Grape benefits and contraindications of consumption
Benefits of grape are composed mainly of presence in it a powerful antioxidant resveratrol, vitamins and active pigments. In addition to health benefits, grapes can bring harm to health.
Composition of grape.
One hundred grams of grape contain: proteins - 0.6 g, fat - 0.6 g, carbohydrates – 15.4 g, calorie - 72 kcal, as well as a rich set of macro- and microelements: potassium - 225.0 mg, calcium - 30.0 mg, magnesium - 17.0 mg, sodium - 26.0 mg, phosphorus - 22.0 mg, chlorine – 1.0 mg, sulfur – 7.0 mg, iron - 0.6 mg, silicon – 12.0 mg, manganese – 0.1 mg, zinc - 0.1 mg, iodine – 8.0 mcg, copper – 80.0 mcg, chrome – 3.0 mcg, fluorine – 12.0 mcg, molybdenum – 3.0 mcg, boron – 365.0 mcg, vanadium – 10.0 mcg, rubidium – 100.0 mcg, nickel – 16.0 mcg, aluminum – 380.0 mcg and cobalt – 2.0 mcg.
The list of contained in grape vitamins: A, B1, B2, B5, B6, B9, C, E, H, PP.
Grape benefits for health.
1. Cancer. Grapes contain powerful antioxidants known as polyphenols, which may slow or prevent many types of cancer, including esophageal, lung, mouth, pharynx, endometrial, pancreatic, prostate and colon.
The resveratrol found in red wine famous for heart health is a type of polyphenol found in the skins of red grapes.
2. Heart Disease. The flavonoid quercetin is a natural anti-inflammatory that appears to reduce the risk of 
atherosclerosis and protect against the damage caused by low-density lipoprotein (LDL) cholesterol in animal studies. Quercetin may have the additional bonus of anti-cancer effects; however more studies are needed using human subjects before these results can be confirmed.
The high polyphenol content in grapes may also reduce the risk of cardiovascular disease by preventing platelet build-up and reducing blood pressure via anti-inflammatory mechanisms.
A fiber and potassium in grapes also support heart health. An increase in potassium intake along with a decrease in sodium intake is the most important dietary change that a person can make to reduce their risk of cardiovascular disease, according to Mark Houston, MD, MS, an associate clinical professor of medicine at Vanderbilt Medical School and director of the Hypertension Institute at St Thomas Hospital in Tennessee.
In one study, those who consumed 4069 mg of potassium per day had a 49% lower risk of death from ischemic heart disease compared with those who consumed less potassium (about 1000 mg per day).
High potassium intakes are also associated with a reduced risk of stroke, protection against loss of muscle mass, preservation of bone mineral density and reduction in the formation of kidney stones.5
3. High Blood Pressure. As noted above, potassium has many benefits for the body. It may be that a low potassium intake is just as big of a risk factor in developing high blood pressure as a high sodium intake. Because of their high potassium content, grapes are recommended to those with high blood pressure to help negate the effects of sodium in the body.
According to the National Health and Nutrition Examination Survey, fewer than 2% of US adults meet the daily 4700 mg recommendation for potassium.
Also of note, a high potassium intake is associated with a 20% decreased risk of dying from all causes.
4. Constipation. Eating foods that are high in water content like grapes, watermelon and cantaloupe can help to keep you hydrated and your bowel movements regular. Grapes also contain fiber, which is essential for minimizing constipation.
5. Allergies. Because of the anti-inflammatory effects of quercetin, consuming grapes may help to alleviate symptoms of allergies including runny nose, watery eyes and hives. There have been no human studies done to prove this theory.
Researchers have also found resveratrol to be beneficial for treating Alzheimer's disease, relieving hot flashes and mood swings associated with menopause and improving blood glucose control, however large studies using human subjects are still needed to confirm these findings.
Grape: harm and contraindications.
Grapes contain a great amount of sugar, which makes it impossible to consumption of those who are sick with diabetes. Not recommended in diet include grapes, and people struggling with symptoms of obesity, liver cirrhosis, hypertension. Due to the fact that grape berries contain a high percentage of tartaric and malic acids, grapes contraindicated in peptic ulcer, stomatitis and caries. Caution is necessary to approach a question of use of grapes during pregnancy.