Effect of an Extract From the Wine Industry on Blood Pressure (HYPERGRAPES)

The main objective of the study is to evaluate the effect of daily intake of an extract from the wine industry on the change in systolic blood pressure values in individuals with high blood pressure and grade 1 hypertension. Secondary objectives are to evaluate the effects of an extract from the wine industry on: * The change in diastolic blood pressure values. * The change in body weight, body mass index (BMI) and waist circumference. * The change in the circulating values of total cholesterol, LDL-c, HDL-c, triglycerides and ApoB. * The change in the atherogenic index of plasma, which combines triglycerides and HDL-c values and which is considered a good indirect indicator of LDL-c particle size and subclinical atherosclerosis. * Glucose metabolism and insulin resistance. * The change in the inflammation values analyzed by the marker high sensitivity C-reactive protein. Study Design: Randomized, crossover, placebo-controlled and double-blind nutritional intervention trial. The number of subjects in the study will be 40. After the pre-screening visit, the participants will be randomly divided into two groups of 20 participants, according to start the study by taking the extract from the wine industry or placebo for 5 weeks. At the end of the week 5 of the study, when the first treatment is finished, there will be a washing period for 3 weeks and then the treatment will be changed for another 5 weeks: a total of 14 weeks. The containers of the two treatments, the extract from the wine industry and the placebo, will present the same shape and appearance. The two products will present similar organoleptic characteristics of taste and color. Each volunteer will make 5 visits, according to the crossover study design: * a pre-selection visit (to check inclusion / exclusion criteria) (V0; week1) and, in case of meeting the inclusion criteria, * two study visits during the consumption of the first product (extract from the wine industry or placebo), which will take place on the first day of study (V1; week 2) and after 5 weeks of treatment (V2; week 7). * two study visits during the consumption of the second product (extract from the wine industry or placebo), which will take place after the three week washout period (V3; week 10) and after 5 weeks of treatment (V4; week 15). In all visits except the V0 visit, participants must present themselves in fasting conditions of 8 hours to obtain blood. In addition, on V2 visits and V4 the participants will be asked the presence / absence of adverse effects that could be associated with the consumption of the study products. Main variable: Systolic blood pressure levels. Secondary variables: * Diastolic blood pressure levels. * Body weight. * Height. * Body mass index (BMI) (Kg/m2). * Waist circumference. * Conicity index. * Waist circumference/Height ratio. * Parameters in serum: * Glucose. * Insulin. * Homeostatic Model Assessment for insulin resistance index (HOMA-IR). * Total cholesterol. * High density lipoproteins cholesterol (HDL-c). * Low density lipoproteins cholesterol (LDL-c). * Triglycerides (TG). * Atherogenic indices: * Total cholesterol/HDL-c * LDL-c/HDL-c * Plasma atherogenic index, calculated as the logarithm of the TG/HDL-c ratio. * Apolipoprotein (apo) B. * C-reactive protein. * Faecal intestinal microbiota composition. * Physical activity record. * Record of potential adverse events. * Frequency of consumption of supplements to avoid in the study. * Completion of the intervention.