Grape Polyphenols and Metabolic Syndrome

Fruits and vegetables are beneficial for patients with metabolic syndrome, a condition characterized by the coexistence of various risk factors (obesity, hypertension, hypercholesterolemia, insulin resistance) that predispose to cardiovascular disease and diabetes. Diets such as the Mediterranean diet, rich in flavonoids and polyphenolic compounds can exert a high anti-inflammatory, antithrombotic and antiproliferative action. Several studies have shown that grape polyphenols exert a crucial protective action against the onset of cardiovascular, neurodegenerative, and cancer diseases. On the other hand, little information is available on the health effects deriving from the consumption of table grapes on cell membranes lipidomic profile. On this basis, the aim of this study is the evaluation of possible changes in lipidomic profile and plasma antioxidant activity induced by a diet enriched with table grape polyphenols.

Purified polyphenols extracted by table grape can decrease cell proliferation in vitro and exert anti-atherosclerotic and antithrombotic activities, regulating endothelial function. Literature studies have already evaluated the cytostatic and apoptotic effects produced by table grape extracts from different cultivars, demonstrating a different behavior based on extract composition. The beneficial effects of polyphenols have been attributed exclusively to their direct antioxidant action; however, in recent years it has emerged that polyphenols can interact with intracellular signaling mechanisms, modulating the activity of transcription factors involved in cell lipid metabolism. Lipidomic analysis studies the lipids in a "dynamic" way, monitoring the changes in membrane phospholipids content, caused by inflammation, stress, or malnutrition. These changes can also affect the cellular and plasmatic prothrombotic potential, which results altered in metabolic diseases. Recently, alterations in erythrocytes lipidomic profile have been detected in subjects with steatosis. Moreover, in patients with colorectal cancer patients, the presence of metastases at the time of surgery was associated with an altered profile of fatty acids in the membrane of colonic tissue cells.

Moreover, data in literature show how diet and functional foods can modify serum lipid content, in particular, an important role in the onset of dysmetabolic diseases is undoubtedly played by the different fractions of Low-Density Lipoproteins (LDL). The presence of smaller LDL fractions in the serum, such as fraction 3 and fraction 4, has been associated with the onset of cardiovascular disease and myocardial infarctions. Therefore, understanding the molecular mechanisms underlying the effects of nutraceuticals is essential to develop prevention and intervention strategies on subjects at risk for metabolic syndrome.

On this basis, the aim of this study is the evaluation of possible changes happening in lipidomic profile, plasma antioxidant activity and plasma prothrombotic potential induced by a diet enriched with table grape polyphenols in subjects with metabolic syndrome.

Eligibility Criteria:
Inclusion Criteria:

* age \> 30 years and \<65 years
* overweight.

Exclusion Criteria:

* cardiovascular disease.
* stroke
* treatment with insulin or oral hypoglycemic drugs
* fasting glucose \> 126 mg / dl, or casual glycemia \> 200 mg / dl
* more than 20 g/day of alcohol intake
* serious medical conditions that may compromise participation in the trial
* subjects following a special diet or involved in a weight-loss program or unable to follow a diet for religious or other reasons.