Tresserra-Rimbau A, Medina-Remón A, Lamuela-Raventós RM, et al.; on behalf of the PREDIMED Study Investigators. Moderate red wine consumption is associated with a lower prevalence of the metabolic syndrome in the PREDIMED population. Br J Nutr. April 2015;113(Suppl 2):S121-S130.
Hyperlipidemia, hyperglycemia, hypertension, low high-density lipoprotein cholesterol (HDL-c), and abdominal obesity characterize metabolic syndrome (MetS). The incidence of MetS has increased in recent decades. A decreased risk of both MetS and cardiovascular disease (CVD) has been associated with consumption of a Mediterranean diet, which contains abundant fruits and vegetables, grains, legumes, nuts, olive oil, and moderate wine consumption. Saturated fats are limited in a traditional Mediterranean diet. The Mediterranean diet is thought to confer a protective effect against CVD and MetS through the high levels of antioxidants and anti-inflammatory agents found within the foods consumed. Red wine (RW), produced through the fermentation of grapes (Vitis vinifera, Vitaceae), is high in polyphenolic compounds, which are potent antioxidants. Some studies have found that RW consumption may benefit carbohydrate metabolism and hypertension. The goal of the current study was to analyze the data collected in the cross-sectional study Prevención con Dieta Mediterránea (PREDIMED) for correlations between RW consumption and the components of MetS.
The PREDIMED study, which was conducted in Spain, investigated the effects of a Mediterranean diet on individuals between the ages of 55 and 80. Participants filled out questionnaires concerning daily food and nutrient intake, alcohol intake, medications, and illnesses. Participants also completed a Spanish version of the Minnesota Leisure Time Physical Activity Questionnaire. Body weight, height, and waist circumference were measured. Body mass index (BMI) and waist to height ratio were calculated from these measures. Fasting blood samples were collected and analyzed for glucose and lipid concentrations. Blood pressure was also measured. Participants were categorized into 3 groups by RW consumption level. One group consumed no alcohol. A low alcohol consumption group consumed 0.1-1 drink per day, and a moderate to high alcohol consumption group consumed > 1 drink per day. Participants were classified as having MetS if they had 3 or more of the following symptoms: elevated waist circumference of > 102 cm in men or > 88 cm in women, triglyceride (TG) concentrations > 150 mg/dl or treatment to lower TGs, HDL-c concentrations ≤ 40 mg/dl in men or ≤ 50 mg/dl in women, elevated blood pressure with a systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 85 mmHg or treatment for hypertension, and fasting glucose > 100 mg/dl or treatment to reduce fasting glucose concentration. Data were analyzed with one-way analysis of variance, chi-squared tests, Fisher exact tests, Mann-Whitney or Kruskal-Wallis non-parametric tests, and multivariate models.
After eliminating participants not at high risk for CVD, 5801 participants remained, of which 2433 were women and 3368 were men. Based on their RW intake, approximately half of the participants did not consume any (n=3037), 36% were in the low RW consumption group (n=2086), and 12% were in the moderate to high RW consumption group (n=678). The participants in the higher RW consumption group were more likely to be smokers and have a higher activity level than the participants that consumed no RW (P<0.001 for both). In addition, participants in the higher RW consumption group had significantly greater intake of carbohydrates, proteins, and lipids and a lower intake of fruits and vegetables than the participants that consumed no RW (P<0.001 for all except vegetable consumption, P=0.023). Of the participants, 3897 were categorized as having MetS. The participants in the higher RW consumption group tended to have a lower BMI and heart rate and higher blood pressure than participants that consumed no RW (P<0.001 for all). Participants with high RW consumption were less likely to have elevated waist circumference, TGs, blood pressure, fasting glucose, or to be taking medications to control blood lipids, blood glucose, or blood pressure (P<0.001 for all). Using non-RW-consuming participants as a reference, low and moderate RW consumers had a significantly lower incidence of MetS than non-consumers (P<0.001). The risk of MetS was more greatly reduced in women than in men with higher alcohol consumption.
Of the participants included in this analysis, approximately 67% had MetS. Moderate RW consumption was correlated in this group with a decrease in MetS prevalence, including 4 out of 5 of its components—excessive waist circumference, low HDL-c, high blood pressure, and elevated blood glucose. The largest effect was seen in participants younger than 70 years of age and in women. Other studies have found that RW consumption appears to confer a reduction in risk of both MetS and CVD. It is not known whether this effect is due primarily to the alcohol or phenolic compounds in RW. Evidence from other cross-sectional, observational, and clinical trials suggests that both alcohol and phenolics may have beneficial effects on MetS symptoms. This study has limited value for the general population because it was conducted exclusively with older individuals at risk for CVD. In addition, it is possible that another component of the participants' diet influenced the expression of MetS and that RW co-varied with this component.
—Cheryl McCutchan, PhD
