DEAR DR. GOTT: A while back, you published an article about eye twitching. I, too, have had eye-twitching problems and did consult a doctor. He suggested getting a shot in my temple, but I declined, it being so close to my eye. I read somewhere that soy was good for the nervous system, so I bought lecithin concentrate, 400 milligrams, and now take one in the morning and one at night. As long as I take them, I do not get the twitching. If I stop taking them, within a day or two, it starts again. I've been using the lecithin for a number of years now, and just the two tablets are still sufficient. Thank you for your informative column.

DEAR READER: There are two main types of lecithin: egg and soy. Soy lecithin is extracted from soybean oil and used as a food and drug additive, typically an emulsifier. It is becoming more popular as a dietary supplement. It is purported to benefit many conditions, such as high cholesterol, gallbladder disease, Alzheimer's disease, eczema, anxiety and more. Soy, in general, has not been studied extensively in regards to claims that it will treat, improve, or cure certain health conditions. Soy protein is known to be a good alternative to animal protein and is beneficial to maintaining health, however. There are no established dosing guidelines simply because not enough research has been done. Some studies have noted diarrhea, nausea and abdominal pain and fullness as side effects. If it works for you, stick with it. Others who want to try this should speak with their physicians first. Be sure to keep track of when the supplement was started and make note of any improvements, side effects or reactions, even if they seem unrelated. This is especially important if you are on other medications, over-the-counter or prescription, as well as other supplements, vitamins or herbs. DEAR DR. GOTT: I read your article about hives. The writer said her problem began after having bilateral knee replacements. I'm just wondering if the hives could be caused by an allergic reaction to any of the materials used in her knee replacements. Before my knee replacement, I was asked if I had any known allergies to metals, nickel in particular. I wish the writer the best and hope she has found the source of the problem. DEAR READER: I am sure that the writer was also asked about any known allergies; however, perhaps the problem lies in something that she did not know. Nickel allergy is most commonly associated with jewelry, particularly inexpensive gold-plated pieces. If the reader doesn't wear any or wears only high-quality jewelry, she may not have known. Allergies can also develop suddenly to substances that were previously handled without a problem. I am printing your letter because you bring up an excellent point in that the hives may be directly caused by the knee replacement and a resulting allergy. Thank you for writing. Readers who are interested in learning more about allergies can order my Health Report "Allergies" by sending a self-addressed stamped No. 10 envelope and a $2 check or money order to Newsletter, P.O. Box 167, Wickliffe, OH 44092-0167. Be sure to mention the title or print an order form off my website's direct link at www.AskDrGottMD.com/order_form.pdf.

Dr. Peter H. Gott is a retired physician and the author of several books, including "Live Longer, Live Better," "Dr. Gott's No Flour, No Sugar Diet" and "Dr. Gott's No Flour, No Sugar Cookbook," which are available at most bookstores or online. His website is www.AskDrGottMD.com.

Copyright 2011, United Feature Syndicate, Inc.