careful with those red grapes

[heblaj01]

Risk from resveratrol in the skin of red grapes grown in large scale commercial vineyards is likeky to be very low if not nil.
This is because the level of resveratrol in these grapes is quite low.
Resveratrol is secreted in the skins as a reaction against fungus infestation.
Fungus is mostly found in cool climates & where antifungus sprays are not used.
In the US most grapes come from warm California big vineyards which are not shy of using protective sprays.
Ironically risk may be with small scale organically grown grapes (& even this is not a sure thing) in cool regions such as Washington or Oregon States or some places in Canada.
Concentrated resveratrol in pills is an other matter (to consider by those who are ER+)