What Happens If You Eat Too Much Onion? [Good or Bad for You]

Onion is scientifically known as Allium cepa L. (Liliaceae).

It belongs to the Liliaceae family of plants which includes over 250 genera and 3,700 species.

Being one of the oldest plants in history, the first documented use of onions is said to be in Central Asia.

In addition, consuming raw onions can aggravate heartburn in people who are prone to gastric reflux and other gastrointestinal sensitivities.

Although rare, there are individuals intolerant to onions and report an allergic reaction after skin contact.

Onion intolerance symptoms include nausea, vomiting, itchy eyes, and rashes.

Whether in their fresh form or in a powder, onions are eaten worldwide as a healthy, nutritious vegetable.

Red, yellow, and white onions are cultivated in the United States.

Red – Red onions are spicy, aromatic, and can be eaten raw or pickled.

Primarily used in salads, sandwiches, and burgers, their color and texture make them perfect for grilling and roasting.

Yellow – With a mildly sweet to full-flavored taste, yellow onions are multipurpose and can be used in a vast range of recipes.

Usually lightly cooked, they turn a rich, dark brown which is what gives the perennial French Onion Soup its color.

White – These onions are crisp and have the signature onion flavor with little to no after-taste.

They turn golden when cooked, having a mellow flavor that is popular in Latin and Italian cuisines, stir-fries, and sandwiches.

Onions are a rich source of vital nutrients such as:

• Fiber – for easy bowel movement and enhanced digestive health
• Vitamin C – an essential antioxidant, vital for boosting the immune system and supporting overall health
• Vitamin B6 – maintaining a functioning immune system
• Folate – aids in healthy cell and tissue development of the body
• Potassium – vital for proper cellular function and to offset the effects of sodium
• Calcium – responsible for healthy teeth and bones
• Manganese – plays a role in nutrient metabolism and blood sugar regulation
• Inulin – one of the essential types of dietary fiber which functions as a prebiotic and maintains digestive health

What are the side effects of eating too much onions?

The fermentable fiber, called oligosaccharides, is poorly absorbed by the system and has to be digested by the healthy gut bacteria in the large intestine.

These gut bacteria, called probiotics, help balance the digestive and immune systems and protect the cells in our gut from invading bacteria.

The fermentation process often results in excessive flatulence, and in worse cases, abdominal cramps.

In addition, consuming raw onions has been known to cause heartburn, especially in people that have irritable bowel syndrome (IBS).

Eaten in recommended quantities, onions have numerous health benefits in addition to having antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory properties.

Onions are one of the most versatile vegetables and can be found in nearly every cuisine.

They can be used in a variety of dishes in raw, marinated, grilled, pickled, sautéed, caramelized forms.

Cooking time and the heat used to affect the flavor of onions.

A high heat stir-fry produces intense flavors quickly while cooking over low heat for a long time enhances the sweetness and reduces the strong taste.

Onion leaves can also be equally beneficial.

Fresh onion leaves are an excellent dietary source of quercetin, vitamin C, carotenoids, and chlorophylls.

While the health benefits of eating onions are vast, overconsumption can lead to gastrointestinal difficulties such as flatulence, bloat, and cramps.

When eaten in moderate quantities, onions have numerous health benefits such as:

Anti-inflammatory properties

Onions have protective effects against inflammatory diseases of various vital organs. 

Various studies have found that onion’s anti-inflammatory properties are beneficial to the brain, which is especially effective against Parkinson’s disease, memory impairment, cerebral injury, and eye damage.

Support Heart Health

Onions contain high levels of antioxidants that decrease triglycerides, helping to reduce cholesterol levels.

Their potent anti-inflammatory properties also help reduce high blood pressure and reduce the risk of blood clots.

In addition, onions have a high concentration of quercetin, a flavonoid compound that further reduces the risk of hypertension and heart disease.

A study of 70 overweight people with high blood pressure reported that a 162 mg dose of onion extract significantly reduced blood pressure compared to a control group giving a placebo.

Anti-diabetic effects

Onions have potent antioxidants that reduce the risk of diabetes by reducing oxidative stress, moderating high blood glucose, and improving insulin activity.

Certain compounds in onion mimic insulin, the hormone responsible for regulating blood sugar levels.

Promoting gut health

Onions promote the growth of beneficial intestinal microorganisms, causing a protective effect on the digestive system.

As a prebiotic, the fermentable fibers found in onions feed the healthy gut bacteria in the colon responsible for boosting the immune system and balancing the digestive system.

Promoting respiratory health

Onion is observed to be beneficial for the treatment of respiratory problems, such as coughs, asthma, and bronchitis.

Studies have shown that onions could reduce lung inflammation and prevent lung damage.

Promoting reproductive health

Onions are rich in cysteine sulfoxides, unique amino acids found in onions.

These compounds have been shown to boost testosterone, the hormone that plays a significant role in male sexual characteristics.

In addition, a sulfur-containing compound found in onions has been found to suppress tumor development and help reduce the risk of cancers.

In addition, high amounts of onions can interfere with the efficiency of certain drugs like blood thinners.

Onions may also cause some side effects for people with sensitive digestive systems.

Fermentable carbohydrates like the oligosaccharides found in onions are known as FODMAPs.

The FODMAP group consist of:

• Oligosaccharides
• Disaccharides
• Monosaccharides
• Polyols

These are short-chain carbohydrates that our bodies have trouble digesting, notorious for causing digestive issues like diarrhea, gas, bloat, reflux, and stomach pain.

Irritable Bowel Syndrome, or IBS, affects millions of people around the world.

A low FODMAP diet has been shown to benefit those with IBS but does more harm than good for those without.

All varieties of onions are considered high FODMAP and should be excluded from the diet of anyone with IBS.

In addition, onions are a crop with some agricultural risks.

Inappropriate usage of some pesticides in the onion crop may cause health risks from onion consumption.

While the levels of pesticides are negligible in small doses, large amounts of onions can cause higher contamination levels.

In addition, the accumulation of heavy metals such as cadmium, lead, chromium, and nickel may transfer to the crop and cause food safety worries.

Irrigation water can be a source of contamination for the crop.