Sweet Cherry.

Anthocyanins that have quenched a radical are left as a radical themselves, and ascorbate reduces them back to the active form in aqueous compartments. The two also co-occur in the fruit, so a whole cherry delivers the pair. This is well-described redox chemistry from solution studies. It does not establish that either changes a clinical outcome.

The tocopherol, ascorbate and polyphenol network is the standard textbook description of how cells cover both membrane and cytosolic compartments. Cherry polyphenols feed the aqueous side of that network. The interlocking chemistry is settled. Whether adding cherry to a diet already adequate in these vitamins changes anything measurable is a separate question.

Only a small percentage of ingested anthocyanin is absorbed as the parent glycoside, so most arrives in the colon and is metabolised by gut bacteria into protocatechuic acid and related phenolics. Those metabolites, not the intact pigment, carry much of what is measured in blood afterwards. That makes the microbial community a genuine gate on what the fruit delivers. The direction of the microbiota shift itself is early work measuring composition rather than an outcome.

Flavonoids compete for the same intestinal glucuronidation and sulfation capacity and for the same efflux transporters, so a large simultaneous dose of one can slow the conjugation of another. That competition can raise or lower circulating parent compound depending on which step is saturated. The interaction is real but its net direction depends on dose. Nobody should assume stacking flavonoids gives additive blood levels.

Melatonin is present in cherry fruit at nanogram-per-gram levels, which is orders of magnitude below a typical melatonin supplement dose. Anyone taking both is getting almost all of it from the supplement. The claim that cherry melatonin content explains sleep-related findings is not well supported by the quantities involved. The honest read is that cherry contributes a trivial share of total melatonin intake.

Whole-fruit studies deliver potassium, polyphenol, fibre and fructose together, so attributing a blood pressure reading to the anthocyanin alone overstates what the design can show. Potassium's role in vascular tone is established independently. This is a confounding note as much as a synergy. It matters for anyone reading cherry blood pressure trials as polyphenol evidence.

Dietary nitrate raises nitric oxide availability through the nitrate to nitrite to nitric oxide route, while fruit polyphenols are proposed to reduce oxidative loss of nitric oxide once formed. The two mechanisms converge without duplicating each other. The review evidence covering these food sources together is heterogeneous and cherry appears only within a broader category. Do not read this as a tested stack.

Ascorbic acid keeps iron in the ferrous state and forms a soluble chelate that survives the shift to intestinal pH, which is the standard explanation for why vitamin C-rich fruit raises iron uptake from a plant-based meal. Cherry supplies both ascorbate and malic acid. The effect requires the fruit and the iron source to be in the same meal. The polyphenol fraction pushes mildly in the opposite direction, so the net is modest.