Types of Grapes May Be Triggers

Abstract

Intolerance reactions are not only associated generally with white, red, and rose wines but also with individual grape varieties. A case in point is the effect of the Merlot grape, which has become fashionable among wine drinkers in recent years. In patients with latent or manifest hypertension, a notable increase in blood pressure was observed after drinking Merlot, and this was accompanied by tachyarrhythmias. The reactions usually occur at night or in the early morning and are accompanied by symptoms resembling those of myocardial infarction. What is particularly striking is that even minute doses can trigger such reactions, and this also applies to blended wines consisting of a combination of several grapes, which often contain only 10–20% of Merlot. It is therefore recommended that these associations should be explained to patients with latent or manifest hypertension.