Tag Archives: resveratrol

Is Grape Seed Extract as Healthful as Wine?

Patients ask me periodically if grape seed extract provides the same health benefit as judicious red wine.  Nobody knows with certainty.  The health benefits of red wine may be due to resveratrol.  Grape seed extract contains potentially healthy antioxidants called proanthocyanidins,

Many people don’t enjoy wine or other alcohol-containing drinks, and others just shouldn’t drink any alcohol.  Should they take a grape seed extract supplement or drink grape juice as a subsitute?  Again, it’s still unclear.  In 2009 I wrote a about a review article looking at the effect of various non-wine grape products and effects on heart disease risk.

A recent meta-analysis out of the University of Connecticut found improvement in two heart disease risk factors in those who take a grape seed extract supplement:

  • systolic blood pressure lower by 1.54 mmHg
  • heart rate lower by 1.42 beats per minute

No effect was seen on lipids (cholesterol and triglycerides), diastolic blood pressure, and C-reactive protein (a test of systemic inflammation).

Granted, these are tiny effects.  It’s unknown whether they, or other unknown effects of grape seed extract, would translate into clinical benefits such as fewer heart attacks and strokes, and longer lifespans.

Bottom Line

Grape seed extract and other non-wine grape products may be as beneficial as red wine in prolonging lifespan and preventing heart disease.  But we have much stronger evidence in favor of red wine and other alcohol-containing drinks.

Steve Parker, M.D.

 Reference:  Feringa, H.H.H, et al. The Effect of Grape Seed Extract on Cardiovascular Risk Markers: A Meta-Analysis of Randomized Controlled TrialsJournal of the American Dietetic Association, 111 (2011): 1,173-1,181.


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What Are Phytonutrients and What Have They Done For Me Lately?

Nutrition scientists think that plants have small amounts of numerous “bioactive compounds,” sometimes referred to as phytonutrients, that protect us against disease.

Many scientific studies have looked at groups of people over time, noting the various foods they eat as well as the diseases they develop.  These are called epidemiologic, ecological, or observational studies.  One finding is that lower rates of heart disease, vascular disease, and cancer are seen in people consuming plant-based diets.  “Plant-based” isn’t necessarily vegetarian or vegan.  The traditional Mediterranean diet, for example, is considered by many to be plant-based because meat, fish, and poultry are not prominent compared to plants. 

In contemplating what source of carbohydrates a person with diabetes should eat, I’ve been reviewing the scientific literature to see which sources of carbs might provide the biggest bang for the buck in terms of health and longevity benefits.

Here are some quotes from a 2002 review article in the American Journal of Medicine:

Phenolic compounds, including their subcategory, flavonoids, are present in all plants and have been studied extensively in cereals, legumes, nuts, olive oil, vegetables, fruits, tea, and red wine. Many phenolic compounds have antioxidant properties, and some studies have demonstrated favorable effects on [blood clotting] and [growth of tumors]. Although some epidemiologic studies have reported protective associations between flavonoids or other phenolics and cardiovascular disease and cancer, other studies have not found these associations.

Hydroxytyrosol, one of many phenolics in olives and olive oil, is a potent antioxidant.

Resveratrol, found in nuts and red wine, has antioxidant, [anti-blood-clotting], and anti-inflammatory properties, and inhibits [malignant tumor onset and growth].

Lycopene, a potent antioxidant carotenoid in tomatoes and other fruits, is thought to protect against prostate and other cancers, and inhibits tumor cell growth in animals.

Organosulfur compounds in garlic and onions, isothiocyanates in cruciferous vegetables, and monoterpenes in citrus fruits, cherries, and herbs have [anti-cancer] actions in experimental models, as well as [heart-healthy effects].

In summary, numerous bioactive compounds appear to have beneficial health effects. Much scientific research needs to be conducted before we can begin to make science-based dietary recommendations. Despite this, there is sufficient evidence to recommend consuming food sources rich in bioactive compounds. From a practical perspective, this translates to recommending a diet rich in a variety of fruits, vegetables, whole grains, legumes, oils, and nuts.

The article discusses phytoestrogens—plant chemicals that act in us like the female hormone estrogen—but effects are complex and I suspect we know much more now than we did in 2002 .  Soy products are the most well-known source of phytoestrogens.

The traditional Mediterranean diet is rich in all of the foods mentioned above, except for tea.  Even the Ketogenic Mediterranean Diet includes the aforementioned foods except for tea (I need to add tea and coffee), cereals, and cherries.

Steve Parker, M.D.

Reference:  Kris-Etherton, P.M., et al.  Bioactive compounds in foods: their role in the prevention of cardiovascular disease and cancer.  American Journal of Medicine, 113 (2002. Supplement 9B): 71S-88S.

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Filed under cancer, coronary heart disease, Fruits, Grains, Health Benefits, legumes, Mediterranean Diet, nuts, olive oil

Do Grape Products Other Than Wine Affect Heart Disease Risk?

"Grapes may be just as healthful as wine"

"Grapes may be just as healthful as wine"

Grape products favorably affect four risk factors for heart disease, according to a scientific review published last year.

The “French Paradox” refers to the fact that certain regions of France have low levels of heart disease despite high consumption of saturated fats that supposedly cause heart disease.  Some have explained away the paradox by noting high consumption of red wine in those areas, which could counteract the adverse effects of saturated fats.  Others have used the paradox to indict the Diet-Heart Hypothesis itself

Wine, especially red wine, is an integral part of the Ketogenic Mediterranean Diet.  However, many people just don’t like wine, and others shouldn’t be drinking it.  So, I’ve been wondering if grape products other than wine might have the healthy effects of wine.

The reference article below reviewed grape product trials published over the previous 13 years: 34 studies in animals, 41 in humans.  In addition to wine, grape products included grape juice, grape seed, grape skin, grape pomace, and polyphenol-rich extracts.  The authors conclude that grape products have the following beneficial effects on cardiovascular risk factors:

  • lower blood pressure, mainly due to release of nitric oxide from cells lining the arteries
  • reduced levels of total cholesterol, LDL cholesterol (“bad cholesterol”), and trigylcerides, especially if these values are high at baseline
  • reduced development of early-stage atherosclerosis (less LDL oxidation and plaque formation)
  • improved antioxidant status

Here are some grape product “fun facts” from the article:

  • healthy effects are primarily attributed to polyphenols, which are strong antioxidants that disable free radicals and chelate metals
  • major grape polyphenols are anthocyanins in red grapes, flavon-3-ols in white grapes
  • red grapes have more total polyphenols than white grapes
  • the main polyphenols in wine are resveratrol, tannins, flavan-3-ols, flavan-3,4-diols, anthocyanins, flavonols, flavones, anthocyanins, and anthocyanidins
  • red wine has a much higher phenolic content than white wine

Unfortunately, the authors never make any specific recommendations for people wanting to substitute alcohol-free grape products for wine.  

But I bet if you went down to your local vitamin or health food store, you could find some grape extracts or other grape products to try.  Anyone on a very low-carb diet would want to be sure the grape product wouldn’t supply more than 3-4 grams of digestible carbohydrate per day.  For those not on such a diet, purple grape juice like Welch’s—4 to 8 fl oz a day—is a good alternative to wine.  Welch’s has 42 g of carbohydrate per 8 fl oz. 

Steve Parker, M.D.

Disclaimer:  All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status.  Always consult your personal physician before making any dietary or exercise changes.

Reference:  Perez-Jimenez, Jara and Saura-Calixto, Fulgencio.  Grape products and cardiovascular disease risk factors.  Nutrition Research Reviews, 21 (2008): 158-173.

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Filed under Alcohol, coronary heart disease, ketogenic diet