Grape therapy

Grape therapy, also known as ampelotherapy, is a form of naturopathic alternative medicine that involves heavy consumption of grapes, including seeds, and parts of the vine, including leaves. The concept has no scientific basis and is widely regarded as quackery.
Background.
An assumption of grape therapy is that consuming grape constituents would provide unusual therapeutic or nutritional benefits. However, consuming grapes has unknown effects against cardiovascular diseases and other diseases, such as metabolic syndrome. Alternative medicine practitioners have recommended grapes and parts of the vine for treating various diseases, but there is no clinical evidence for any such effects.
Grape pomace contains various micronutrients potentially having health properties, such as B group vitamins, vitamin C, calcium, magnesium, phosphorus, and potassium, as well as trace elements such as copper, iron, manganese, and zinc, but the resulting flour from pomace has variable nutrient contents due to processing, drying and storage conditions. Raw grapes are mostly devoid of nutritional benefit, except for moderate amounts of carbohydrates and vitamin K (see grape nutrition). 
Proanthocyanidins, anthocyanins and resveratrol extracted from grape seeds and grape skins are under basic research for their possible biological effects. Pomace also contains organic acids (tartaric, malic, citric, tannic), but there is no evidence for health effects from these phytochemicals.
History.
The documentation of grape cures was first seen in a publication by V.N. Dmitriev called “Treatment With Grapes in Yalta on the Southern Crimean Shore” (1878). In the USSR, the principles of the grape cure were developed in the 1920s by a group of physicians of the Semashko Institute (Yalta), headed by A.V. D'iakov. Ampelotherapy continues to be offered in alternative medicine clinics and spas, particularly in Europe, together with vinotherapy, a cosmetic treatment that involves rubbing grapes into the skin. 
Johanna Brandt, a South African author, popularized the grape diet as a treatment for cancer from 1925. She published about twenty pamphlets on the subject of natural remedies for health problems with her best-known publication being "The Grape Cure", which is said to have been written after Brandt had cured herself of stomach cancer by following the diet. The book was republished in 1989 as "How to Conquer Cancer, Naturally", including an endorsement of Brandt's work by Benedict Lust, who is commonly referred to as "the father of naturopathy". The book may have been inspired by Arnold Ehret, a contemporary, who taught a Grape Cure course.
Starting in the late 1980s, resveratrol in red wine was suggested as an explanation for the disputed "French paradox," the apparent low occurrence of heart disease among French people who drink red wine and consume a high-fat diet. Although commonly used as a dietary supplement and studied in human trials at amount much higher than can be consumed from drinking red wine, there is no high-quality evidence that resveratrol provides any benefits for cardiovascular risk factors.
Advocates of grape therapy argue that grape phytochemicals inhibit the development of cancer, arthritis or diabetes, but there is no scientific evidence for such effects. For example, a study carried out in Chianti in Tuscany, Italy, which assessed 783 people over age 65 who consumed a resveratrol-rich diet, found no link between the diet and rates of heart disease, cancer, or mortality rate.
Treatments.
The diet proposed by Johanna Brandt recommended fasting for two or three days, consuming only cold water, followed by a diet of only grapes and water for one to two weeks, with seven meals a day. Fresh fruits, tomatoes, and sour milk or cottage cheese are then introduced to the diet followed by raw vegetables.
Criticisms.
Available scientific evidence does not support claims that a diet of grapes is alone effective for treating cancer or any other disease. The Brandt diet, in particular, has been described as “quackery” by Barrett who notes that the American Cancer Society reviewed "The Grape Cure" in 1965, 1971, 1974, and 2000 and found no evidence of benefit against human cancer or any other disease. Grape seed extract has been identified by the U.S. Food and Drug Administration as a "fake cancer 'cure'".