For most healthy adults, ordinary amounts of garlic used in cooking are generally well tolerated.
The situation can be different when someone consumes large quantities of raw garlic.
Raw garlic is particularly potent because crushing or chopping it activates enzymes that produce allicin and other sulfur-containing compounds. These substances contribute to garlic's characteristic smell and flavor—but they can also irritate the digestive tract.
Some people experience:
- Heartburn or acid reflux
- Stomach pain
- Bloating
- Nausea
- Diarrhea
- Indigestion
- Burning or irritation of the mouth and throat
People with sensitive stomachs may notice these effects even at relatively modest amounts.
There is another important issue: garlic can affect blood clotting. Garlic supplements and very high intakes may increase bleeding risk, particularly when combined with medications such as warfarin and certain antiplatelet drugs.
This becomes especially relevant before surgery or dental procedures.
However, it is important not to confuse these known potential effects with a claim that ordinary garlic consumption directly damages the kidneys. There is not strong evidence that normal dietary garlic intake causes kidney inflammation in healthy people.
If kidney problems appear, doctors should look for established causes rather than assuming that a single food is responsible.
The safest approach is moderation. Garlic can add flavor and nutritional value to meals without requiring people to consume large amounts of raw cloves every day.
Chapter 3: Kidney Inflammation Has Many Possible Causes
The kidneys perform several critical jobs. They filter waste products from the blood, regulate fluid and electrolyte levels, help control blood pressure, and contribute to red blood cell production.