• Energy Research

ScopeThis study was designed to evaluate the influence of ethanol on the bioavailability of blackberry anthocyanins.Methods and resultsA total of 18 participants were recruited to consume 250 mL of a blackberry puree (650 mg of anthocyanins) without (BBP) or with 12% ethanol (BBP 12%). Venous blood was collected from participants at baseline and at 15, 30, 60, and 120 min after puree ingestion. Urine samples were collected at baseline and at 120 min. Plasma and urine concentration of anthocyanins and anthocyanin conjugates were quantified by HPLC‐DAD. Methyl‐cyanidin‐glucuronide (Me‐Cy‐Glucr) and 3′‐methyl‐cyanidin‐3‐glucoside (3′‐Me‐Cy3glc) were the main anthocyanin conjugates detected in all plasma and urine samples. Urinary concentration of these anthocyanin conjugates were positively correlated with their plasma concentration. Ethanol increased plasma Cmax of Me‐Cy‐Glucr and 3′‐Me‐Cy3glc. Participants were then stratified according to their body mass index (BMI) and body fat mass. After BBP consumption, plasma Cmax of Me‐Cy‐Glucr and 3′‐Me‐Cy3glc tended to be decreased in overweight/obese participants, in comparison to normal weight participants. The increase on plasma Cmax of Me‐Cy‐Glucr and 3′‐Me‐Cy3glc induced by ethanol was more pronounced in the group of overweight/obese participants.ConclusionsEthanol seems to enhance Cy3glc metabolism that appears to be compromised in overweight and obese individuals.

Wine, and particularly red wine, is a beverage with a great chemical complexity that is in continuous evolution. Chemically, wine is a hydroalcoholic solution (~78% water) that comprises a wide variety of chemical components, including aldehydes, esters, ketones, lipids, minerals, organic acids, phenolics, soluble proteins, sugars and vitamins. Flavonoids constitute a major group of polyphenolic compounds which are directly associated with the organoleptic and health-promoting properties of red wine. However, due to the insufficient epidemiological and in vivo evidences on this subject, the presence of a high number of variables such as human age, metabolism, the presence of alcohol, the complex wine chemistry, and the wide array of in vivo biological effects of these compounds suggest that only cautious conclusions may be drawn from studies focusing on the direct effect of wine and any specific health issue. Nevertheless, there are several reports on the health protective properties of wine phenolics for several diseases such as cardiovascular diseases, some cancers, obesity, neurodegenerative diseases, diabetes, allergies and osteoporosis. The different interactions that wine flavonoids may have with key biological targets are crucial for some of these health-promoting effects. The interaction between some wine flavonoids and some specific enzymes are one example. The way wine flavonoids may be absorbed and metabolized could interfere with their bioavailability and therefore in their health-promoting effect. Hence, some reports have focused on flavonoids absorption, metabolism, microbiota effect and overall on flavonoids bioavailability. This review summarizes some of these major issues which are directly related to the potential health-promoting effects of wine flavonoids. Reports related to flavonoids and health highlight some relevant scientific information. However, there is still a gap between the knowledge of wine flavonoids bioavailability and their health-promoting effects. More in vivo results as well as studies focused on flavonoid metabolites are still required. Moreover, it is also necessary to better understand how biological interactions (with microbiota and cells, enzymes or general biological systems) could interfere with flavonoid bioavailability.