Resveratrol: The Polyphenol from the Grape

It sounds like a contradiction: in parts of France people eat richly, enjoy cheese and red wine – and yet cardiovascular problems were long considered comparatively rare there. The "French paradox" made headlines in the 1990s, and at its centre stood a molecule that keeps longevity research busy to this day: resveratrol.

Short and to the point: resveratrol is a polyphenol from the stilbene group, found above all in grape skins, red wine and Japanese knotweed. The relevant, well-studied form is trans-resveratrol. It is an antioxidant in the laboratory and a subject of ageing research – but health-related claims are not authorised for food supplements.

The most important points at a glance

• Resveratrol is a polyphenol (stilbene) from grape skin, red wine and knotweed.
• The active, well-studied form is trans-resveratrol.
• As a molecule it is an antioxidant in laboratory studies and a focus of longevity research.
• Its bioavailability is considered limited – an honest point.
• For resveratrol there are no authorised health claims in the EU – we describe it neutrally.

What is resveratrol – and what does it do in the plant?

Resveratrol belongs to the stilbenes, a subgroup of the polyphenols. Plants don't produce it for fun, but as an active defence substance: when a grapevine is under attack from fungi or stressed by UV radiation, it ramps up resveratrol production. This is precisely why the substance sits preferentially where the protection is needed most – in the skin of red grapes. The fruit juice inside contains hardly any.

For humans, resveratrol is present in the diet mainly in grape skins and red wine – in small amounts. For food supplements it is usually obtained from Japanese knotweed (Polygonum cuspidatum), a plant that is naturally particularly rich in it and can be processed into standardised extracts.

trans- or cis-resveratrol? Why the form matters

Resveratrol occurs in two spatial variants: trans and cis. You can picture them as two folds of the same molecule. Almost exclusively the more stable trans-resveratrol is studied and offered – it is the form that counts in studies and products. When buying, therefore, look for a stated trans-resveratrol content. Because the substance is UV-sensitive (it partly "flips" from trans to cis under the influence of light), it belongs in light-protected packaging and dark storage.

The "French paradox" and what research is investigating

Resveratrol became known through the French paradox mentioned above. Later it moved into the focus of sirtuin and longevity research – sirtuins are enzymes that are associated with cell metabolism and ageing processes, and resveratrol was discussed as a possible activator. That is exactly what made it the star of many headlines.

Honestly put into context, that means: these are research topics, much of it from cell and animal models. Robust, authorised health-related claims for food supplements cannot be derived from them. That is not a flaw, but the serious way of handling a fascinating molecule: staying curious without promising more than is established.

Bioavailability – the honest sticking point

One point that reputable suppliers do not conceal: resveratrol is rapidly metabolised in the body, and its bioavailability is considered limited. That is why some products combine it with piperine (from black pepper) or rely on special formulations to support absorption. Because resveratrol is fat-soluble, it is advisable to take it with a fat-containing meal – you'll find the practical side of this in Resveratrol: Intake and Combination. The basics of absorption are explained in Bioavailability Simply Explained.

Resveratrol in the longevity context

Resveratrol is one of several plant compounds that many people find interesting in the context of "healthy ageing" – alongside substances such as spermidine or OPC. What you should realistically know about this is put into context by Longevity: What's Behind the Trend? The honest truth: the basis for an active life is formed by nutrition, exercise and recovery – not a single supplement.

Scientific classification

For resveratrol there are currently no authorised health-related claims in the EU. We therefore make no claims of efficacy, but describe origin, forms and use factually. Authorised cell-protection claims relate exclusively to nutrients such as vitamin C and vitamin E, which contribute to the protection of cells from oxidative stress. In the case of existing illnesses, medication use, pregnancy and breastfeeding the rule is: clarify with a doctor beforehand. This article provides general information and is no substitute for medical advice.

Matching products from Scheunengut

You'll find resveratrol capsules with trans-resveratrol in the Resveratrol category. We stock related antioxidants and polyphenols in the OPC and Quercetin categories; the Longevity category fits the topic of healthy ageing. Further guides on the subject: OPC, Quercetin, Astaxanthin and Spermidine.

Frequently asked questions (FAQ)

What is resveratrol for food supplements obtained from?

Usually from Japanese knotweed (Polygonum cuspidatum), which is naturally particularly rich in trans-resveratrol. Resveratrol could also be obtained from red grapes, but knotweed delivers higher and more consistent levels for standardised extracts.

What is the French paradox?

This is the name for the observation that in parts of France comparatively few cardiovascular problems occurred despite a rich diet. This was linked, among other things, to red wine and the resveratrol it contains. It is an observation from which no established claims of efficacy can be derived.

Is resveratrol an antioxidant?

As a molecule, resveratrol acts antioxidatively in laboratory studies, meaning it can scavenge free radicals. What a molecule does in a test tube, however, cannot be transferred one-to-one to the body. No health-related claims are authorised for food supplements.

Why is resveratrol light-sensitive?

The stable trans form can partly convert into the less stable cis form under UV light. So that the trans content is preserved, resveratrol belongs in light-protected packaging and should be stored cool and dark.

This article serves as general information and is no substitute for individual medical advice.