An intact clove does almost nothing. The bulb keeps a sulfur compound and the enzyme that activates it walled off in separate compartments. Break the wall and within seconds they make allicin, the molecule behind raw garlic's sting and most of its medicine. Your body turns allicin's breakdown products into hydrogen sulfide, the same gas it uses to relax blood vessels ¹ — which is why one bulb moves so many different numbers.

Heat kills the enzyme before it can work. Drop a whole clove into hot oil and the enzyme dies before any allicin forms. Crush the clove and let it stand ten minutes and the reaction finishes first; the compounds it leaves behind survive the pan.

Blood pressure is the strong claim. Across more than twenty randomised trials, a daily dose near one or two cloves drops systolic by five to ten points over two to three months in adults who already run high ^{2 3}. If your pressure is normal, the same dose does almost nothing.

Cholesterol and cancer move too. Total cholesterol falls about 17 mg/dL in people who start high ⁴ — an adjunct, not a statin. And in a 22-year trial in a high-risk region of China, a daily garlic extract cut stomach-cancer deaths by a third ⁵, lining up with population data across three continents ⁶.

The whole habit is one board trick, then cook as normal.

Most of the wins are silent.

• Two months: if you run high, the cuff reads lower, and the talk about adding a pill becomes a talk about waiting a quarter.
• The first winter: the cold that usually flattens you for a week might flatten you for three days, or skip you ¹⁰.
• Years out: cholesterol bends a few points, and the stomach-cancer dice tilt quietly in your favour, year after year ⁵.