Wine Information Council

Wine Information Council

There seems to be an increasing scientific interest in wine polyphenols and their influence on the gut microbiota.

The authors of this publication look at the current evidence regarding the relationship between red wine polyphenols and their influence on the gut microbiota.

Various red wine polyphenols including flavonoids (i.e. anthocyanins), non-flavonoids (stilbenes), catechins, etc. are supposed to exhibit positive health effects by reducing the oxidative stress in the body and promoting beneficial gut bacteria. Once digested, relatively small amounts of the wine polyphenols are absorbed by the small intestine (5-10%). These reach the colon as the central place of activity and metabolism by the gut microbiota.  

However, the differences between individuals play an important role in the bioavailability (the proportion of the polyphenols that enter the circulation and have an effect in the body) of polyphenols and their respective metabolites in the gut microbiota. The gut microbiota is relatively consistent through the adult life; however, it can be affected by changes in the diet and by antibiotic medication. It plays a critical role for the onset and development of several metabolic and inflammatory conditions/diseases.

The authors state there is no doubt that changes of the gut microbiota and the possible beneficial health outcomes depend on dietary intake; and understanding the benefits of red wine polyphenols on gut microbiota remains challenging and controversial. Some of these factors include the diversity of wines consumed and the variation in their polyphenolic content which is influenced by a variety of factors. Even with excessive doses, evidence of cardio-metabolic effects/benefits are inconclusive. Therefore, it is still unknown whether moderate to high intake levels will have beneficial health effects without negative implications on the gut barrier integrity and the gut microbiota.

The researchers conclude that the influence of red wine polyphenols on gut microbiota is becoming widely recognised, however, further research of low to moderate intake of those wine polyphenols over extended periods of time is necessary to elucidate the impact of various factors. They caution that wine consumption should always be studied in the context of overall dietary habits to account for residual confounding and bias. Results from large clinical studies are needed to establish a cause and effect relationship between red wine polyphenols and the gut microbiota.


Naumovski, N. et al, Untangling the two-way relationship between red wine polyphenols and gut microbiota, Gastroenterology (2019),

For more information about this article, read the scientific abstract here.

This prospective Danish study examined the influence of wine consumption during adolescence on the weight gain until midlife.

The results show that among non-smoking adolescents (average age at baseline 17 years), alcohol and particular wine consumption seems to be related to less weight gain until midlife during the 20 year follow-up period. The researchers conclude that whether this may be related to a specific lifestyle, including a health diet and habits associated with wine and drinking of alcoholic beverages during adolescense, or which functional properties in wine cannot be concluded from the present study.


Poudel P, Ismailova K, Andersen LB, Larsen SC, Heitmann, Adolescent wine consumption is inversely associated with lon-term weight gain: result from follow-up of 20-22 years, Nutrition J, 2019, 


Note from the Wine Information Council: consumption of wine and alcoholic beverages should be avoided by adolescents; authorities have established minimum ages for legally purchasing and drinking alcoholic beverages.


The researchers examined the individual and synergistic effects of the modifiable lifestyle factors of smoking and drinking on overall and site-specific cancer risk…..

Data from 26,607 adults, 35-69 years old participating in the Alberta’s Tomorrow Project were analysed. Associations between the consumption of alcoholic beverages, cigarette smoking, and cancer risk were examined. A total of 2,370 participants developed cancer during the study follow-up period.

The results showed that alcohol consumption was associated with colon cancer risk among men, showing evidence of a dose-response relationship. Wine was the only type of beverage with a significant impact on all cancer-risk: female wine drinkers had a 24% reduced risk for all cancers. As a possible mechanism, the authors suggest that the presence of flavonoids and resveratrol in red wine, which are believed to reduce cancer risk by inhibiting certain metabolic processes, may be involved.

Cigarette smoking appeared to have a greater impact on cancer risk compared to alcohol, affecting multiple cancer sites and overall cancer risk. The authors conclude that alcohol consumption was not statistically associated with cancer risk, however, cigarette smoking clearly increased all-cancer risk and females were more affected than men. Combined use of alcohol and smoking increased the risk of developing all, colon, and prostate cancers. A “U-shaped” interaction was observed for breast cancer when alcohol and tobacco were used in combination.


Viner B, Barberio AM, Haig TR, Friedenreich CM, Brenner DR, The individual and combined effects of alcohol consumption and cigarette smoking on site-specific cancer risk in a prospective cohort of 26,607 adults: results from Alberta’s Tomorrow Project, Cancer Causes Control. 2019 Sep 18. s10552-019-01226-7.

Two recent publications have reviewed the scientific evidence concerning the effects/impact of moderate wine consumption on human health.

One paper(1) gathered strong scientific arguments in favor of a low and moderate wine consumption as part of a healthy diet and lifestyle with special consideration of the wine-derived polyphenols.

The other review(2) summarised the accumulated evidence correlating moderate red wine consumption with prevention of coronary heart disease (CHD) and focused on the different mechanisms underlying this relationship……

There seems to be an ever-increasing tendency to underline the detrimental effects of alcoholic beverages on human health ,despite the multiple beneficial health effects demonstrated by research and despite the recorded steady decrease in wine consumption.

The current review considers the potential detrimental effects of alcohol, where demonstrated by science, however, the potential beneficial effects are also discussed, with a particular focus on the polyphenolic wine components.


Some of the research findings include:

Cardiovascular Diseases:

The benefits of a moderate intake of alcoholic beverages in reducing the risk of cardiovascular disease (CVD), and dying from this disease, have been demonstrated in numerous studies over the past three decades. Compared with abstainers, moderate drinkers have a decreased risk of CVD in all age groups, for both men and women but the most beneficial effects can be noted for middle-aged and older individuals when risk factors for CVD rise.


The relation between the consumption of alcoholic beverages and cancer is less clear cut.

What is a possible mechanism? An individuals’s response to alcohol will depend on his or her genetic profile. By exposure to predisposing factors (internal or external), the genetic material can be damaged. In normal, young persons, efficient mechanisms are in place to repair some of the damage. However, with age and in case of specificgenetic deficiencies, damaged DNA tends to accumulate in the cells, increasing the risk of cancers. From alcoholic beverages, the main agressor is not alcohol itself but one of its metabolites, the acetaldehyde, a known and recognized carcinogen. When the ethanol quantity is higher than the capacity of the liver to completely metabolize it, acetaldehyde accumulates in the cells and damages the DNA.

In wine, the presence of phenolic compounds may block or counteract the carcinogenic effect of acetaldehyde and alcohol.

The authors further describe in detail the well documented anti-oxidative, anti-blood-clotting, anti-proliferative effects as well as the immunomodulating actions of the polyphenols in wine. They suggest that many beneficial effects correlated with flavonoid intake from wine, grape and other sources may also be a marker of overall healthy dietary habits.

Their review of the research results, highlights however, the complexity of the relationship between wine and human health. They comment on the continuous challenge to integrate the results and the effcient interpretation of large amounts of data, in a way that can be useful at an individual or personal level.

Overall, wine consumers should be advised that to avoid the harmful physiological effects of rapid accumulation of alcohol and acetaldehyde in the body, it is important to consume alcoholic beverages with food and to stay hydrated to dilute these compounds.


Antoce AO, Stockley, C, An overview of the implications of wine on human health, with special consideration oft he wine-derived phenolic compounds, AgroLife Scientific J, Vol 8, No 1, 2019 


The second review(2) describes the scientific evidence of benefits related to the consumption of red wine which has been related to a lower risk of coronary heart disease (CHD)…..


Experimental studies and meta-analyses have mainly attributed this outcome to the presence of a great variety of polyphenolic compounds such as resveratrol, catechin, epicatechin, quercetin, and anthocyanin in red wine. These have anti-oxidant and anti-inflammatory properties contributing to reduce insulin resistance, changing plasma lipids and to decreasing oxidative stress of „bad“ LDL cholesterol (low-density lipoprotein cholesterol).

The authors conclude: As a consequence, a clear effect on the reduction of risk factors and the prevention of cardiovascular diseases have been observed. In light of these considerations, a moderate intake of red wine may produce cardioprotective effects. However, more in-depth knowledge is required in order to understand the molecular basis of the potential mechanisms involved.

  • Castaldo L , Narváez A , Graziani G, Gaspari A, Di Minno G, Ritieni A. Red Wine Consumption and Cardiovascular Health Molecules 2019, 24(19), 3626

doi. org/10.3390/molecules24193626

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