Vitamins, minerals & supplements Archive

Ask the doctors

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Q. I've read that getting the flu shot annually will weaken my immune system over time. Is this true?

A. A study published in the March 1, 2017, issue of The Journal of Infectious Diseases investigated whether getting an annual vaccination against influenza (flu) can weaken your body's natural ability to protect itself from the disease. Past studies have raised similar concerns. Researchers at the University of Bergen in Norway followed 250 health care workers. Some of them got a flu vaccination every year from 2009 through 2013. The others only received the vaccine once in 2009 and not in the years from 2010 to 2013. The researchers then took blood samples before the influenza season (and before people were vaccinated that season), from the members of both groups and looked at different markers to gauge how well their immune systems would respond to the influenza virus. They found that getting an annual flu vaccination did not weaken the immune system. As a group, the people who got the flu shot annually appeared to have a better immune response to influenza than those vaccinated only once.

On call

Q. What is the significance of mild narrowing of the carotid artery detected by an ultrasound? I have never had any symptoms of stroke.

A. "Mild" narrowing ranges from 15% to 49% blockage of the artery. Over time, this narrowing can progress and lead to a stroke. Even if it doesn't progress, mild narrowing is a sign of early blood vessel disease and calls for preventive measures.

Weight loss can be challenging, but there are some strategies for success.

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If you're struggling to lose weight, you probably feel like the odds are stacked against you. You're not necessarily wrong.

"There is so much great-tasting food, and it's abundant and in your face all the time. To me it's kind of a miracle that people aren't even heavier than they are," says Dr. Meir Stampfer, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. In addition to an abundance of food, most people today also have a far more sedentary lifestyle than past generations. "Even active people who exercise a lot aren't expending the calories their ancestors did," says Dr. Stampfer.

Trying to cut back on calories by drinking diet soda or flavored sparkling water may not help with weight loss, and some research suggest it may actually lead to weight gain. But why, and what are the alternatives?

Worrisome levels of arsenic, lead, and other elements called heavy metals that can harm the developing brain are found in some commercial baby foods, according to a recent report. Here’s what parents should know and can do to protect young children.

Benzodiazepines and drugs with strong anticholinergic effects have been linked to Alzheimer's disease in people who take them. There are alternatives to both types.

Research we're watching

Widely considered the healthiest diet for your heart, the Mediterranean diet is rich in plant-based foods and features only small amounts of meat and dairy products. But a variation that includes more green plant foods may be even better for you, a small study suggests.

The study included 294 sedentary, moderately obese people whom researchers randomly divided into three groups. Each received different dietary advice: a standard healthy diet, a low-calorie Mediterranean diet, or a "green" Mediterranean diet. Both Mediterranean diet groups included about a quarter-cup of walnuts daily, and poultry and fish replaced beef and lamb.

Research we're watching

There are a number of different approaches to treating a condition called adhesive capsulitis, better known as frozen shoulder. This common condition causes significant shoulder pain and reduced mobility. While it generally goes away on its own over time, it can take up to a year or longer to heal. But there hasn't been consensus on whether any particular therapy leads to more rapid pain relief and full range of motion.

A study published online Dec. 16, 2020, by JAMA Network Open looked at various treatment options for frozen shoulder to determine which was the most effective. Researchers analyzed 65 different studies with more than 4,000 total participants and found that the first line of therapy should be to inject a steroid directly into the joint to reduce inflammation. This treatment helped to reduce pain and led to the fastest recovery. The study authors said the steroid injection should be accompanied by a home exercise program that includes stretches and exercises to improve range of movement in the shoulder.

News briefs

Hold off before you follow new recommendations to treat mild, persistent asthma — or at least consult your doctor first. The updated guidelines from the National Institutes of Health, published online in the December 2020 issue of The Journal of Allergy and Clinical Immunology, say it's okay for people with mild, persistent asthma to stop daily use of inhaled corticosteroids and instead use them only as needed, along with short-acting beta agonists ("rescue" medications). That's considered a major shift in guidance. But that may not be a good idea for some older adults, notes Dr. Anna Wolfson, an allergist and immunologist at Harvard-affiliated Massachusetts General Hospital. "A lot of people have a harder time with the occasional use of medications than a routine practice of daily use," she says. "And you may not want to decrease your asthma regimen during the pandemic. Poorly controlled asthma could lead to a flare or an ER visit, and perhaps an increased risk for complications if you develop COVID-19." Dr. Wolfson says there are some people who might benefit from using inhaled corticosteroids only as needed, but she urges you to speak with your doctor before changing your medication regimen.

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These drugs actually help stop dangerous blood clots from forming. Here's when you may need them.

Nearly everyone has heard of "blood thinners." Maybe you or someone you know takes one. But these drugs don't "thin" blood at all.

"They are actually anti-clotting drugs," says Dr. Gregory Piazza, a cardiologist with Harvard-affiliated Brigham and Women's Hospital. "They prevent potentially dangerous blood clots from developing in people at high risk, like those who have atrial fibrillation or a stent in a blood vessel, or who are immobile after surgery."