DEAR DR. BLONZ: How much does the grade of olive oil (extra-virgin, virgin, etc.) have to do with the fatty-acid proportions and other health values?
DEAR F.M.: The most prevalent component in olive oil is oleic acid, which is an 18-carbon-long monounsaturated fatty acid. Most of the oleic acid will be present as part of a triglyceride, where three separate fatty acids are attached to the compound glycerol. (This is where the word "triglyceride" comes from.)
Higher grades of olive oil have only a small amount of free fatty acids -- those not attached to a triglyceride -- which is referred to as "acidity" on the product label. The lower the acidity, the better. The International Olive Oil Council states that extra-virgin olive oil must have no more than 0.8 percent acidity, and virgin olive oil can have no more than 2 percent acidity.
In the big scheme of things, this type of grading has little to do with the proportion of monounsaturated, saturated and polyunsaturated fatty acids. The health value of olive oil goes beyond its high percentage of monounsaturates. The olive contains active phytochemical substances, which are nature's way of protecting the olive's fats from attack. These substances, which include polyphenols and tocopherols, are present primarily in extra-virgin oil, which is the first oil to come out during pressing.
DEAR DR. BLONZ: Why is alcohol present in so many cough and cold medicines? Does it have any role in the effect of the medicine?
DEAR D.S.: I have written in the past that there is evidence of a beneficial health effect from a moderate consumption of alcohol. A moderate intake is considered to be one to two drinks per day, with a drink defined as a 4-ounce glass of wine, 12-ounce glass of beer or 1-ounce shot of hard liquor. But the presence of alcohol in some medications has nothing to do with health. The alcohol is there because it's an excellent solvent, and it serves as a vehicle to keep certain types of medications in solution.
DEAR DR. BLONZ: Are less expensive domestic wines as good for the heart as fine French red wines?
DEAR S.C.: Research studies on the benefits of wine have come from both sides of the Atlantic, and I am not aware of any study performing a head-to-head comparison. I'd think it safe to assume that the wine made from similar grapes in both areas would have comparable effects. An important point not to lose sight of is that a person's overall diet and lifestyle carry more weight in determining one's state of health than any possible contribution alcohol might make.
Kensington resident Ed Blonz has a Ph.D. in nutrition from UC Davis. Email him at email@example.com.