Will multiple sclerosis affect my pregnancy?

DEAR DOCTOR K: I have multiple sclerosis. My husband and I would like to have a baby. What do I need to know before I get pregnant?

DEAR READER: Multiple sclerosis (MS) is a disease that affects communication between nerve cells in the brain and spinal cord and the rest of the body. This results in symptoms that may include fatigue, weakness, pain and trouble with movement. In the most common form of the disease, sudden worsening of symptoms (flare-ups or relapses) alternate with symptom-free periods (remissions)

What do you think of the new statin guidelines?

DEAR DOCTOR K: My doctor never recommended statins to me, but he says there are new guidelines, and thinks that I should now start taking one. What do you think of the new statin guidelines?

DEAR READER: The new guidelines make a lot of sense, because we've learned that statins have more effects on the body than just lowering cholesterol. Statins were developed after a Nobel Prize-winning discovery in the 1970s revealed how the body makes cholesterol. Most of the cholesterol in our body is made by our body, not consumed in our food. Statins slow the production of LDL ("bad") cholesterol by the body.

What could cause male infertility?

DEAR DOCTOR K: My wife and I have tried to get pregnant for over a year. We're going to be tested soon to see if anything is wrong. I'm worried that the problem lies with me. What are some reasons for a man to be infertile?

DEAR READER: About one in seven couples in the United States is unable to conceive a child after trying for one year. The infertility is caused by either the man alone (about 40 percent of the time), by the woman alone (about 40 percent of the time) or by both partners (about 20 percent of the time). So it is possible that something about you is responsible for your wife's difficulty with becoming pregnant.

Could artificial sweeteners actually cause weight gain?

DEAR DOCTOR K: For 20 years, I've substituted artificial sweeteners for sugar in my coffee, and switched to diet soft drinks to avoid obesity and the diseases that overweight people are prone to, like Type 2 diabetes. Now I hear that new research says that's a bad idea. What is going on?

DEAR READER: Here's what's not confusing: More than a modest amount of sugar each day is not good for you. Nothing's changed there. The sweet tooth that many of us have (I plead guilty) leads us to eat too much sugar.

Could stem cells be used to treat Type 1 diabetes?

DEAR DOCTOR K: My teenage daughter has had Type 1 diabetes since she was 8 years old. Fortunately, exercise, a good diet and insulin treatments have kept her healthy. I recently heard of a breakthrough at Harvard that might someday cure Type 1 diabetes. Can you explain?

DEAR READER: The research you're referring to was conducted in the Harvard laboratory of Dr. Douglas Melton. Like you, Dr. Melton has a child with Type 1 diabetes. When his child became sick, he redirected his laboratory to the goal of finding a cure.

Is there a treatment or vaccine being created for Ebola?

DEAR DOCTOR K: Like everyone, I'm afraid that the Ebola virus could spread in the United States. There must be research underway to find treatments, and vaccines to prevent it in the first place. Please tell me there is.

DEAR READER: Infection with the Ebola virus is indeed frightening. In West Africa, the site of the latest outbreak of Ebola, more than half the people who have become infected with it have died. I doubt there will be an epidemic of Ebola in the U.S. and other developed nations, but there have been cases, and there will be more.

Should I stop taking niacin to raise my HDL cholesterol?

DEAR DOCTOR K: For years I've taken niacin to raise my HDL cholesterol. Now my doctor wants me to stop. Why?

DEAR READER: When we talk about cholesterol, we're generally referring to low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol. LDL is also known as "bad" cholesterol. When there is more LDL than necessary in the bloodstream, the LDL cholesterol burrows inside blood vessel walls. It slowly forms plaques of atherosclerosis. When those plaques rupture and block blood flow, they cause heart attacks and strokes.

What are phytonutrients?

DEAR DOCTOR K: You've mentioned phytonutrients in a few recent columns. What are they? And what can they do for our health?

DEAR READER: Let's begin by breaking "phytonutrients" into its two parts. First, "nutrients." These are chemicals in our environment that we need to get inside our body, usually through eating foods that contain them. Nutrients are a necessary part of our body chemistry. Indeed, many are necessary for the life of most living things.

Is there evidence the HPV vaccine has real benefits?

DEAR DOCTOR K: My daughter's pediatrician would like her to have the HPV vaccine. I'm not sure. Is there evidence the HPV vaccine has some real benefit?

DEAR READER: Yes, there is evidence -- overwhelming evidence. And with this vaccine, the benefit is not that it will reduce the risk of a short-lived illness, like the flu. This vaccine will reduce your daughter's risk of getting a common and life-threatening cancer. Human papillomavirus (HPV) is the main cause of cervical cancer and genital warts

What is diabetic nephropathy?

DEAR DOCTOR K: I have diabetes. My doctor says I'm at risk for diabetic nephropathy. What is that? What can I do to prevent it?

DEAR READER: Diabetic nephropathy is kidney disease that is a complication of diabetes. Your kidneys are made up of hundreds of thousands of small tubes that filter your blood and help remove waste from your body. In people with poorly controlled diabetes, these structures thicken and become scarred. Over time, the kidneys lose their ability to remove waste products from the blood.