Necessary preface: no wine extends anyone's life, and alcohol carries health risks at any level of consumption. What follows is not a health claim but a summary of what the scientific literature says, and above all of what it does not say. If you are looking for reasons to drink, this article gives you none.
Where the association comes from
Central Sardinia has the highest concentration of centenarians in the world. The term "Blue Zone" itself comes from the blue circles researchers drew on a map to mark these areas. Because those communities drink Cannonau daily, the link between the wine and longevity became common knowledge.
Common knowledge is not causation. But in this case, unlike many wine legends, there is actual research.
The study published in Nature
In November 2006 Roger Corder and his group at the William Harvey Research Institute, Queen Mary University of London, published a study in Nature that exposed human blood vessel cells to 165 different wines to identify which polyphenols had the strongest effect.
In summary:
- Procyanidins suppress the production of endothelin-1, the protein that constricts blood vessels
- Wines from the province of Nuoro and southwest France showed a two- to four-fold higher inhibitory effect and significantly higher oligomeric procyanidin levels than wines from Australia, Europe, South America and the United States
- In some cases levels were ten times higher; on average around five times
A later study by Tuberoso and colleagues measured a total phenolic content of 1,978 mg/L in Cannonau, with dose-dependent vasodilatory activity.
The explanation is not the grape, it is the method
This is the part almost everyone skips. Corder attributed the difference to the traditional production methods used in Sardinia and southwestern France, which ensure efficient extraction of procyanidins.
Procyanidins sit in the skins and the seeds. A long maceration extracts them, a short one does not. It is not Cannonau as a grape variety that carries those values: it is Cannonau vinified in a particular way. The same grape handled to make a ready, fruity wine contains far fewer.
The practical consequence is counterintuitive: two bottles carrying the same appellation can have very different phenolic compositions.
The figure nobody quotes
The Blue Zone literature reports a fact that undoes the simplistic reading: in the Sardinian Blue Zone people consume 79.3 litres of wine per person per year, against 89.6 litres in the rest of the island.
Where people live longest, they drink less, not more. Anyone presenting wine as the explanation for Sardinian longevity is ignoring the first available number.
Blue Zone research points to a set of factors: diet, daily physical activity tied to pastoral life, altitude, and social and family structure. Wine is one element of the picture, in moderate doses and within a meal. It is not the isolated variable.
What you can honestly take from it
The research says that some long-macerated red wines contain more procyanidins than others, and that procyanidins have a measurable effect on endothelial cells in the laboratory. It does not say that drinking wine makes you live longer, and neither does Corder.
If the subject interests you, the only sensible approach is to ask a producer how the wine was made, not whether it is "good for you". The first is verifiable; the second is a statement no serious producer can make.
A note about Immortale
Immortale is made in Gallura, in the northeast of the island, not in the Nuoro area studied by Corder. We have no analysis of the procyanidin content of our wine and therefore make no claim about it.
What we can state concerns method, and it is verifiable: six months in steel, three and a half years in oak barriques, two years resting in bottle. Six years before sale. That is a production fact, not a health promise.
Sources: Corder R., Mullen W., Khan N.Q., Marks S.C., Wood E.G., Carrier M.J., Crozier A., "Oenology: red wine procyanidins and vascular health", Nature 444, 566 (2006). Tuberoso et al., 2013. Pes et al., 2013.
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