Dear Doctor: News coverage of a study recently suggested that frequent, moderate drinking could ward off Type 2 diabetes. Could this be true?

Dear Reader: You're right to distrust alcohol. Excessive use can increase the risk of multiple cancers as well as cirrhosis of the liver, nerve damage both peripherally and within the brain, weakened heart muscle and abnormal heart rhythms. It also can lead to traffic deaths and an addiction that destroys lives. However, small to moderate alcohol consumption has been shown to decrease the rate of heart attacks -- and also may help control blood sugar.

A recent Danish study analyzed 2007 and 2008 survey data on alcohol consumption from 28,704 men and 41,847 women. Survey participants were separated into different groups: no history of alcohol consumption; prior consumption but none in the last year; less than one day of alcohol consumption per week; one to two days of alcohol consumption per week; three to four days of alcohol consumption per week; and five to seven days of alcohol consumption per week.

After almost five years, the data showed that lifetime abstainers had a higher rate of Type 2 diabetes than other groups. The lowest rate was seen among those who drank alcohol three to four days per week. In fact, compared to people who consumed alcohol less than once per week, those men were 27 percent less likely to develop diabetes, and the women were 32 percent less likely to develop diabetes.

But before you take another sip of wine, let us parse the data a little. In the study, female abstainers were twice as likely to be obese when compared to women who drank alcohol three to four days per week or five to seven days per week. In men, this rate was about 50 percent greater. Similarly, male and female abstainers were twice as likely to be physically inactive when compared to the frequent alcohol users. Moreover, abstainers had a greater family history of diabetes and were more likely to be less educated. (The authors said they adjusted for these factors and, to some degree, they did.)

A 2012 European study found similar results. After controlling for the fact that people who consumed no alcohol were more likely to be inactive, obese and less educated, the authors showed that women who drank 1 unit of alcohol per day were slightly less likely to develop diabetes compared to women who drank 1 unit every two to eight days. For men, the connection between alcohol consumption and lowered diabetes risk was considered less significant.

Lastly, an analysis of 20 studies in 2009 showed that, in men, the protective benefit of alcohol was greatest at 22 grams of alcohol (about 1 1/2 glasses of wine) per day. In women, 24 grams of alcohol per day was most protective. But the authors didn't adjust their findings based on weight, physical activity or educational level.

Note that the European studies analyzed populations in which consumers of alcohol had generally higher rates of physical activity, which reduces the risk of diabetes; that may not hold true in the United States. But in summary, alcohol consumption -- though it has a myriad of problems -- does seem to be linked to a slight decrease in the risk of diabetes.

(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. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My husband was recently hospitalized for pneumonia "of undetermined origin" and treated with IV antibiotics. Does that mean they don't know whether it was viral or bacterial? Are antibiotics used for both? I'm also worried that he might have a relapse.

Dear Reader: The word "pneumonia" refers to inflammation of the lungs, specifically the small air sacs, called alveoli, which sit in clusters at the far edges of the bronchial tree. These air sacs provide the surface area for the oxygen that you inhale to move from the lungs into the bloodstream and throughout the body.

When the air sacs become inflamed, they fill with fluid. People with pneumonia can often hear a crackling sound deep within their lungs as they draw a breath. The presence of that fluid not only makes it hard to breathe, it also prevents adequate oxygen from getting to all parts of the body. Additional symptoms include high fever, cough and chills.

Most often, pneumonia occurs due to some type of infection. The agent can be viral, as in influenza, or bacterial, as with Staph or Strep. More rarely the cause can be fungi, or chemical agents. Pneumonia can affect one or both lungs, and can be asymptomatic, which means you don't even realize you have it. That's commonly referred to as "walking pneumonia."

Differentiating between a virus and a bacterium as the cause of pneumonia can be a challenge. We go by a review of each patient's vital signs and symptoms, the results of chest X-rays, nasal swabs to look for flu viruses and sputum cultures to check the secretions in the lungs. Then we weigh all the evidence to arrive at the best determination.

Since your husband was treated with IV antibiotics, it means that his care team concluded the cause of his pneumonia was bacterial. Antibiotics are not used to treat viral pneumonia. Instead, the approach is supportive care -- rest, fluids, nutrition and time.

When we treat bacterial pneumonia, we don't always find the specific bug that's the cause. If we're lucky, we can pinpoint it through a blood culture or sputum sample. But in many cases, we choose the antibiotic we think will be most effective and monitor its progress.

More than 900,000 people in the United States become ill with pneumococcal pneumonia each year, which is the most common type of bacterial pneumonia. To help combat the Streptococcus (pneumococcus) bacteria, the American Lung Association recommends that children younger than 5 and adults over 65 receive a pneumococcal vaccination series.

Pneumonia in and of itself isn't contagious. However, as with a cold or the flu, a cough or sneeze by someone with pneumonia can spread the organisms that caused it. If your husband is feeling better after the course of antibiotics is complete, then they have done their work.

Should he relapse, which is known as recurrent pneumonia, his care team will likely want to evaluate further. In older patients, we always worry about cancer. And recurrent pneumonia can be a sign of a weakened immune system. In any case, an important part of his recovery is taking things slow for a few weeks, even when he feels like he's back to normal.

(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. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My mother and father have hypothyroidism, as do my two younger sisters. Now I've been experiencing symptoms that would indicate thyroid problems. My doctor checked my T3 and TSH levels, but did not check T4, and said I did not need medication. Shouldn't she also have checked my T4?

Dear Reader: Your question suggests that you've done some homework. Good job! As you know, hypothyroidism is the term used when the thyroid gland doesn't produce enough thyroid hormone. The condition is quite common, occurring in about 4.6 percent of the population. Further, it's five to eight times higher in women than men.

The most common cause of hypothyroidism is Hashimoto's thyroiditis, a slow autoimmune attack of the thyroid gland that leads to decreased production of thyroid hormone. Genetic susceptibility can indeed play a role in an autoimmune attack of the thyroid, meaning having one family member with hypothyroidism increases an individual's risk of hypothyroidism. Because you have multiple family members with hypothyroidism, I can understand your concern about developing this disease.

Measuring the level of TSH, thyroid-stimulating hormone, is a very good test for hypothyroidism. TSH, which is produced by the pituitary gland, stimulates the thyroid to produced thyroid hormone. Alternatively, in a feedback mechanism, the thyroid hormones T3 and T4 suppress secretion of TSH. So, if your thyroid hormone levels are high, your TSH level should be low, and if your thyroid hormone levels are low, your TSH level should be high.

In other words -- because of the feedback mechanism -- when you have hypothyroidism, your TSH should be higher than normal. Because the feedback mechanism is slow to change the level of TSH, the TSH level gives an indication of your overall thyroid status over many weeks. One caveat with TSH is that it increases as you get older, meaning that people over the age of 80 can have higher TSH levels, but not be considered hypothyroid. Because your TSH is normal, I would think that hypothyroidism is of low likelihood.

But let's take a closer look at T4 and T3. The thyroid produces these hormones in response to TSH; 80 percent of the hormones produced by the thyroid is T4, and only 20 percent is T3. The latter is a much more active thyroid hormone, with three to five times the effect of T4 and a much shorter half-life. That means its levels vary more than T4 levels from one day to the next. Also, T3 drops substantially with illness. It's true that T4 can be a more precise test for thyroid hormone status, but in your case I don't think there is additional value in checking T4 because both your TSH and T3 levels are normal.

That said, while your thyroid function on these tests are currently within range, your doctor should continue to monitor them because your family history puts you at increased risk of hypothyroidism. Be aware, however, that severe illness can affect the levels of TSH, T4 and T3, so thyroid function assessments are not accurate under those circumstances. At those times, checking a reverse T3 may be helpful.

Finally, keep in mind that the symptoms of hypothyroidism (fatigue, constipation, cold intolerance, weight gain and dry skin) can be caused by many other conditions. It's certainly smart to have your thyroid checked when you have these symptoms, but if your thyroid is normal, you should probably consider a broader evaluation.

(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. Owing to the volume of mail, personal replies cannot be provided.)