The load-bearing fact is behavioural. Herbs make food taste finished at a lower sodium level, and that displacement is the strongest thing in the file: about a gram of salt a day off the plate, sustained at six months ¹.

The rest is smaller and real. Per gram, herbs top the polyphenol charts — well above berries, above any common vegetable ². A 5g sprig of parsley carries more vitamin K than most adults need in a day ³. Parsley and dill run high in nitrate, which your body turns into nitric oxide and a small vessel-widening effect ⁴. In one crossover meal, a herb-and-spice blend cut the post-meal triglyceride rise by roughly a third ⁵. Over years, high habitual polyphenol intake tracks with about half the cardiovascular event rate of low intake ⁶.

The dose that earns its space is a handful — about three tablespoons chopped, half a grocery bunch of parsley, thirty basil leaves. A single garnish leaf does nothing.

Taste shifts first, within a week. A roasted vegetable tastes finished with parsley folded through; a plain rice bowl gets interesting with cilantro. The hand stops reaching for the saltshaker.

Over a month or two the household eats more vegetables, because they stop being an obligation. The years-long part is invisible: sodium settles about a gram a day lower, polyphenol intake climbs into the range where heart-event rates run lower ⁶. This is a slow, compounding additive, not a one-month biomarker fix — and the effort and cost are small enough that the return still pencils out.