Dear Doctor: I read your recent response to a question about alcohol consumption and its correlation to breast cancer. But what about the risk once you've been diagnosed? I was recently diagnosed with breast cancer and have completed radiation. I am on medication and have a very positive prognosis. I enjoy a glass of wine occasionally and am wondering if I should continue doing this. You talked about two units of alcohol every three or four days as being acceptable. What exactly are two units, and would this be OK for someone in my situation?

Dear Reader: For those who missed my previous column, let me repeat: The relationship between alcohol consumption and breast cancer has been studied multiple times, and there does appear to be a link. Studies have shown that this link is dose-responsive, meaning the more you drink, the greater the risk of developing breast cancer. The correlation between breast cancer and heavy or binge drinking is the most definite.

In the prior article, I also referred to a positive benefit of alcohol for women, in that research has found that having one drink (two units of alcohol) every three to four days was linked to a significant decrease -- 17 percent -- in death during the course of one study.

As for whether there is an association between alcohol consumption and cancer recurrence or a new cancer after a breast cancer diagnosis, that has been studied as well. A 2016 article in the journal Cancer Treatment Reviews analyzed results from 16 studies to assess breast cancer risk and alcohol consumption in women who had previously been diagnosed with breast cancer. Eleven of the studies looked at recurrence of the original breast cancer, and five studies looked at another new breast cancer developing. The women in the studies were followed for five to 18 years.

Some studies showed no correlation, but the results of the combined studies did show a small connection between alcohol intake and a recurrence of breast cancer. The correlation was found even among those who drank one unit of wine every day -- that's half a standard glass, to answer your question about units of wine. Alcohol also had a greater effect upon women after menopause and women who were obese. However, the five studies that looked at new breast cancers did not show an effect from alcohol.

It is difficult to make an overarching conclusion from this data, but there does appear to be some correlation between alcohol and an increased risk of breast cancer recurrence. However, this correlation was not seen in women who drank alcohol less frequently then one drink every other day. So in regard to breast cancer, it's likely safe to have a glass of wine (two units of alcohol) every three days, as this amount doesn't seem to be linked to an increased risk of new or recurrent breast cancer.

But please make sure to continue your regular follow-ups of evaluations with mammograms.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

Dear Doctor: I've been reading about a new illness that's a lot like polio and is making children in parts of the country very sick. What is it, and should my family and I be worried?

Dear Reader: You're referring to acute flaccid myelitis, also known as AFM, a rare neurological disease that affects the spinal cord. The symptoms mimic those of polio, which has helped to push AFM into the headlines.

Before we get into specifics, we want to stress that AFM is quite rare. Despite the sudden spate of alarming news reports that have, quite understandably, caused you concern, the rate of infection is extremely low -- one person per million. As of last November, there were 120 confirmed cases of AFM in the United States in 2016.

So what exactly is AFM?

It's a syndrome that can cause the muscles and reflexes in the body to stop working normally. Symptoms often arise quickly. What begins as a fever or respiratory illness gives way to weakness in the limbs, including a possible loss of muscle tone.

In several reported cases, the first symptom in a child diagnosed with AFM was a sudden limp. Some patients have slurred speech or facial drooping. In the most serious cases, acute weakness in the muscles that control breathing has led to respiratory difficulties.

At this time, the causes of AFM are not fully understood. Officials at the Centers for Disease Control and Prevention suspect a range of viruses may be involved. These include West Nile virus, enteroviruses that enter the body through the intestines, and adenoviruses, which can cause coldlike symptoms, including sore throat, bronchitis, pneumonia, diarrhea and pink eye.

Research into the causes of AFM, which affects children in greater numbers than adults, is a national priority. At the CDC, scientists and public health specialists are gathering blood samples as well as fluid specimens from the nose, respiratory tract and spinal cord of affected patients for testing. Results are collected into a database for study and analysis.

The symptoms of AFM are similar to several other conditions that are far more common. This has increased the challenge of arriving at an accurate diagnosis. However, awareness of the disease among health care providers is growing rapidly, which means that diagnosis and reporting are become more accurate.

If you believe you or your child has symptoms that correspond with those of AFM, call your family doctor. The findings from a careful examination of the nervous system, with accurate mapping of the muscles and reflexes affected, and diagnostic tests such as an MRI and analysis of the cerebrospinal fluid, will allow a correct diagnosis.

Several germs are suspected in AFM, so the CDC recommends that your family is up-to-date on polio and all other recommended vaccinations, and that you protect yourself and your family from mosquito-borne viruses by using insect repellents.

The good news is that increased awareness of AFM is leading to an ever-larger volume of reliable data for researchers to work with. That means more information about what causes the disease, and more avenues in which to seek and find a cure.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

Dear Doctor: Does outlook really matter when it comes to lifespan, as a recent study suggested? I'm not a wet blanket, but I don't have a relentlessly sunny disposition either.

Dear Reader: Let's say it's a gray, cloudy Monday morning. You're stuck in traffic, listening to the news of another atrocity in some distant land. Such a scenario would not in itself arouse feelings of optimism. Instead, an optimistic person might focus on feeling excited about his or her job, realize that the traffic is going to get better, and take solace in the fact that humanitarian efforts will be made to stop further atrocities.

In my own experience, I've seen pessimistic, unhappy people lead very long lives, and I've seen optimistic people's lives cut short by illness. That doesn't mean that, in the aggregate, optimism has no effect on lifespan.

Specific studies have looked for correlations between an optimistic outlook and cardiovascular disease, finding mortality benefits among those who had a more optimistic attitude. These studies used different scales to judge a person's level of optimism, with one common approach using a questionnaire about a person's approach to life. Some, for example, asked people to respond in either agreement or disagreement to statements such as, "Overall, I expect more good things to happen than bad."

A combined evaluation of many studies assessing the connection between optimism and physical health was reported in the Annals of Behavioral Medicine in 2009. Researchers measured physical health outcomes by rates of cancer, heart disease, infection rates, pain, diabetes and kidney failure. In the combined evaluation, the authors found a small correlation between better physical health and optimism, and an even smaller correlation between lower death rates and optimism.

A more recent study published in 2016 in the American Journal of Epidemiology followed 70,000 nurses and judged levels of optimism by how they responded to a questionnaire called the Life Orientation test. The women responded to 10 different statements such as, "In uncertain times, I usually expect the best," "I rarely count on good things happening to me," and "I'm always optimistic about my future."

The researchers ranked women into four quartiles, from lowest to highest, and found that those who were most optimistic had a 26 percent decrease in the death rate over the study period compared to those who were the least optimistic. This was after adjusting for depression, because some people who aren't optimistic may actually be depressed. The decrease in death rates was seen for deaths caused by cancer, strokes, heart attacks and infections.

One problem with the study is that women who were the most optimistic had lower smoking rates, were more physically active, had more education and were more likely to be married. Each of these factors is associated with greater longevity. The authors say they adjusted for these factors, but fully adjusting for them is difficult. Another problem with the study is that the study might not reflect correlations within the general population, in that 97 percent of the women identified themselves as white.

Overall, the study found what appears to be a correlation between optimism and a better cholesterol level, higher blood levels of antioxidants and improvements in one's immune system.

My own feeling is that optimism is less about sunniness than about hopefulness. This hopefulness helps people get through the bad times, because they realize that good times are ahead. And, overall, such people seem to have healthier habits that can help lead to greater longevity.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)