Red Wine

What it is

Red wine is fermented grape juice that, besides alcohol (ethanol), contains plant compounds called polyphenols, such as resveratrol and anthocyanins, which have been studied for possible health effects [1]. The International Agency for Research on Cancer classifies ethanol as a Group 1 carcinogen [2].

How it might work

Wine polyphenols are proposed to act on blood vessels, inflammation and gut bacteria [1] [3] [4]. Effects of these compounds seen in animals are much more consistent than those seen in people [1] [5].

What the research says

Heart disease. A 2023 meta-analysis of 22 long-term observational studies found wine drinkers had a 24% lower risk of coronary heart disease and 27% lower risk of dying from cardiovascular disease than non-drinkers [6]. Observational studies cannot rule out that wine drinkers are healthier for other reasons [7]. Mendelian randomisation studies, which use genes that make people drink less as a natural experiment, point the other way: in 261,991 people, carriers of such a gene drank 17% less and had 10% lower odds of coronary heart disease [8]. A 2024 analysis concluded that observational data show a protective association while pooled genetic data show none [7].

Overall mortality. The largest analysis so far — 107 cohort studies with 4.8 million participants — found no lower risk of death among occasional or low-volume drinkers once study biases were accounted for, and a higher risk from 45 g of alcohol a day upwards; women drinkers had higher risk than women who never drank [9].

Cancer. Across 139 cohort studies, even light drinking was linked to higher risk of oesophageal, colorectal and breast cancer [10]. Genetic studies support a causal role of alcohol in cancers of the mouth and throat, oesophagus, bowel and liver [11]. Wine showed no clear link with lung cancer either way [2].

Cholesterol and blood sugar. In the two-year CASCADE trial, 224 adults with type 2 diabetes drank 150 ml of red wine, white wine or water with dinner; red wine raised HDL cholesterol by 0.05 mmol/L, while benefits for blood sugar appeared only in people who metabolise alcohol slowly [12]. A 2025 meta-analysis of wine trials found no pooled effect on HDL, total cholesterol or triglycerides, and a drop in LDL only in uncontrolled before-and-after studies [13]. In people with type 2 diabetes, 15 small studies did not support alcoholic drinks as a way to improve blood sugar [14].

Blood pressure, inflammation and gut. Red wine polyphenol extracts and resveratrol lowered systolic blood pressure by about 2.6 mmHg in human trials, though these were supplements, not wine [1]. But in 104,467 adults in Copenhagen, blood pressure rose with every weekly drink — about 0.15–0.17 mmHg higher systolic pressure per drink per week — and the effect was the same for red wine, white wine, beer and spirits [15]. Genetic studies suggest alcohol itself causes high blood pressure [11]. Red wine lowered some inflammation markers in healthy people but not in people with heart disease [3]. Dealcoholised red wine increased gut microbiome diversity and blood antioxidant capacity in short trials [4].

Brain. Genetic studies found no evidence that light drinking protects against cognitive decline or Alzheimer's disease [11], and trials of resveratrol, grape or wine found no significant effect on thinking skills, mood or brain volume [5].

Doses used in studies

The longest trial gave 150 ml of red wine with dinner for two years [12]. In the mortality analysis, 'low-volume' drinking meant 1.3–24 g of alcohol a day [9].

Safety and interactions

• Cancer: risk rises with the amount drunk, starting at light drinking, and the authors conclude there is no safe level of drinking for cancer risk [10].
• Higher intake: 45 g or more of alcohol a day is linked to higher overall mortality, and risk starts at lower amounts for women [9].
• Pregnancy: alcohol in pregnancy causes fetal alcohol spectrum disorder, which affects about 7.7 in 1,000 children worldwide [16]; higher exposure is linked to smaller head size and developmental problems [17].
• Medicines: many antibiotic warnings about alcohol rest on weak evidence, but some drugs (for example certain cephalosporins, ketoconazole and griseofulvin) can cause a disulfiram-like reaction, and erythromycin may work less well [18].
• Blood sugar: in people with diabetes on insulin or similar drugs, whether evening drinking causes low blood sugar overnight is unresolved [14].

Caveats and open questions

Most evidence on heart disease and mortality is observational and can be biased when former drinkers are counted as non-drinkers [9]. Trials are short and measure blood markers rather than heart attacks or deaths [13] [4]. Genetic studies struggle to separate light from moderate drinking [11].