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11 February 2010

Drink to a healthy heart

When researchers first discovered that red wine could protect our hearts, wine lovers rejoiced. Now research is showing that red grape juice could be just as beneficial.

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A few years ago, it was observed that in southern France mortality rates from heart disease were lower than expected – despite the consumption of diets high in saturated fat.

Researchers attributed the impressive low incidence of heart disease to the consumption of red wine. And since then, the possibility that drinking red wine might protect our heart arteries has made the topic “wine and health” extremely popular.

In fact, research has shown that, taken in moderation (i.e. two 240ml glasses for men and 1 glass for women per day), red wine may increase "good" HDL cholesterol, decrease "bad" LDL cholesterol, prevent oxidation of LDL, and scavenge free radicals.

What is the secret in red wine?

Since the discovery of the "French Paradox" puzzle in 1992, researchers have been trying to pinpoint why red wine has a cardiovascular protective effect.

While studies have been focusing in the antioxidant properties of red wine, evidence suggests other mechanisms by which it might be beneficial for our health.

Research points toward a family of substances called polyphenols which are found in plants and are abundant in grapes. Polyphenols are part of a larger family known as phytochemicals.

Phytochemicals: medicine of the future

The word "phyto" means "plant" in Greek. Phytochemicals are non-nutritive chemicals found in plants that protect us against diseases.

Many fruits and vegetables contain a wide variety of phytochemicals. In fact, researchers have identified by now more than 900 different phytochemicals in foods and they are not done yet, since every day they discover new ones.

It is estimated that there may be more than 100 different phytochemicals in just one serving of fruit or vegetables.

Studies have long shown that phytochemicals are present in plants to protect them, but only recently we have learned that they are also crucial in protecting humans against diseases. We know that people who consume plant foods regularly have a lower incidence of heart disease than people who do not include them in their diet.

How can phenol-phytochemicals protect our arteries?

Polyphenols can protect our arteries through the following mechanisms:

  • Lowering LDL cholesterol in the blood. A study conducted to evaluate the effect of moderate Sicilian red wine consumption on cardiovascular risk factors found that at the end of the red wine intake period (4 weeks), LDL cholesterol and oxidised LDL had significantly decreased, while HDL Cholesterol and the total antioxidant capacity of the blood had increased.
  • Recycling vitamin E as an antioxidant. This is very important because vitamin E represents the first line of defence against LDL oxidation. Once vitamin E is exhausted, LDL cholesterol is no longer protected until the vitamin can be reactivated by agents such as polyphenols.
  • Increasing the production of nitric oxide, a substance that causes the arteries and veins to relax.
  • Preventing platelets from sticking to the inside walls of the arteries. Platelets are tiny particles found in the blood that play an important part in the clotting process.

Red vs white wine

White wines have shown the ability to prevent the oxidation of LDL, but generally are not as effective as red wines.

Polyphenol content can be about 20 times higher in red wine than in white wine and it has been observed in several studies that the antioxidant potential of red wine is six to ten times higher than white wine.

About eight times more white wine is required to produce an effect equal to red wine in preventing the oxidation of LDL cholesterol. Three factors account for these results:

  • Grape skins are not included in the production of white wine.
  • Red wine is made with whole grapes, including skins.
  • The skins of red grapes contain higher amounts of polyphenols than the skins of white grapes.

Wine or grapes for healthy arteries?

If the polyphenols in grapes are mostly in the skins, can we just have red grapes or red grape juice, which is also made with the grape skins, and obtain the same beneficial effects as drinking red wine?

Yes, we can, researchers tell us.

One study showed that red grape juice and dealcoholised red wine can significantly reduce arterial disease by lowering the level of oxidised cholesterol, preventing platelets to stick together, and enhancing the production of nitric oxide.

In another study, grape juice proved to be more effective than red wine or dealcoholised red wine in inhibiting arterial disease at the same polyphenol dose. The researchers concluded that grape juice and non-alcoholic red wine are excellent alternatives to red wine when it comes to disease of the arteries.

The bottomline

Although research has shown that, in the absence of contraindications, moderate red wine drinking may be beneficial to patients who have a cardiovascular condition, those health effects disappear very fast and can have serious health implications when we abuse drinking.

Since studies indicate that most of the beneficial effects of drinking red wine are attributable to the polyphenols present in grapes, we may conclude that a diet that includes grapes as well as other fruits and vegetables containing polyphenols may be even more beneficial.

References:
1. G Avellone, G, Di Garbo, V, Campisi D, De Simone R, Ranel G, Scaglione R and LicataG. Effects of moderate Sicilian red wine consumption on inflammatory biomarkers of atherosclerosis European Journal of Clinical Nutrition (2006) 60, 41–47. doi:10.1038/sj.ejcn.1602265.
2. Ruf JC. Alcohol, wine and platelet function. Biol Res. 2004;37(2):209-15.
3. Vinson, JA, Teufel, K, Wu, N. Red wine, dealcoholized red wine, and especially grape juice, inhibit atherosclerosis in a hamster model. Atherosclerosis. 2001 May; 156(1):67-72.
4. Folts, JD. Potential health benefits from the flavonoids in grape products on vascular disease. Adv Exp Med Biol. 2002; 505:95-111.

[This is an extract from the book “Your Heart Needs the Mediterranean Diet”, written by Emilia Klapp. The author is a graduate in Nutrition Science and is certified as a Registered Dietician by the American Dietetic Association. For more information about the author and the book and to obtain a list of the 10 top Mediterranean foods, visit www.emiliaklapp.com]

(www.emiliaklapp.com /Health24, updated January 2009)

 
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