Grapes – characteristics and advantages, during pregnancy... grapes and weight loss

Common grapevine (Vitis vinifera L.. ), is a species of climbing plant from the grape family, found in a temperate climate zone and belonging to the group of oldest cultivated plants by humans. The berries of this plant are ovoid or round, contain 2 to 4 seeds and range in color from light green to black, depending on the variety. Fruit maturation occurs towards the end of summer. The ripe grapes are characterized by a sweet-sour taste. They can be consumed directly from the bush, used in the preparation of desserts, fruit oil, jam, wine, juices and other processed products.

A plethora of studies and research show the beneficial properties of grapes for human health. Special attention is given to the content of phenolic substances (bioflavonoids) and their functions. The total number of these compounds depends on the type of grape. The darker the grape variety, the more polyphenols it contains. In the seeds, catechins, epicatechins, and gallic acid are present, while in the skin: quercetin, kaempferol, myricetin, ellagic acid and resveratrol are found. The most important functions of bioflavonoids include: anti-inflammatory and antioxidant activity, protection against the formation of free radicals, antihistaminic action, reduction of allergic reactions, inhibition of virus reproduction, prevention of circulatory system disorders (coronary heart disease, atherosclerosis), certain types of cancer and diseases of old age. Interestingly, in the 1990s, the "French paradox" gained popularity. The number of people with cardiovascular diseases in France was very low, despite their diet being rich in saturated fats. It turned out that this was due to the protective effect of phenolic substances contained in red wine, which the French often drink with meals. Among the flavonoids contained in grapes, resveratrol deserves special attention. It is characterized by high biological activity, and the phenomenon of the "French paradox" has increased interest in this compound. Its amount in the fresh skin of grape fruits ranges from 50 to 100 μg of resveratrol/1 g of dry mass and depends on the variety - dark grapes contain the most of it. Resveratrol favorably affects lipid metabolism, inhibits platelet aggregation and lipoprotein oxidation, reduces the activity of peroxidative enzymes (cyclooxygenase, lipoxygenase) and contributes to the formation of complexes with metals catalyzing oxidation reactions. This compound positively affects the circulatory system and protects the body against neurodegenerative diseases. Importantly, there are studies suggesting a favorable effect of resveratrol on the pathophysiological mechanisms in Alzheimer's disease. It counteracts damage to neurons and reduces the amount of amyloid substance deposited in the brain. Resveratrol also inhibits the development of cancers by affecting the main stages of carcinogenesis. It modulates signaling pathways that control cell division and growth, the inflammatory process, apoptosis, angiogenesis and metastasis formation. Thanks to its anti-inflammatory, antioxidant, anti-mutagenic and anti-proliferative properties, it can find application in the prevention of carcinogenesis.

The flavonoids found in grapes impact the correct circulation of blood in the placenta, protect cells from damage caused by harmful substances, and boost the immune system. B vitamins and fiber aid in metabolism, and dietary fiber also prevents constipation. Grapes also contain iron (especially light varieties), which helps prevent anemia, and iodine, which is responsible for proper thyroid function and fluid development. Grapes have a medium glycemic index (IG = 45). They contain large amounts of easily digestible carbohydrates such as glucose and fructose, so pregnant women with gestational diabetes should limit their intake. Thanks to the higher content of antioxidants, dark grapes exhibit a stronger antibacterial effect than light ones and can help reduce the adherence and retention of bacteria in the walls of the bladder in the event of a urinary tract infection during pregnancy. However, it should be noted that consuming red grape juice may decrease iron absorption from food.

Resveratrol in grapes lessens the risk of overweight and obesity, among other things, by inhibiting the peroxidation of lipids and decreasing the absorption of oxidized LDL in the walls of blood vessels. Moreover, it influences the regulation of energy balance by activating the protein SIRT1 (an appetite-regulating enzyme), which likely facilitates the body's adaptation to decrease the amount of absorbed energy through the activation of PGC-1 (a glucose trigger in the liver).