"Wine quality begins in the vineyard and is realized in the cellar."
(L. Bavaresco)
Resveratrol is a natural substance belonging to the stilbene family: a phytoalexin, meaning a substance synthesized by plant leaves and berries to combat potential attacks from pathogenic fungi, but also capable of countering damage from other sources, such as ultraviolet rays.
photo by Davide Biagi
It is present in 12 families of the Plant Kingdom, including the Vitis Viniferawhich is the most important species for the production of wine grapes.
It is the best known of polyphenols, and it is present in the skin of grapes and in red wine, in blueberries, raspberries and mulberries, in the roots of polygonum cuspidatum (plant used in China for its laxative properties), in berries, peanuts and pine nuts.
The vines that produce resveratrol in greater quantities are Pinot Noir and Cabernet Sauvignon.
But the factors that influence the quantity are many, primarily the grape variety, but also the age of the vineyards and the yield per hectare, followed by climate, altitude, latitude, soil type, and cultivation techniques.
Resveratrol research started following the so-called 'French Paradox' (Ferrières, 2004).
The term refers to some epidemiological studies conducted in the 1970s that had observed in France a lower rate of cardiovascular mortality despite a high consumption of saturated fats. One of the hypotheses to explain the apparent "paradox" had attributed to the habitual consumption of red wine, and in particular to its content of polyphenols, a protective role against heart disease (actually, on the medical source, even before the detection of resveratrol, the researchers had long been interested in wine as a protective drink against cardiovascular diseases).
Since the 1970s, numerous studies have been conducted to explore the pharmacology of resveratrol and identify potential medical applications. Most research on resveratrol includes in vitro or in vivo studies.
Effects 'Attributed' to Resveratrol
As a result of extensive research, this polyphenol has primarily been credited with biological effects that reduce the risk of cardiovascular diseases. Additionally, it is believed to boost the immune system against pathogens (anti-inflammatory properties) and to provide antioxidant benefits that combat cellular aging (this latter effect is thought to occur in conjunction with anthocyanins, another compound found in wine).
Even more important, research also highlights the potential of resveratrol to target cancer cells, inhibiting their proliferation through the action of sirtuins, proteins essential for cellular function.
Activating sirtuins would generally enhance the metabolic function of cells and help counteract conditions such as diabetes and obesity, by mimicking the effects of caloric restriction.
As a beauty elixir, numerous studies have demonstrated resveratrol's strong protective effect against skin aging through various mechanisms, primarily by stimulating collagen production and protecting against ultraviolet rays.
The results are promising, although further studies are needed to better understand the mechanism of action, effectiveness, safety and tolerability in humans.
Still under discussion
Some researchers point out the weakness of resveratrol's low bioavailability, which is the body's ability to use it (it is eliminated very quickly, even when taken in large doses). Therefore, to achieve the recommended doses of resveratrol, one would need to consume very high amounts of red wine, well beyond the levels of 'conscious' consumption.
Conversely, this view is challenged by other research which position the action of resveratrol in wine within a broader context, suggesting that wine is a complex compound containing many bioactive substances interacting with each other, potentially resulting in cumulative positive effects over time.
It is important to emphasize that scientific literature clearly indicates that alcohol abuse is severely harmful to health.
And this has led many health organizations and institutions responsible for disease prevention and health protection to suggest measures to encourage a strict containment of alcohol consumption, up to the achievement of zero alcohol (World Health Organization, 2022).
That said, it appears to us that the subject is still under extensive scientific research (some of which we have outlined in the section Resources).
Wine is undoubtedly different from all other alcoholic beverages and should be considered in all its various aspects, including its social value."
Resveratrol and Winemaking
Another aspect of great interest to us as wine producers is the relationship between viticulture/winemaking and the resveratrol content in wine.
Cultivation techniques are among the factors that affect the amount of final resveratrol: the low production of grapes per hectare, to which we strictly adhere, favors the presence of stilbeni in wine (as research shows “Fattori viticoli e resveratrolo nell’uva e nel vino “ – Bavaresco Gatti Van Zeller De Macedo Basto).
As an important research claims "... the production of grapes and wines with a high content of resveratrol is based on quality-oriented viticulture (suitable terroirs and sustainable cultivation practices) and winemaking technologies that prevent the degradation of the compound” (Hrelia-Malaguti).
How to say: according to researchers, a wine with a high content of resveratrol - as such - must have been produced with the utmost attention to quality.
And that alone is a wonderful conclusion—or rather, beginning—to the story.
“Stretch the bottle towards the light; you will see that your dreams are always at the bottom"
Rob Hutchison
