The Health Benefits of Grapes

April 1, 2008


Brief History of Grapes

Grapes have been around since prehistoric times, and they have been cultivated since 5000BCE. The ancient Greeks and Romans valued the grape for making wine, and the grape features often in Greek mythology.

The ancient Egyptians considered wine a gift from Osiris, the god of resurrection, and its use was limited to the aristocracy. Perhaps the most famous literary mention is in The Fox and the Grapes, the fable by Aesop. After repeatedly attempting to grasp a bunch of ripe grapes hanging from a vine, the fox walked away with his nose in the air saying: “I am sure they are sour.” The moral of the story is: It is easy to despise what you cannot get.

The Spaniards introduced grapes into America 300 years ago, and they soon thrived in the Californian climate. Italy, France, Spain, the United States, Mexico, and Chile are among the largest commercial producers of grapes.

Nutrients in Grapes

Grapes are very good sources of manganese. They are good sources of vitamin B6, thiamine, riboflavin, potassium, and vitamin C. Resveratrol is classified as a polyphenol, a chemical substance found in plants that may have antioxidant properties. Several studies have demonstrated that resveratrol is an effective antioxidant, offering more protection than other antioxidants such as vitamins C and E. Resveratrol is isolated from the seeds and skins of grapes, and is primarily found in red wine, but also in lesser quantities in white wine and grape juice. Resveratrol content of wine is dependent on grape type and climate. Wines produced in humid climates have higher resveratrol content than those produced in hot and dry climates. Grape juice contains 10 times less resveratrol than wine, but also contains high levels of anthocyanadins, phenolic acids, and other polyphenols with antioxidant properties. Grape juice also contains piceid, a resveratrol derivative, and together with the other polyphenols, may have a beneficial health effect for those who cannot drink wine.

Grapes, purple or green Nutritional value per
100 g (3.5 oz)
Energy 288 kJ (69 kcal)
* Carbohydrates 18.1 g
Dietary fiber 0.9 g
* Fat 0.16 g
* Protein 0.72 g
Thiamine (Vit. B1) 0.069 mg
Riboflavin (Vit. B2) 0.07 mg
Niacin (Vit. B3) 0.188 mg
Pantothenic acid (B5) 0.05 mg
* Vitamin B6 0.086 mg
* Vitamin C 10.8 mg
Vitamin K 22 ?g
* Calcium 10 mg
* Iron 0.36 mg
* Magnesium 7 mg
Phosphorus 20 mg
Potassium 191 mg
A comprehensive breakdown of nutrients can be found in the Nutrition Database where this food can also be added to a meal planner.

Grapes for Cholesterol Reduction

Grape skin, pulp, and seed contain resveratrol, one of a group of plant chemicals credited with lowering cholesterol.

A study conducted in Spain involving 32 participants concluded that regular ingestion of concentrated red grape juice reduces plasma concentrations of oxidized LDL cholesterol.

In another study 61 healthy subjects with LDL cholesterol were administered grape seed extract tablets (proanthocyanidin). The results suggested that grape seed extract reduced oxidized LDL.

Several studies have concluded that regular ingestion of concentrated red grape juice reduces LDL cholesterol and may contribute to a reduction in cardiovascular disease risk.

Grapes for Alzheimer’s Disease

The 2006 Kame Project study published in The American Journal of Medicine concluded that fruit and vegetable juices consumption play an important role in delaying the onset of Alzheimer’s disease, particularly among those who are at high risk for the disease. In a follow up study the total phenolic content of 13 fruit juices were evaluated, and it was determined that purple grape juice contained the largest number of individual phenolic compounds and also the highest concentration of total phenolics.

Several observational studies have shown that moderate consumption of wine is associated with a lower incidence of Alzheimer’s disease.

Current drugs used in the treatment of Alzheimer’s disease may only slightly improve cognitive functions but have only very limited impact on the clinical course of the disease. In the past several years, based on in vitro and in vivo studies in laboratory animals, natural antioxidants, such as resveratrol have been proposed as alternative therapeutic agents for Alzheimer’s disease.

Positive effects in Alzheimer’s disease have been demonstrated with an oral preparation of glucose, malate and resveratrol, and a phase III trial is underway to validate the effectiveness of this combination in slowing the progression of Alzheimer’s disease.

Grapes for Cardiovascular Disease Prevention

Epidemiological data shows that the incidence of cardiovascular disease remains low in France, a phenomenon named the French Paradox and believed to result from the protective benefits of regular red wine consumption.

The specific components that are active on cardiovascular health are the polyphenols found in red wine, especially resveratrol. The effects of resveratrol on isolated tissues or organs include molecular mechanisms leading to decreased arterial damage, increased nitric oxide, decreased platelet aggregation and decreased activity of angiotensin (a protein that causes blood vessel constriction, leading to high blood pressure).

Results of a study involving 20 healthy participants indicated that flavonoids from the juice of purple grapes decrease platelet aggregation (blood clotting) and enhance nitric oxide release, a compound in the body that inhibits the formation of clots in blood vessels.

Grapes for Cancer Prevention

There is growing evidence that resveratrol can prevent or delay the onset of various cancers.

Recent studies indicate that resveratrol can block the process of cancer in the initiation, promotion and progression stages. Resveratrol appears to decrease tumor promotion activity by inhibiting cyclooxygenase-1 (COX-1), an enzyme that converts arachidonic acid to pro-inflammatory substances that stimulate tumor-cell growth.


Glycemic Index of Grapes

In a study to determine the glycemic index of various foods, it was concluded that grapes have a low GI of 40 – 50.

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