Why is red wine considered healthier?
The main difference between red and white wine lies in how long the juice remains in contact with the grape skins. In red wine, fermentation occurs together with the skins and seeds, while in white wine the juice is separated early. It may sound like a technical detail — but it significantly changes the drink’s biological composition.
Grape skins are rich in compounds called polyphenols, substances the plant produces as natural protection against sunlight and pests. When we consume them, they play a similar protective role in the body. Polyphenols act as antioxidants — meaning they neutralize “free radicals,” unstable molecules that form constantly through breathing, stress and environmental pollution. These free radicals can damage cell membranes, proteins and DNA, and their accumulation is associated with accelerated aging, heart disease and cognitive decline. Antioxidants bind to free radicals and prevent them from reacting with body tissues, functioning as a biological defense mechanism against cellular wear and tear.
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A glass of red wine contains roughly six to seven times more polyphenols than white wine,\
(Photo: Shutterstock)
But the story doesn’t end there. A large portion of polyphenols is not directly absorbed; instead, it reaches the colon and interacts with gut bacteria. There, a collaboration takes place: the bacteria break down these compounds into smaller, more active molecules, and in return, the polyphenols encourage the growth of beneficial bacteria over inflammation-promoting ones.
The result is the production of anti-inflammatory substances that affect the entire body. Among other effects, they improve insulin sensitivity — insulin is a hormone secreted by the pancreas that allows sugar to move from the bloodstream into cells for energy. When the body becomes “insulin resistant,” blood sugar remains elevated, accelerating blood vessel aging and increasing the risk of diabetes and heart disease. The substances produced by gut bacteria after breaking down polyphenols help cells respond better to insulin, contributing to balanced blood sugar levels. At the same time, they protect blood vessel walls and reduce overall inflammatory burden.
In other words, wine does not act only through the bloodstream but also through the digestive system, and much of its health impact is linked to the relationship between polyphenols and the microbiome.
A glass of red wine contains roughly six to seven times more polyphenols than white wine, which is why this effect is more pronounced in red. This is one reason studies have found that moderate red wine drinkers tend to have greater gut bacterial diversity — a marker associated with healthy aging and a stable immune system.
And what about white wine — is it inferior?
Not necessarily.
Recent studies show that white wine contains a different group of nitrogen- and sulfur-based compounds capable of trapping harmful oxidative byproducts, particularly in lung tissue. In other words, its advantage is different, not lesser. However, statistically, white wine consumption has been linked slightly more often with certain cancers, so from a health perspective, the balance still tends to favor red wine.
The microbiome: Why science is revisiting wine
It is now clear that our health depends heavily on the bacteria living in our gut. Polyphenols are not only antioxidants — they also function as prebiotics. Simply put, they feed beneficial bacteria, which in turn produce anti-inflammatory substances that protect blood vessels, the brain and the heart. This is why a glass of red wine with a meal has a different physiological effect than consuming strong distilled alcohol.
It is important to emphasize: the potential health benefit observed in studies does not come from the alcohol itself. Ethanol has well-known negative effects when consumed in excess, and any potential contribution of wine is related to the plant compounds in grapes and their fermentation products. This is not a recommendation to start drinking or to increase alcohol intake, but rather a scientific explanation of the biological differences between wine types when consumed in moderation.
A glass before bed? Here’s the twist
Despite the relaxing sensation, wine is actually a “sleep thief.” Alcohol initially causes drowsiness and muscle relaxation, making it easier to fall asleep. But that same relaxation can impair nighttime breathing and increase snoring or worsen sleep apnea. After the body metabolizes the alcohol, the opposite effect occurs: the nervous system becomes more alert, heart rate rises and sleep becomes lighter and more fragmented.
One of the main disruptions occurs in REM (Rapid Eye Movement) sleep — the “dream stage” during which the brain is highly active, memories are processed, emotions are regulated, and the nervous system recalibrates. This stage is critical for cognitive recovery and feeling refreshed in the morning. Alcohol suppresses REM sleep in the first half of the night, followed by a “rebound” of frequent awakenings. The result is sleep that may seem long but is not restorative — you sleep the hours, but the brain does not complete its recovery processes.
Importantly, this disruption is caused by ethanol itself, not by grape compounds. So even when wine contains nutritionally beneficial components, alcohol’s impact on sleep cycles remains. For this reason, it is advisable to separate wine consumption from bedtime by several hours, allowing the body to metabolize the alcohol before entering deeper sleep stages.
The bottom line
Research suggests that wine’s potential health effects stem not from the alcohol but from the grape’s natural compounds and from moderate consumption as part of a balanced diet. As in many areas of health, balance matters more than avoidance: not every glass is beneficial — but the right glass at the right time can fit within a healthy lifestyle.
That said, there are populations for whom the recommendation is entirely different. People with medical conditions that alcohol may worsen should avoid drinking and consult a physician. Wine should not be consumed during pregnancy, by children or in combination with certain medications that may interact with alcohol.
The writer is a healthy lifestyle researcher and a doctor of gerontology