Doctors Reveal What Eating Onions Really Does to Your Body

Onions are one of the most widely used vegetables in the world.

 They are nutritious and medicinal, but like many foods, they can have

side effects if consumed incorrectly or in excess. 

Does Eating Onion Cause Any Harm?

For most people, onions are safe and healthy. However, they can cause problems in certain situations:

1. Digestive Issues

Eating too much onion—especially raw—may cause:

• Bloating

• Gas

• Stomach pain

• Heartburn or acid reflux

This happens because onions contain fructans, a type of carbohydrate that is hard for some people to digest.

2. Irritation of the Mouth and Throat

Raw onions can irritate:

• The mouth

• The throat

• The stomach lining

People with sensitive digestion or gastritis should limit raw onion intake.

3. Blood Thinning Effects

Onions contain natural compounds that may thin the blood slightly.

• This can be beneficial for heart health

• But excessive intake may increase bleeding risk for people taking blood-thinning medication

4. Allergic Reactions (Rare)

Some individuals may experience:

• Skin rashes

• Itching

• Swelling of lips or tongue

If this happens, onions should be avoided.

Should Onions Be Eaten Raw or Cooked?

Eating Raw Onions – Pros & Cons

Benefits:

• Higher levels of vitamin C

• Stronger antibacterial and antioxidant effects

• May help lower cholesterol and blood sugar

Drawbacks:

• Harder to digest

• More likely to cause stomach discomfort and bad breath

👉 Best for: Healthy adults with strong digestion
👉 Avoid raw onions if: You have acid reflux, IBS, or a sensitive stomach

Eating Cooked Onions – Pros & Cons

Benefits:

• Easier to digest

• Gentler on the stomach

• Still retains many antioxidants

Drawbacks:

• Slight loss of vitamin C due to heat

👉 Best for: Children, elderly people, and those with digestive issues

Is Onion Eye Irritation Dangerous?

Why Do Onions Make You Cry?

When onions are cut, they release a gas called syn-propanethial-S-oxide.
This gas reacts with moisture in your eyes and turns into a mild acid.

Is It Harmful to the Eyes?

✅ No — it is not dangerous

• The irritation is temporary

• It does NOT cause permanent eye damage

• Tears are the body’s natural defense mechanism

However, in rare cases:

• People with dry eyes or contact lenses may feel stronger irritation

• Rubbing the eyes can worsen discomfort

How to Protect Your Eyes

• Cut onions under running water

• Use a sharp knife (less gas released)

• Chill onions before cutting

• Wear kitchen goggles if needed

How Much Onion Is Safe to Eat?

• Raw onion: ¼–½ medium onion per day

• Cooked onion: 1 medium onion per day is generally safe

Moderation is key.

Final Medical Advice

Onions are highly beneficial but not harmless in excess.
They should be eaten according to your digestive tolerance.

✔ Safe
✔ Nutritious
✔ Eye irritation is harmless
⚠ Avoid overconsumption
⚠ Remove raw onion if stomach sensitivity exists