Are Onions Good For You?

Onions are low in calories but packed with essential nutrients.

Onions are indeed good for you and offer several health benefits. Onions are members of the Allium genus of flowering plants that also include garlic, shallots, leeks, and chives. These vegetables contain various vitamins, minerals, and potent plant compounds that have been shown to promote health in many ways.

Onions are low in calories but packed with essential nutrients. They are a good source of vitamin C, vitamin B6, folate, potassium, and dietary fiber. They contain various antioxidants, including flavonoids and sulfur compounds like quercetin[1] and allicin[2]. These antioxidants help protect the body against oxidative stress, which can contribute to chronic diseases such as heart disease and certain cancers. Onions have been linked to improved heart health.

One medium onion has just 44 calories but delivers a considerable dose of vitamins, minerals, and fiber

They may help reduce blood pressure, lower cholesterol levels, and decrease the risk of heart disease due to their antioxidant and anti-inflammatory properties. The sulfur compounds found in onions, especially quercetin, have anti-inflammatory effects.

This vegetable is particularly high in vitamin C, a nutrient involved in regulating immune health, collagen production, tissue repair, and iron absorption. Vitamin C also acts as a powerful antioxidant in your body, protecting your cells against damage caused by unstable molecules called free radicals

They may help reduce inflammation in the body, which is associated with various chronic conditions like arthritis, asthma, and inflammatory bowel disease. Some studies suggest that onions may have cancer-fighting properties.

Onions are also rich in B vitamins, including folate and vitamin B6 — which play key roles in metabolism, red blood cell production, and nerve function

The antioxidants in onions can help neutralize free radicals, which may contribute to the development of cancer. Additionally, certain compounds in onions have shown the potential in inhibiting the growth of cancer cells, particularly in digestive tract cancers such as colorectal and stomach cancer.

Lastly, they’re a good source of potassium, a mineral that many people are lacking. In fact, the average potassium intake of Americans is less than half the recommended daily value (DV) of 4,700 milligrams (mg). Normal cellular function, fluid balance, nerve transmission, kidney function, and muscle contraction all require potassium.

Onions are rich in vitamin C, which plays a crucial role in supporting a healthy immune system. Vitamin C helps stimulate the production of white blood cells and antibodies, which are essential for fighting off infections. They contain a type of dietary fiber called inulin, which acts as a prebiotic.

Prebiotics promote the growth of beneficial gut bacteria, supporting a healthy gut microbiome and aiding digestion. Onions can fight potentially dangerous bacteria, such as Escherichia coli (E. coli), Pseudomonas aeruginosaStaphylococcus aureus (S. aureus), and Bacillus cereus[3]. Furthermore, onion extract has been shown to inhibit the growth of Vibrio cholerae[4]a bacteria that is a major public health concern in some parts of the world.

Eating onions may help control blood sugar, which is especially significant for people with diabetes or prediabetes. An older study in 42 people with type 2 diabetes demonstrated that eating 3.5 ounces (oz), or 100 grams, of raw red onion significantly reduced fasting blood sugar levels after 4 hours. Specific compounds found in onions, such as quercetin and sulfur compounds, also possess antidiabetic effects. For example, quercetin has been shown to interact with cells in the small intestine, pancreas, skeletal muscle, fat tissue, and liver to control whole-body blood sugar regulation

A study of 24 middle-aged and postmenopausal females showed that those who consumed 3.4 oz (100 milliliters) of onion juice daily for 8 weeks had improved bone mineral density and antioxidant activity compared to a control group. Another older study in 507 perimenopausal and postmenopausal females found that those who ate onions at least once a day had a 5% greater overall bone density than individuals who ate them once a month or less.

Plus, the study demonstrated that older individuals who most frequently ate onions decreased their risk of hip fracture by more than 20% compared to those who never ate them. It’s believed that onions help reduce oxidative stress, boost antioxidant levels, and decrease bone loss, which may prevent osteoporosis and boost bone density.

Sweet onions are less tearing and a perfect choice to consume raw. Sweet onions are also called Mauis, Vidalias, OsoSweets, Walla Wallas, and Texas sweets. The shape varies from round to flattened. The mildness of Sweet Onion is due to low sulfur content (especially pyruvic acid[5]) and the content of water when compared to other onion varieties. They have the same health benefits as other onions.

Onions give flavor to savory dishes and can be enjoyed either raw or cooked. Adding more onions to your diet is an easy way to benefit your overall health.

  • Use raw onions to add a kick of flavor to your guacamole recipe.
  • Add caramelized onions to savory baked goods.
  • Combine cooked onions with other vegetables for a healthy side dish.
  • Try adding cooked onions to egg dishes, such as omelets, frittatas, or quiches.
  • Top meat, chicken, or tofu with sautéed onions.
  • Add thinly sliced red onions to your favorite salad.
  • Make a fiber-rich salad with chickpeas, chopped onions, and red peppers.
  • Use onion and garlic as a base for stocks and soups.
  • Throw onions into stir-fry dishes.
  • Top tacos, fajitas, and other Mexican dishes with chopped raw onions.
  • Make a homemade salsa with onions, tomatoes, and fresh cilantro.
  • Prepare a hearty onion and vegetable soup.
  • Add onions to chili recipes for a flavor boost.
  • Blend raw onions with fresh herbs, vinegar, and olive oil for a tasty homemade salad dressing.

  1. Quercetin is a flavonoid, a type of plant pigment found in various fruits, vegetables, and grains. It is widely recognized for its potent antioxidant and anti-inflammatory properties. Quercetin is known to scavenge free radicals and protect cells from oxidative damage, thereby reducing the risk of chronic diseases. It also exhibits anti-inflammatory effects by inhibiting certain enzymes and signaling pathways involved in inflammation. Quercetin has been associated with various health benefits, including improved heart health, cancer prevention, immune system support, and potential anti-allergic and anti-viral effects. While quercetin is naturally present in foods, it is also available as a dietary supplement. However, more research is needed to fully understand the mechanisms and potential therapeutic applications of quercetin. [Back]
  2. Allicin is a bioactive compound found in garlic (Allium sativum) that is responsible for its distinctive odor and many of its health benefits. When garlic is crushed or chopped, an enzyme called alliinase converts alliin, a sulfur-containing amino acid, into allicin. Allicin is known for its antimicrobial, antioxidant, and potential anticancer properties. It exhibits antimicrobial effects against a wide range of bacteria, viruses, and fungi. Additionally, allicin has been shown to possess antioxidant activity, which helps protect cells from oxidative stress and damage. Some studies suggest that allicin may also have anticancer potential by inhibiting the growth of cancer cells and inducing apoptosis, or programmed cell death. However, more research is needed to fully understand the mechanisms and therapeutic applications of allicin. [Back]
  3. Escherichia coli (E. coli) is a type of bacteria commonly found in the intestines of humans and animals. While most strains of E. coli are harmless, some can cause gastrointestinal infections and urinary tract infections. Pseudomonas aeruginosa is a versatile and opportunistic bacterium that can cause infections in various parts of the body, particularly in individuals with compromised immune systems or chronic illnesses. It is known for its ability to develop resistance to antibiotics and can cause severe infections in hospital settings. Staphylococcus aureus (S. aureus) is a bacterium commonly found on the skin and in the nasal passages of healthy individuals. However, it can also cause a range of infections, including skin infections, pneumonia, and bloodstream infections. Methicillin-resistant Staphylococcus aureus (MRSA) is a strain of S. aureus that is resistant to many antibiotics. Bacillus cereus is a spore-forming bacterium that can be found in soil, dust, and some food products. It is associated with foodborne illnesses and can cause gastrointestinal symptoms such as vomiting and diarrhea. Understanding these bacteria and their associated infections is crucial for effective prevention, diagnosis, and treatment strategies. [Back]
  4. Vibrio cholerae is a bacterium responsible for causing cholera, a severe diarrheal disease. It is primarily transmitted through contaminated water and food sources. V. cholerae produces a toxin called cholera toxin, which leads to the characteristic symptoms of cholera, including profuse watery diarrhea and dehydration. The bacterium thrives in areas with poor sanitation and inadequate access to clean water. Cholera outbreaks can occur in densely populated areas, especially during emergencies or natural disasters. Prompt treatment with oral rehydration therapy and, in severe cases, intravenous fluids and antibiotics can help manage cholera. Prevention strategies focus on improving water and sanitation systems, promoting hygiene practices, and administering cholera vaccines in high-risk areas. [Back]
  5. Pyruvic acid is an important compound in biochemistry and metabolism. It is a three-carbon molecule that plays a central role in cellular respiration and energy production. During glycolysis, glucose is broken down, and pyruvic acid is generated as an intermediate product. Pyruvic acid can undergo further metabolic processes depending on the availability of oxygen. In the presence of oxygen, it enters the citric acid cycle (also known as the Krebs cycle) in mitochondria, where it is further oxidized, releasing energy in the form of ATP. In the absence of oxygen, pyruvic acid can undergo fermentation, converting into other molecules such as lactic acid or ethanol, depending on the organism and specific conditions. Additionally, pyruvic acid serves as a precursor for several important molecules in the body, including amino acids and fatty acids. Its versatile nature and involvement in various metabolic pathways make pyruvic acid a crucial molecule for energy generation and biosynthesis. [Back]

Further Reading


Author: Doyle

I was born in Atlanta, moved to Alpharetta at 4, lived there for 53 years and moved to Decatur in 2016. I've worked at such places as Richway, North Fulton Medical Center, Management Science America (Computer Tech/Project Manager) and Stacy's Compounding Pharmacy (Pharmacy Tech).

Leave a Reply

%d bloggers like this: