it may have antimicrobial and neuroprotective properties, as well as help protect against certain types of cancer, high blood sugar, high cholesterol, obesity and erectile dysfunction.

They can help you reach your fiber goals

Compared to the inner layers, onion skins contain the most dietary fiber, according to research.

Although the vast majority of Americans do not meet the recommended fiber intake, studies have linked a high-fiber diet to better bowel movements, more stable blood sugar, lower cholesterol, cancer prevention, greater satiety, and more.

They can help eliminate food waste

A major benefit of adding onion skins to your diet is that they can help you reduce food waste, Meyer said.

“In some countries, it is estimated that 300 to 500 kilograms of onion skin is wasted every day. In the United States, about 30 to 40 percent of the food supply is wasted,” she said. “So I love finding new ways to use all parts of a food.”

Beyond making changes to their own cooking, some groups are finding ways to add onion skins to other processed foods, which reduces waste and increases nutritional value.

“Specifically, a study using onion skin as an ingredient in enriched pasta found that it improved the nutritional properties of the pasta,” Meyer explained. “For this reason, onion skins have been incorporated into foods like gluten-free bread, wheat bread and meat patties.”

Onion skins are safe to use in small quantities, however, eating them raw is not recommended. That’s because they’re difficult to chew and can pose a choking hazard, Palinski-Wade explained.

They’re also harder to digest, she explained, “especially for those with sensitive stomachs or irritable bowel syndrome.”

It’s true that the added fiber from onion skins can be good for digestion, Meyer noted, but it’s important to start small and see how your body responds.

Another potential risk? Pesticide residue, Palinski-Wade said. For this reason, she recommends choosing organic onions or washing the skin well.

Onions have also been the subject of a number of food recalls recently, and the outer layers are more likely to be contaminated with bacteria. While there’s not much you can do, Meyer said it’s important to handle food safely, which follows four steps: clean, separate, cook and refrigerate.

One of the easiest ways to use onion skins in cooking is to add them to a big batch of vegetable or chicken broth, Meyer suggested. “You can also simmer onion skins in soups or stews to increase the depth of flavor,” she said.

Don’t forget to drain the skins before serving.

“Another fun option is to dry and grind the clean skins into a fine powder to use as a seasoning, or even mix them into baked goods like cookies to give them a nutrient-enriched flavor,” Palinski-Wade added.

She advised keeping the following tips in mind when cooking with onion skins:

• Wash the onion (with skin on) thoroughly under running water and gently scrub off any dirt or residue. “Because onions grow underground, their skins can contain contaminants,” Pallinski-Wade said.
• Always use fresh, intact skins to avoid bitterness.
• Try roasting or lightly charring them before using them in foods to bring out a richer flavor and color.
• Avoid skins that appear moldy, blackened, or spoiled.

Keeping onion skins out of the trash and adding them to your recipes is worth it. Not only can you benefit from nutritional bonuses like increased antioxidants and fiber, but you’ll also help reduce unnecessary food waste.

Since it’s not recommended to eat onion skins raw, try incorporating them into soups or powdering them to add to other recipes.