I have always liked eating potatoes, but I feel they have gotten a bad reputation as being high in calories and offering few nutrients. Is it worthwhile eating white or red potatoes, or should one stick with sweet potatoes, which are regarded as very good for you? - F.W., via e-mail Judy Siegel-Itzkovich comments: The Mayo Clinic Health Letter has dealt with this issue. The truth is that if you skip the high-fat toppings such as sour cream, cheese and butter and don't fry them, potatoes need not be avoided in a healthful diet. A medium-sized potato baked in its skin has just 160 calories. None of those calories are from fat, cholesterol or refined sugar. The average potato has 37 grams of carbohydrates. But, potatoes are also a great source of vitamin C, with a medium-sized one having 22 milligrams. They are a superb source of potassium, providing 952 mg. of this important nutrient, which is considerably more than is in a banana or a serving of broccoli or spinach. Potatoes are a good source of protein, too, providing four grams, which is comparable to a half a cup of milk. In addition, that medium-sized potato provides 1.9 mg. of iron. Most of the nutrients are found in or just under the potato skin. Thus, to maintain all the nutrients, it is best to avoid peeling. The peels also have four grams of fiber. I am a 50-year-old man. My low-density lipoprotein (LDL cholesterol) is at the lower levels of the normal range, which is good, but my high-density lipoprotein (HDL, or the good cholesterol) is below the minimum recommendation. I exercise and eat mostly a healthful diet. Is there any specific food or food supplement that I can eat to raise my HDL levels? - T.M., Arad Olga Raz, chief clinical dietitian of the Tel Aviv Sourasky Medical Center, comments: When total cholesterol and LDL cholesterol are relatively low, it is not surprising that HDL cholesterol may also be lower than recommended. Try to eat daily three tablespoons of olive oil added to your food. You can also drink a glass of dry red wine three to seven times a week. There are some people, especially men, who naturally have low levels of HDL. Sometimes it is because of a genetic predisposition, stress, food or high triglycerides. Try the oil and wine and see what happens. If it helps, that is good, as they are frequently beneficial. It they don't, be aware that many people with low HDL live healthily and happily for many years. I was in the cosmetic department of a large department store in Kfar Saba testing lipsticks on the back of my hand when the assistant suggested I try them on my lips. Is it a common practice to use the tester lipstick directly on the mouth, possibly transmitting germs from previous testers? - S.S., via e-mail Dr. Itamar Grotto, head of the Health Ministry's public health services, replies: We have not issued guidelines and have no research on the subject, but clearly, it is not recommended to use the same lipstick that has been used before on many mouths. A while back I wrote to you concerning my daughter's high level of testosterone. Due to her hormonal imbalance she suffered from acne. Dr. Julian Schamroth, a veteran Jerusalem dermatologist who answered, was 100 percent correct when he diagnosed her from afar as having PCOS (polycystic ovarian syndrome). She went on the medication Androcur, and her acne over a period of time completely went away. However, her hormonal imbalance still causes her problems. Over the last few years, she has been losing hair. Now the situation is so severe that she looks bald in some areas. She has been to dermatologists, endocrinologists and her gynecologist, but none has helped her. She has tried all kinds of shampoos, oils and vitamins, but nothing seems to stop the balding. Is it possible to take hair from her younger sister and have it transplanted to the few balding spots? Where would Dr. Schamroth suggest we go to deal with this issue? - M.G., Herzliya Dr. Julian Schamroth responds: The hair loss that is associated with PCOS is usually the last to respond to Androcur therapy. In fact, it may take 18 to 24 months of it to correct this problem. I would simply suggest perseverance and patience. Shampoos, vitamins, minerals and oils are simply a waste of time (and they tend to cost a fortune). A hair transplant from a second person would not be successful, and it is not done. Rx for Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx for Readers, The Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel-Itzkovich at (02) 538-9527, or e-mail it to firstname.lastname@example.org, giving your initials, age and residence.