Based on Roger Corder’s book, The Wine Diet (Sphere, UK, 2007).
The following paragraphs are based on talks held with Roger Corder and on the book he published in 2007. Professor Roger Corder is currently working at the Queen Mary’s School of Medicine in London. Readers who wish for further information, in particular the scientific details and references which have led Prof. Corder to come to such interesting conclusions on particular red wines are referred to his widely-available book. While based on sound scientific evidence, it is an easy, thought-provoking read, with fascinating information on food and health in general. Roger Corder’s research is also available on his website: http://www.the-red-wine-diet.com and I would like to thank here prof. Roger Corder for the re-reading of my summary.
WINE OVER THE CENTURIES
The Greeks. and indeed most probably long before them other more ancient people and tribes – some 10,000 years B.C. – drank wine and used it to prepare remedies, because wine is relatively stable and easy to keep. Should it degrade, it would turn into vinegar, an even more stable mixture. Water-based solutions are far less stable and rapidly become contaminated.
In the 13th century. Arnoldo da Villanova, a Catalan doctor and philosopher, recommended that wine be drunk with food but not between meals, which he reckoned was bad for one’s health.
In the 16th century. Paracelsus, a famous Swiss doctor, said that wine was both food and drink, remedy and poison: it was all a question of quantity. Indeed present-day medication can also “cure or kill”.
In the 19th century. Louis Pasteur (1822-1895) claimed that wine was the healthiest and most hygienic drink. Indeed in those days, the potable water we take for granted today, was very rare and it was far safer to drink wine than water stocked in unhygienic containers.
Later came the “Australian wine doctors”. In the days when people were emigrating to Australia in their thousands, they suffered miserably from scurvy and malnutrition during the long sea-journey, and many lost their lives. Doctor W. Redfern recommended travellers drink 140 ml of wine with a dash of lime juice. Lemons and limes were already known to help combat scurvy.
Dr Redfern started growing vines and making wine, followed by several other doctors who founded the first Australian wineries. On the basis of empirical evidence, many doctors sang the praises of wine and its health-promoting properties and treated all manner of physical and mental ailments with their own vintages.
The 20th and 21st centuries. brought scientific evidence to back up beliefs in the benefits of moderate alcohol consumption.
In the middle of the prohibition years, American biologist R. Pear, published an article connected with research on tuberculosis which stated that a reasonable consumption of alcohol was good for the health and that moderate drinkers lived longer than tea-totallers. While the deleterious effects of alcohol abuse were by then well-known, this was the first study that showed that a moderate consumption of alcohol was not at all unhealthy. This opinion was widely shared by the French.
The question remained as to which alcoholic drinks were beneficial.
STUDIES ON THE EFFECTS OF ALCOOL (WINE, BEER, SPIRITS)
It is well known that drinking alcohol in the evening raises the rate of HDL (good cholesterol) and lowers blood coagulation until the following day. Most studies show that white wine, beer and spirits, in moderate quantities, diminish the risk of cardio-vascular accidents and are not bad for the health. It is equally true that alcohol raises the blood pressure and thereby also the risk of strokes if drunk to excess. However, on the whole, research has shown that the risk is negligible and the beneficial effects considerable when alcohol is drunk in reasonable quantities.
Together with other dietary factors, a regular and moderate consumption of alcohol over a long period of time diminishes the risk of atherosclerosis and senile dementia. Experimental research has furthermore indicated that red wine inhibits atherosclerosis, regardless of its alcohol content.
Yet nothing is ever simple: other studies have shown that drinking wine, beer and spirits increases the risk of breast cancer. The research does not specify which kind of wine.
RED WINE: AN INTERESTING CASE
With regard to the overall reduction of untimely demise, and not only deaths due to cardio-vascular disease, red wine drinkers who drink between 2 and 4 glasses of wine a day have a 30% lower rate of mortality across the board, compared to those who do not drink or those who drink more than 4 glasses a day. Moderate drinkers come out as the winners, but heavy drinkers have the highest mortality risk.
These observations are most important, given that the combination of aspirin and clopidogrel (Plavix), which is known to be most efficient in preventing blood clots, only reduces by 30 % the risk of another attack among heart-disease sufferers.
Another study focusing on a population of over sixty-five-year-olds living at home in the southwest of France, has shown that those who drank wine (between 2 and 4 glasses in the case of red wine) were 25% less likely to suffer from dementia linked to vascular problems and Alzheimer’s disease. A similar study carried out in Denmark showed similar results: wine drinkers aged over 65 were less likely to suffer from dementia than non-drinkers and occasional drinkers.
On the other hand beer-drinkers appeared to be more likely to suffer from dementia, but this was attributed to their overall diet rather than to the alcohol.
In general it has been established that wine-drinkers eat more fruit, vegetables and fish, and less carbohydrates and saturated fats than other groups. They smoke less and are slimmer, take more exercise and are more educated. This indicates that wine-drinkers have a better and healthier life-style than beer and spirits drinkers. However studies have shown that the health enhancing effects are not only to be ascribed to the healthier life-style.
Indeed, a study carried out in the United States in 2005 showed that moderate consumption of alcohol lowered the risk of developing colon cancer. Further analysis showed that wine-drinkers were slimmer, ate more fruit and vegetables, took more exercise and smoked less: such habits are known to be beneficial against colon cancer.
A Danish study on a population of 28,463 men and women showed that the risk of contracting stomach cancer was lower among red wine drinkers, mainly as compared to non-drinkers and drinkers of other alcoholic drinks. Researchers concluded that two glasses of wine a day could prevent stomach cancer, and suggested polyphenols played an important part.
In short, apart from the increased risk of breast cancer among women, moderate consumption of wine (1 to 3 glasses a day) at mealtimes is generally thought to be beneficial.
Research must now determine the respective importance of a better diet, a healthier life-style and the chemical compounds found in wine, other than alcohol.
THE "FRENCH PARADOX "
In the last twenty-five years, medical interest in the health-promoting properties of a moderate consumption of wine has been considerable. Dr S. St-Léger and his team (The Lancet, 1979) showed that there was a converse correlation between wine consumption and death from cardio-vascular disease in Europe, North America and Australia. On the other hand, their research showed that the highest mortality risk was to be found in areas of North America, Australasia, Great Britain, Ireland, Finland and Norway, where beer and spirits are the traditional drinks. France was seen to be the country with the highest consumption of wine and the lowest mortality risk!
More surprisingly, French epidemiologists observed that among French people who ate large amounts of saturated fats (butter, foie gras, cassoulet, etc.), the risk of cardio-vascular disease was the lowest.
This phenomenon came to be known as the “French paradox”.
HOW DOES THE FRENCH PARADOX WORK?
The idea that regular consumption of wine could explain the French paradox was first aired by S Renaud and M. de Lorgeril, in 1991, the year in which they published an article in The Lancet. They suggested that alcohol had the ability to inhibit the formation of blood clots and that this could explain the protective effects of wine. This study met with great scepticism among experts and shocked a fair number of doctors and advocates of abstemiousness.
Roger Corder took a closer look at the French paradox. He took the view that this phenomenon was not a scientific aberration but that it revealed a fundamental aspect of dietetics and health which called for further research. He furthermore highlighted the fact that it was more of “southwest of France paradox” since, with regard to longevity, the proportion of people aged over 90 in the Gers was twice as high as the country’s mean average. These people did not have a particularly healthy diet: on the contrary. Roger Corder noted, however, that although they ate fat-rich meals including foie gras and cassoulet, they also drank local wines known to be very tannic, like Madiran, which is made from a variety known as Tannat.
ALL RED WINES ARE NOT EQUAL
Roger Corder then turned to other areas where the population is known to lead exceptionally long lives, like the highlands of Sardinia (Nuoro province), where the highest rate of centenerians in Europe occurred. This group does not benefit from the famous Mediterranean diet, because it is too far from the sea to be based on fish. Traditional meals include a lot of meat, cheese and pasta but are washed down with a very tannic wine, Sagrantino.
Professor Corder therefore inferred that very tannic red wines contributed to the remarkable longevity of the people of the Gers and the Nuoro, and that these wines must contain some natural compound that could explain the phenomenon. To this end he analysed the Madiran wines (Tannat variety), Sagrantino, and our Mondeuse noire very recently, and found them to contain very high rates of polyphenols, in particular procyanidins, compared to other wines. These wines are intense, robust, complex and their tannins contribute a long finish and good acidity.
According to all medical research, Corder noted, the regular consumption of wine is compatible with a healthy life-style and a number of scientific indicators show that it is healthier to drink red wine than not to drink any at all. However Corder adds that all wines are not equally beneficial and that their protective effects vary according to the area, the variety of grape and the way in which the wine is made. He suggests that the sometimes contradictory results of research into the efficacy of red wine may be due to the varying rates of procyanidins present in the wines. As aforementioned, the preventive effects as regards atherosclerosis have only been proven to be present in red wines, not in other alcoholic drinks.
IDENTIFYING THE SOURCE OF THE PROTECTIVE POWERS OF RED WINE
Several studies have shown that red wine has beneficial effects on the health of the heart by preventing fat from being deposited in the arteries, causing atherosclerosis. The same studies however also highlighted that not all red wines had this effect. This prompted research into identifying what exactly the active substance was, which varieties had the greatest amount of it, which growing methods enhanced the rates and whether any other fruit or any vegetables could offer a non-alcoholic alternative by offering the same benefits.
Obviously, in order to offer the same advantages, the alternatives must contain enough of the active substance to bring them on a par with 2 or 3 glasses of red wine.
POLYPHENOLS
These molecules are the main elements that shape the colour and taste of red wines. They are more commonly referred to as tannins. Wines that are beneficial to our health contain up to 3 g of polyphenols per litre. Polyphenol is a generic name which covers a wide range of phenolic compounds which present different structures and properties. Flavonoids and anthocyanins are the most common in red wines, the latter being responsible for the colour, and are mostly to be found in the pips and the skin of the grapes, respectively.
These polyphenols give red wines their astringent character. Over time and in the presence of oxygen, polyphenols interact and form long polymers known as condensed tannins. They are less soluble in the wine and may form deposits, as found at the bottom of bottles. During this process, wine loses some of its astringency, strength and colour.
White wines and rosés, which are made without the pips and skins, contain only very small amounts of polyphenols and have no significant antioxidant effects.
As a matter of fact, red wine polyphenols are more powerful antioxidants than vitamins C, E and A. Frankel and his team (The Lancet, 1993) and another research team (1998) showed in particular that polyphenols present in red wine inhibited the oxidation of LDL- cholesterol (bad cholesterol) which contributes to atherosclerosis.
This observation is significant and tends to demonstrate that the protective effects specific to red wines are not linked to the alcohol content. However other teams have been less assertive regarding the antioxidant properties of red wine polyphenols and their inhibiting effects on atherosclerosis.
THE POLYPHENOL BREAKTHROUGH
Procyanidins are the most common and most abundant polyphenols in young red wines. They can represent up to 1 or 2 g per litre, out of the total amount of polyphenols –usually some 3 g per litre.
The most significant breakthrough in the understanding of the role played by red wine polyphenols in protecting subjects from heart disease was made by DF Fitzpatrick and his team (1993). These researchers showed that wine made from Concord grapes (aVitis labrusca variety), very rich in polyphenols with a very unpopular foxy flavour, prompted vasodilatation linked to the endothelium (the layer of cells which line the inside of blood vessels) and limited the hardening of the arteries.
The interesting fact is that the wine from which the alcohol had been removed was more effective than the wine itself. In fact, similar results were obtained in patients suffering from heart disease (coronary diseases) who were given Concord grape juice to drink.
A few years later, Roger Corder and his team (Nature, 2001, 2006) purified and chemically identified the polyphenols present in a number of red wines, extract of grape pips and Concord grape juice. They demonstrated by means of in vitro experimentation that the molecules that were effective in protecting against heart disease were invariably procyanidins. Furthermore, the analysis of a wide variety of red wines showed that the beneficial effect of the wine was proportionate to the amount of procyanidins it contained. In comparison, resveratrol, a molecule that other teams suggested was the key element in red wine is present in far lower concentrations (a thousand times lower), which precludes its being effective among moderate drinkers. Corder’s studies also highlighted the reason behind discrepancies found in research on red wine: the variety of grape was not specified.
In fact, Corder and his team’s results brought credence to the idea that the consumption of red wine explained the French paradox, i.e. the fact that in spite of a diet rich in saturated fats heart disease was not so common.
HOW MUCH DOES IT TAKE?
In order to benefit from the protective effects of red wine, Corder suggests men drink 3-4 and women 2-3 125 ml glasses a day, with their evening meal or better still with their two main meals.
For instance, a person who eats 2 to 3 portions of fruit and drinks red wine is likely to absorb 1 to 2 g of protective polyphenols each day. Ideally the quantity of procyanidins should amount to some 300 to 500 mg a day.
WHY ARE SOME RED WINES HEALTHIER THAN OTHERS ?
Red wines that lack body and slip down easily also lack procyanidins because they are produced using modern techniques (fining, sterile filtering, etc). Besides Tannat, other grape varieties are also potentially procyanidin-rich, but the way in which they are grown and turned into wine significantly affects the outcome. Low yields, absence of fertilizers and the altitude at which they are grown may all contribute to raising the levels of procyanidins.
Traditional wine-making techniques produce very tannic wines, which suited drinkers in the past well, since they took wine with their meals and the astringency was considered perfectly acceptable. Nowadays, people want to drink wine at all times of the day and too much astringency is deemed aggressive to the palate and therefore unacceptable. However, mellow “easy” wines hardly contain any procyanidins and are less beneficial to one’s health.
The factors that affect procyanidin levels are:
WHO SHOULD ABSTAIN FROM DRINKING WINE AND ALCOOL IN GENERAL?
CAN ONE BENEFIT FROM PROCYANIDINS WITHOUT DRINKING WINE?
For a number of reasons, drinking wine at mealtimes is not necessarily everyman’s wish or pleasure, because of driving, professional demands, life-style, principles, etc. Eating procyanidin-rich fruit is a good alternative. Grape juice is not an appropriate alternative because the polyphenols contained in the pips and skin are extracted during the long fermentation necessary to produce procyanidin-rich wines. The only exception is the dark juice made from Concorde grapes.
However, a number of very common fruits contain high levels of procyanidins and therefore provide an easy alternative: red grapes, apples, cranberries, all dark-red and black berries, pomegranate seeds and walnuts.
Several studies have shown that people who eat flavonoïd-rich fruit tend to suffer less from heart disease and even cancer. Flavonoids are precursors of procyanidins. Their antioxidant properties are often thought to explain their beneficial effects. However, consuming therapeutic doses of vitamin C, E or A does not seem to be as beneficial. Scientists now believe that flavonoids interact specifically with enzyme systems and that this could explain the link between a flavonoid-rich diet and the beneficial effects observed. For his part, Roger Corder has indicated that procyanidins have a specific impact on blood vessels which is different from the effects of antioxidants.
IN SHORT
A diet rich in procyanidins and fruit and vegetables, regular exercise and, unless medically proscribed, 2-3 125 ml glasses of tannin-rich red wines is clearly conducive to a long and healthy lifespan – even one glass of red wine is beneficial.
We are delighted to say that our own Vens-le-Haut Mondeuse noire wine is rich in tannins and has one of the highest levels of procyanidins ever recorded.
Dr Georges Siegenthaler, PhD
1) Our Mondeuse wines (2004, 2005, 2006 and 2007 vintages) were analysed in Prof. Corder’s laboratory and were found to contain exceptionally high levels of procyanidins (See section entitled “Our vine varieties and our wines”).
The following paragraphs are based on talks held with Roger Corder and on the book he published in 2007. Professor Roger Corder is currently working at the Queen Mary’s School of Medicine in London. Readers who wish for further information, in particular the scientific details and references which have led Prof. Corder to come to such interesting conclusions on particular red wines are referred to his widely-available book. While based on sound scientific evidence, it is an easy, thought-provoking read, with fascinating information on food and health in general. Roger Corder’s research is also available on his website: http://www.the-red-wine-diet.com and I would like to thank here prof. Roger Corder for the re-reading of my summary.
WINE OVER THE CENTURIES
The Greeks. and indeed most probably long before them other more ancient people and tribes – some 10,000 years B.C. – drank wine and used it to prepare remedies, because wine is relatively stable and easy to keep. Should it degrade, it would turn into vinegar, an even more stable mixture. Water-based solutions are far less stable and rapidly become contaminated.
In the 13th century. Arnoldo da Villanova, a Catalan doctor and philosopher, recommended that wine be drunk with food but not between meals, which he reckoned was bad for one’s health.
In the 16th century. Paracelsus, a famous Swiss doctor, said that wine was both food and drink, remedy and poison: it was all a question of quantity. Indeed present-day medication can also “cure or kill”.
In the 19th century. Louis Pasteur (1822-1895) claimed that wine was the healthiest and most hygienic drink. Indeed in those days, the potable water we take for granted today, was very rare and it was far safer to drink wine than water stocked in unhygienic containers.
Later came the “Australian wine doctors”. In the days when people were emigrating to Australia in their thousands, they suffered miserably from scurvy and malnutrition during the long sea-journey, and many lost their lives. Doctor W. Redfern recommended travellers drink 140 ml of wine with a dash of lime juice. Lemons and limes were already known to help combat scurvy.
Dr Redfern started growing vines and making wine, followed by several other doctors who founded the first Australian wineries. On the basis of empirical evidence, many doctors sang the praises of wine and its health-promoting properties and treated all manner of physical and mental ailments with their own vintages.
The 20th and 21st centuries. brought scientific evidence to back up beliefs in the benefits of moderate alcohol consumption.
In the middle of the prohibition years, American biologist R. Pear, published an article connected with research on tuberculosis which stated that a reasonable consumption of alcohol was good for the health and that moderate drinkers lived longer than tea-totallers. While the deleterious effects of alcohol abuse were by then well-known, this was the first study that showed that a moderate consumption of alcohol was not at all unhealthy. This opinion was widely shared by the French.
The question remained as to which alcoholic drinks were beneficial.
STUDIES ON THE EFFECTS OF ALCOOL (WINE, BEER, SPIRITS)
It is well known that drinking alcohol in the evening raises the rate of HDL (good cholesterol) and lowers blood coagulation until the following day. Most studies show that white wine, beer and spirits, in moderate quantities, diminish the risk of cardio-vascular accidents and are not bad for the health. It is equally true that alcohol raises the blood pressure and thereby also the risk of strokes if drunk to excess. However, on the whole, research has shown that the risk is negligible and the beneficial effects considerable when alcohol is drunk in reasonable quantities.
Together with other dietary factors, a regular and moderate consumption of alcohol over a long period of time diminishes the risk of atherosclerosis and senile dementia. Experimental research has furthermore indicated that red wine inhibits atherosclerosis, regardless of its alcohol content.
Yet nothing is ever simple: other studies have shown that drinking wine, beer and spirits increases the risk of breast cancer. The research does not specify which kind of wine.
RED WINE: AN INTERESTING CASE
With regard to the overall reduction of untimely demise, and not only deaths due to cardio-vascular disease, red wine drinkers who drink between 2 and 4 glasses of wine a day have a 30% lower rate of mortality across the board, compared to those who do not drink or those who drink more than 4 glasses a day. Moderate drinkers come out as the winners, but heavy drinkers have the highest mortality risk.
These observations are most important, given that the combination of aspirin and clopidogrel (Plavix), which is known to be most efficient in preventing blood clots, only reduces by 30 % the risk of another attack among heart-disease sufferers.
Another study focusing on a population of over sixty-five-year-olds living at home in the southwest of France, has shown that those who drank wine (between 2 and 4 glasses in the case of red wine) were 25% less likely to suffer from dementia linked to vascular problems and Alzheimer’s disease. A similar study carried out in Denmark showed similar results: wine drinkers aged over 65 were less likely to suffer from dementia than non-drinkers and occasional drinkers.
On the other hand beer-drinkers appeared to be more likely to suffer from dementia, but this was attributed to their overall diet rather than to the alcohol.
In general it has been established that wine-drinkers eat more fruit, vegetables and fish, and less carbohydrates and saturated fats than other groups. They smoke less and are slimmer, take more exercise and are more educated. This indicates that wine-drinkers have a better and healthier life-style than beer and spirits drinkers. However studies have shown that the health enhancing effects are not only to be ascribed to the healthier life-style.
Indeed, a study carried out in the United States in 2005 showed that moderate consumption of alcohol lowered the risk of developing colon cancer. Further analysis showed that wine-drinkers were slimmer, ate more fruit and vegetables, took more exercise and smoked less: such habits are known to be beneficial against colon cancer.
A Danish study on a population of 28,463 men and women showed that the risk of contracting stomach cancer was lower among red wine drinkers, mainly as compared to non-drinkers and drinkers of other alcoholic drinks. Researchers concluded that two glasses of wine a day could prevent stomach cancer, and suggested polyphenols played an important part.
In short, apart from the increased risk of breast cancer among women, moderate consumption of wine (1 to 3 glasses a day) at mealtimes is generally thought to be beneficial.
Research must now determine the respective importance of a better diet, a healthier life-style and the chemical compounds found in wine, other than alcohol.
THE "FRENCH PARADOX "
In the last twenty-five years, medical interest in the health-promoting properties of a moderate consumption of wine has been considerable. Dr S. St-Léger and his team (The Lancet, 1979) showed that there was a converse correlation between wine consumption and death from cardio-vascular disease in Europe, North America and Australia. On the other hand, their research showed that the highest mortality risk was to be found in areas of North America, Australasia, Great Britain, Ireland, Finland and Norway, where beer and spirits are the traditional drinks. France was seen to be the country with the highest consumption of wine and the lowest mortality risk!
More surprisingly, French epidemiologists observed that among French people who ate large amounts of saturated fats (butter, foie gras, cassoulet, etc.), the risk of cardio-vascular disease was the lowest.
This phenomenon came to be known as the “French paradox”.
HOW DOES THE FRENCH PARADOX WORK?
The idea that regular consumption of wine could explain the French paradox was first aired by S Renaud and M. de Lorgeril, in 1991, the year in which they published an article in The Lancet. They suggested that alcohol had the ability to inhibit the formation of blood clots and that this could explain the protective effects of wine. This study met with great scepticism among experts and shocked a fair number of doctors and advocates of abstemiousness.
Roger Corder took a closer look at the French paradox. He took the view that this phenomenon was not a scientific aberration but that it revealed a fundamental aspect of dietetics and health which called for further research. He furthermore highlighted the fact that it was more of “southwest of France paradox” since, with regard to longevity, the proportion of people aged over 90 in the Gers was twice as high as the country’s mean average. These people did not have a particularly healthy diet: on the contrary. Roger Corder noted, however, that although they ate fat-rich meals including foie gras and cassoulet, they also drank local wines known to be very tannic, like Madiran, which is made from a variety known as Tannat.
ALL RED WINES ARE NOT EQUAL
Roger Corder then turned to other areas where the population is known to lead exceptionally long lives, like the highlands of Sardinia (Nuoro province), where the highest rate of centenerians in Europe occurred. This group does not benefit from the famous Mediterranean diet, because it is too far from the sea to be based on fish. Traditional meals include a lot of meat, cheese and pasta but are washed down with a very tannic wine, Sagrantino.
Professor Corder therefore inferred that very tannic red wines contributed to the remarkable longevity of the people of the Gers and the Nuoro, and that these wines must contain some natural compound that could explain the phenomenon. To this end he analysed the Madiran wines (Tannat variety), Sagrantino, and our Mondeuse noire very recently, and found them to contain very high rates of polyphenols, in particular procyanidins, compared to other wines. These wines are intense, robust, complex and their tannins contribute a long finish and good acidity.
According to all medical research, Corder noted, the regular consumption of wine is compatible with a healthy life-style and a number of scientific indicators show that it is healthier to drink red wine than not to drink any at all. However Corder adds that all wines are not equally beneficial and that their protective effects vary according to the area, the variety of grape and the way in which the wine is made. He suggests that the sometimes contradictory results of research into the efficacy of red wine may be due to the varying rates of procyanidins present in the wines. As aforementioned, the preventive effects as regards atherosclerosis have only been proven to be present in red wines, not in other alcoholic drinks.
IDENTIFYING THE SOURCE OF THE PROTECTIVE POWERS OF RED WINE
Several studies have shown that red wine has beneficial effects on the health of the heart by preventing fat from being deposited in the arteries, causing atherosclerosis. The same studies however also highlighted that not all red wines had this effect. This prompted research into identifying what exactly the active substance was, which varieties had the greatest amount of it, which growing methods enhanced the rates and whether any other fruit or any vegetables could offer a non-alcoholic alternative by offering the same benefits.
Obviously, in order to offer the same advantages, the alternatives must contain enough of the active substance to bring them on a par with 2 or 3 glasses of red wine.
POLYPHENOLS
These molecules are the main elements that shape the colour and taste of red wines. They are more commonly referred to as tannins. Wines that are beneficial to our health contain up to 3 g of polyphenols per litre. Polyphenol is a generic name which covers a wide range of phenolic compounds which present different structures and properties. Flavonoids and anthocyanins are the most common in red wines, the latter being responsible for the colour, and are mostly to be found in the pips and the skin of the grapes, respectively.These polyphenols give red wines their astringent character. Over time and in the presence of oxygen, polyphenols interact and form long polymers known as condensed tannins. They are less soluble in the wine and may form deposits, as found at the bottom of bottles. During this process, wine loses some of its astringency, strength and colour.
White wines and rosés, which are made without the pips and skins, contain only very small amounts of polyphenols and have no significant antioxidant effects.
As a matter of fact, red wine polyphenols are more powerful antioxidants than vitamins C, E and A. Frankel and his team (The Lancet, 1993) and another research team (1998) showed in particular that polyphenols present in red wine inhibited the oxidation of LDL- cholesterol (bad cholesterol) which contributes to atherosclerosis.
This observation is significant and tends to demonstrate that the protective effects specific to red wines are not linked to the alcohol content. However other teams have been less assertive regarding the antioxidant properties of red wine polyphenols and their inhibiting effects on atherosclerosis.
THE POLYPHENOL BREAKTHROUGH
Procyanidins are the most common and most abundant polyphenols in young red wines. They can represent up to 1 or 2 g per litre, out of the total amount of polyphenols –usually some 3 g per litre.
The most significant breakthrough in the understanding of the role played by red wine polyphenols in protecting subjects from heart disease was made by DF Fitzpatrick and his team (1993). These researchers showed that wine made from Concord grapes (aVitis labrusca variety), very rich in polyphenols with a very unpopular foxy flavour, prompted vasodilatation linked to the endothelium (the layer of cells which line the inside of blood vessels) and limited the hardening of the arteries.
The interesting fact is that the wine from which the alcohol had been removed was more effective than the wine itself. In fact, similar results were obtained in patients suffering from heart disease (coronary diseases) who were given Concord grape juice to drink.
A few years later, Roger Corder and his team (Nature, 2001, 2006) purified and chemically identified the polyphenols present in a number of red wines, extract of grape pips and Concord grape juice. They demonstrated by means of in vitro experimentation that the molecules that were effective in protecting against heart disease were invariably procyanidins. Furthermore, the analysis of a wide variety of red wines showed that the beneficial effect of the wine was proportionate to the amount of procyanidins it contained. In comparison, resveratrol, a molecule that other teams suggested was the key element in red wine is present in far lower concentrations (a thousand times lower), which precludes its being effective among moderate drinkers. Corder’s studies also highlighted the reason behind discrepancies found in research on red wine: the variety of grape was not specified.
In fact, Corder and his team’s results brought credence to the idea that the consumption of red wine explained the French paradox, i.e. the fact that in spite of a diet rich in saturated fats heart disease was not so common.
HOW MUCH DOES IT TAKE?
In order to benefit from the protective effects of red wine, Corder suggests men drink 3-4 and women 2-3 125 ml glasses a day, with their evening meal or better still with their two main meals.
For instance, a person who eats 2 to 3 portions of fruit and drinks red wine is likely to absorb 1 to 2 g of protective polyphenols each day. Ideally the quantity of procyanidins should amount to some 300 to 500 mg a day.
WHY ARE SOME RED WINES HEALTHIER THAN OTHERS ?
Red wines that lack body and slip down easily also lack procyanidins because they are produced using modern techniques (fining, sterile filtering, etc). Besides Tannat, other grape varieties are also potentially procyanidin-rich, but the way in which they are grown and turned into wine significantly affects the outcome. Low yields, absence of fertilizers and the altitude at which they are grown may all contribute to raising the levels of procyanidins.
Traditional wine-making techniques produce very tannic wines, which suited drinkers in the past well, since they took wine with their meals and the astringency was considered perfectly acceptable. Nowadays, people want to drink wine at all times of the day and too much astringency is deemed aggressive to the palate and therefore unacceptable. However, mellow “easy” wines hardly contain any procyanidins and are less beneficial to one’s health.
The factors that affect procyanidin levels are:
- the vineyard (old vine-stocks, low yields, altitude i.e. UV exposure, slow and long ripening);
- the variety (smaller grapes with a lot of pips which contain polyphenols) Tannat and Mondeuse noire are known to contain the highest levels of procyanidins;
- the vintner’s methods (long fermentation – three weeks or longer are necessary to obtain good levels of procyanidins; conversely, fining to lower astringency and too much filtering substantially lowers procyanidin levels);
- the maturing process (ideally, to ensure good protective effects, young wine should be drunk – centenarians, who are no great connaisseurs, drink their wine straight out of the barrel; however if the young wine contains high levels of procyanidins, it will still be fairly rich in them after a period of five years if it has been stored properly – after ten years, though, its value seen from the procyanidin angle is virtually nil.
WHO SHOULD ABSTAIN FROM DRINKING WINE AND ALCOOL IN GENERAL?
- Women who are pregnant should refrain from drinking alcohol as it has been proven that the foetus’s blood then contains the same levels of alcohol as the mother’s and this has deleterious effects on the baby’s development, especially in the first stages of pregnancy.
- People who are taking prescribed or non-prescribed medication that alcohol could interact with.
- People who have trouble limiting their consumption and have a history of addiction.
- People who drive vehicles or use machinery.
CAN ONE BENEFIT FROM PROCYANIDINS WITHOUT DRINKING WINE?
For a number of reasons, drinking wine at mealtimes is not necessarily everyman’s wish or pleasure, because of driving, professional demands, life-style, principles, etc. Eating procyanidin-rich fruit is a good alternative. Grape juice is not an appropriate alternative because the polyphenols contained in the pips and skin are extracted during the long fermentation necessary to produce procyanidin-rich wines. The only exception is the dark juice made from Concorde grapes.
However, a number of very common fruits contain high levels of procyanidins and therefore provide an easy alternative: red grapes, apples, cranberries, all dark-red and black berries, pomegranate seeds and walnuts.
Several studies have shown that people who eat flavonoïd-rich fruit tend to suffer less from heart disease and even cancer. Flavonoids are precursors of procyanidins. Their antioxidant properties are often thought to explain their beneficial effects. However, consuming therapeutic doses of vitamin C, E or A does not seem to be as beneficial. Scientists now believe that flavonoids interact specifically with enzyme systems and that this could explain the link between a flavonoid-rich diet and the beneficial effects observed. For his part, Roger Corder has indicated that procyanidins have a specific impact on blood vessels which is different from the effects of antioxidants.
IN SHORT
A diet rich in procyanidins and fruit and vegetables, regular exercise and, unless medically proscribed, 2-3 125 ml glasses of tannin-rich red wines is clearly conducive to a long and healthy lifespan – even one glass of red wine is beneficial.
We are delighted to say that our own Vens-le-Haut Mondeuse noire wine is rich in tannins and has one of the highest levels of procyanidins ever recorded.
Dr Georges Siegenthaler, PhD
1) Our Mondeuse wines (2004, 2005, 2006 and 2007 vintages) were analysed in Prof. Corder’s laboratory and were found to contain exceptionally high levels of procyanidins (See section entitled “Our vine varieties and our wines”).
