Diabetic Mediterranean Diet

"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.