Allium sulfur compounds
Sulfur compounds
Allicin, ajoene, S-allyl cysteine: what stings in cut garlic and makes you cry with onion.
Allicin does not exist in the whole clove: it forms on cutting, and heat kills the enzyme. Chop, wait ten minutes, then cook.
Effects and benefits
Cutting a garlic clove triggers a chain reaction that makes allicin, the plant's weapon. In meta-analyses of trials, garlic lowered blood pressure by about 8 points in people whose pressure was high, and total cholesterol by about 0.4 mmol/L.
In the intact clove, alliin and the enzyme alliinase are kept apart. Cut or crushed, they meet within seconds: allicin forms, with its smell and bite. In 1944, Chester Cavallito isolated it while looking for why garlic slowed bacteria (Cavallito and Bailey, 1944).
Meta-analyses of trials measured the effect on blood pressure: in people with hypertension, garlic, especially aged, lowered systolic pressure by about 8 points (Ried, 2016); it is not a reason to stop a treatment. Total cholesterol fell by about 0.4 mmol/L in people whose levels were high (Ried et al., 2013).
Aged garlic, kept for months, loses its allicin but gains S-allyl-cysteine, stable and well absorbed: it is what many trials used.
As a high-dose supplement, garlic can thin the blood slightly: mention it before surgery or with an anticoagulant.
Sources: Cavallito and Bailey, JACS, 1944 · Ried, J Nutr, 2016 · Ried et al., Nutr Rev, 2013
Where to find it (22)
- Anzur (Persian shallot)
- Chives
- Crow garlic
- Dallae
- Few-flowered garlic
- Garlic
- Garlic chives
- Garlic scapes
- Leek
- Nobiru
- Onion
- Rakkyo
- Ramps
- Sand leek
- Scallion
- Shacong (Mongolian onion)
- Shallot
- Three-cornered leek
- Victory onion
- Wakegi
- Wild garlic
- Wild garlics