Archive for November, 2015

What does sleep do for us?

DEAR DOCTOR K: Everybody sleeps, but why is that? What does sleep do for us?

DEAR READER: I get this question a lot, and we've talked about it before in this column. There is some new information that is interesting. The honest answer is that we don't know why it is we sleep. We spend about a third of our lives doing it, so nature must have a reason for it. But it's hard to ask nature questions -- or, at least, to get an answer. One possible reason for sleep is obvious: Our muscles may need the rest. However, the heart is a muscle, and it doesn't rest while we sleep, thank goodness. And like our heart, many of our other organs, such as the liver and kidneys, keep working.

Will melatonin supplements help with jet lag?

DEAR DOCTOR K: My wife and I are traveling to Europe in a few weeks, and we're already dreading the jet lag. Do you think melatonin will help?

DEAR READER: Many people find that crossing several time zones makes their internal clocks go haywire. Some small studies have suggested that melatonin can help jet lag if taken a few days before and after travel. Melatonin is a natural substance released by our brain to help coordinate our circadian (day/night) rhythm. This rhythm is disturbed when we travel across time zones. Melatonin is more effective in minimizing the effects on sleep of eastward travel.

Can you really boost your immune system?

DEAR DOCTOR K: I hear that doctors are trying to boost the immune system to help people fight cancer. Does that actually work?

DEAR READER: Yes, this old, simple idea is beginning to work. The job of the immune system is to recognize when "foreign" things (such as microbes or chemicals) enter our bodies and eliminate them. Cancerous cells make substances that look foreign to the immune system. So, a person's immune system should be an ally in fighting cancer.

Do adults need milk?

DEAR DOCTOR K: My parents made us drink milk every day, and I've continued that as an adult. A friend just told me that adults don't need milk, and that it can even be bad for you. What's the truth?

DEAR READER: Like you, we always had milk when I was a kid. In fact, the coming of the milkman to deliver the milk at home (remember him?) was an important event each day. These days, I have milk on cereal, but I don't drink it by the glass. As with most things, there are both benefits and risks.

How long might hot flashes last?

DEAR DOCTOR K: Recently you wrote about a patient who was still having hot flashes in her early 70s, long after menopause. I'm in my 60s, and I still have them. How long might they last?

DEAR READER: Following the publication of that column, I got many letters with questions like yours. These letters also described what it is like to suffer from hot flashes. One reader recalled driving with her parents on a bitter cold winter night. Suddenly, her mother had a hot flash. It was so bad that she "turned the heater off, opened the car windows and stuck her head out the window. My father asked her what the heck she was doing."

What is the Mediterranean diet and is it actually healthy for you?

DEAR DOCTOR K: In some of your columns you've said that the "Mediterranean diet" is healthy. First, what is a Mediterranean diet? Second, what proof is there that it really is healthy? Call me "Skeptical."

DEAR READER: Well, "Skeptical," prepare yourself for a fairly emphatic reply. Because when I think skepticism about something important is misguided, I tend to unload. The Mediterranean diet is the traditional diet of people in countries near the Mediterranean Sea. The diet is rich in plant foods. These include fruits, vegetables, grains, beans, nuts and seeds. Animal protein is consumed chiefly in the forms of fish and poultry. Olive oil is the principal fat. And wine is taken with meals.

Remarkable stem cell experiments hold great promise

DEAR READERS: In yesterday's column I said that, theoretically, embryonic stem cells could be used to replace cells that are killed by disease -- heart cells killed in a heart attack, for example, or brain cells killed by Alzheimer's disease. If you needed stem cells, what you would ideally want were your own embryonic stem cells. The dilemma: Your own stem cells existed only briefly, long ago, and you couldn't turn back the clock. That is, until a research breakthrough in 2007 showed that you could.

Has anything come of stem cell research?

DEAR DOCTOR K: People have been talking about stem cells as a revolutionary technique for a long time. Has anything come of it? And why has it been so controversial?

DEAR READER: You're right; people have been excited about stem cells for nearly 25 years. Yet progress was quite slow, and some people had major ethical concerns. But in the past eight years, progress has accelerated and the ethical issues largely have been circumvented. Theoretically, stem cells could be used to replace cells that are killed by disease -- heart cells killed in a heart attack, or brain cells killed by Alzheimer's disease. But to explain the exciting potential of stem cells, I need first to define some terms and concepts.

Should I be worried about complications from a hip replacement?

DEAR DOCTOR K: My doctor says I need hip replacement surgery. She says it will help my pain. But I'm worried about complications. Should I be?

DEAR READER: I get a lot of questions about hip replacement surgery, and I'm in a good position to answer them: I had a hip replacement about a decade ago. Before I give a more detailed answer, let me cut to the chase: The benefits of hip replacement surgery greatly outweigh the risks.

What are good fats and bad fats?

DEAR DOCTOR K: I've read in your column about "good fats" and "bad fats." I've also heard that recent studies challenge which fats are "bad." Can you shed a little light on this issue?

DEAR READER: I don't blame you for being confused. One problem with medical studies is that they don't always agree. That's why we often need a lot of them to determine the "truth." Let's start at the beginning. For years, you probably heard that all fats were bad for you and carbohydrates ("carbs") were good. That was nonsense. We need both fats and carbs in our diet.