DEAR READERS: In yesterday's column, I answered a reader's question about why doctors seem to change their minds about the best treatments for medical problems. I said that we doctors keep changing our minds because we're human. We sometimes believe things that seem reasonable and for which there is some evidence. But then we find out, as more and better research is done, that we were wrong.
DEAR DOCTOR K: I have diabetes, and my doctor used to tell me my fasting blood sugar level needed to be below a certain number. Now, he says it's OK if it's higher. Why do doctors keep changing their minds about the right thing to do?
DEAR READER: We doctors keep changing our minds because we're human. Which means that we sometimes believe things that seem reasonable and for which there is some evidence -- only to find out, as more and better research is done, that we were wrong.
DEAR DOCTOR K: A friend heard about a study that said a person's immune system changes with the seasons. That seems incredible to me. But if it's true, it's fascinating. Do you know what she is talking about?
DEAR READER: I think I know the study she is referring to. Before describing what it found, it's worth talking a bit about the immune system and also about genes.
DEAR DOCTOR K: It seems like several years ago all my friends were taking antioxidant pills. Now I don't hear about antioxidants as much. Are they worth taking?
DEAR READER: Here's what we know, and here's what is still controversial. The cells of our body are full of chemicals interacting with other chemicals. In the process of getting the energy they need to survive and carry out their functions, cells naturally produce chemicals called "free radicals." Just as political free radicals can sometimes damage society, chemical free radicals can damage body tissues.
DEAR DOCTOR K: I'm a woman in my 50s, and every so often it is painful for several days when I urinate. The doctor tests me, says I don't have a urinary tract infection, and that there's nothing to do. It's true that it goes away, but I'd like some relief when it hurts. Is there anything I can do?
DEAR READER: Urinary tract infections are a common cause of painful urination, but there are other causes as well. And those other causes can be treated. Here's what you need to know before you talk again to your doctor.
DEAR DOCTOR K: I've heard that drinking red wine, or any alcoholic beverage, in moderation is "heart-healthy." Is it true, and is red wine any healthier than other alcoholic beverages?
DEAR READER: There are many studies of the two questions you ask. As for the first question, most studies have found that moderate drinkers are less likely to develop Type 2 diabetes and heart disease. That's when moderate drinkers are compared either to non-drinkers or to heavy drinkers.
DEAR DOCTOR K: I know that the Mediterranean diet is supposed to improve heart health. Recently I heard it also improves brain health. Is that pretty well established? Of all the organs I want to protect, my brain is "numero uno."
DEAR READER: I agree with your priorities regarding organs: My brain is "numero uno," too. And I do think the evidence is strong that the Mediterranean diet does protect the brain. This diet emphasizes fruits, vegetables, grains, beans, nuts, fish, poultry, olive oil and wine.
DEAR DOCTOR K: I'm a 68-year-old man who has been feeling more tired and less "sexy" over the past several months. My doctor says my blood testosterone level is normal, but "low normal" -- a little bit above low. I know that some men take testosterone gel as a treatment for this. My doctor is not so keen on that. What's your opinion?
DEAR READER: I don't know nearly enough about your health or your symptoms to offer you personal advice. But I'll tell you what I think research has shown, at least so far. I'll warn you: It is a controversial area, and I reserve the right to change my mind as new research is published.
DEAR DOCTOR K: A while back, you commented on a study that said getting cancer was mainly caused by bad luck. You said you thought the study was wrong. Then recently, I heard that another study agreed with you. Can you explain?
DEAR READER: In April 2015, I responded to a question about a study from a famous cancer researcher. The media had interpreted the study to say that getting cancer was just a matter of "bad luck." In other words, there was not much people could do to protect themselves against getting cancer.
DEAR DOCTOR K: Last year, a truck ran a red light, totaled my car and nearly totaled me. I spent several weeks in the hospital. Since then my body has healed, but I'm not myself. I'm very irritable, easily angered and sleeping poorly. A friend says I have PTSD, but I thought that occurred to people -- soldiers, for instance -- exposed to repeated threats.
DEAR READER: Your friend is astute. Post-traumatic stress disorder -- PTSD -- is a condition in which distressing symptoms occur after a major trauma. While the media often talk about PTSD in soldiers who have seen active combat, you don't have to be in battle to get PTSD. A single horrible event, like a bad auto accident, can surely do it.