Can Wine Benefits Be Replaced by Eating Grapes?
The much trumpeted wine benefits may not be as great as we thought. A new study published in the Diabetic Medicine Journal revealed that among patients with type 2 diabetes, moderate alcohol consumption was associated with an increased risk of vision deterioration. Then, if wine benefits are questionable, shouldn’t we just concentrate on eating grapes to obtain the antioxidant benefits of this fruit?
The French paradox
In studies conducted in 1992, 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, 50 percent lower than in the Unites States, to the consumption of red wine. 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 -two 8 ounces glasses for men and 1 glass for women per day, red wine may increase HDL cholesterol, the “good” guy, decrease LDL cholesterol, the “bad” one, 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 nonnutritive 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 then 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 out that at the end of the red wine intake period, 4 weeks, LDL cholesterol and oxidized 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 defense 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 or 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 of red wine can be about 20 times higher 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 of white wine is required to produce an effect equal to red wine on 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?
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. In a study published by Atherosclerosis in May 2001, the researchers showed that both dealcoholized red wine and grape juice inhibit atherosclerosis in hamsters. This study, among others, showed that red grape juice and dealcoholized red wine can significantly reduce arterial disease by lowering the level of oxidized 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 dealcoholized red wine in inhibiting arterial disease at the same polyphenol dose. The researchers concluded that grape juice or non-alcoholic red wine are an excellent alternative to red wine when in comes to disease of the arteries.
A word of caution
If you are diabetic, grapes should be eaten in moderation. Their glycemic index is 53, which means this fruit is high in sugars. Grape juice glycemic index is 55.
Although past research has shown that in the absence of contraindications, moderate red wine drinking, two 8 ounces glasses for men and 1 glass for women per day, may be beneficial to patients who have a cardiovascular condition, those health effects disappear very fast even with moderate drinking. This may explain the serious health effects of drinking wine as in the case of eye deterioration for people with type 2 diabetes.
And since studies have indicated 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.
You can read the new study on the effect that moderate alcohol consumption may have in the eyes at News Medical Net
To your health!
Emilia Klapp, R.D., B.S.