Don't believe products that claim to boost immunity
Q: I guess everyone wants a strong immune system. But is there anything to the claims of products that advertise that they boost immunity?
A: In a word, no. Our immune system does a remarkable job of protecting us from bacteria, viruses and other microbes. That's good, because they can cause disease, suffering, even death. It seems logical to want to give your immune system a boost.
The problem is that "boosting your immune system" is a simplistic concept. In reality, our immune system is incredibly complex, composed of many different types of cells that make many different types of chemicals.
To function well, the immune system requires balance and harmony. Think of it as an army: The actions of the soldiers need to be coordinated by the generals, who determine when and where to attack, as well as when to stop attacking.
You can't "boost" all parts of the immune system at once, and you probably don't want to. An overactive immune system is seen in major autoimmune diseases, such as Type 1 diabetes, rheumatoid arthritis, multiple sclerosis and lupus.
In autoimmune diseases, overactive parts of the immune system start attacking the body instead of defending it.
Allergies are another example of an immune system that's overactive. A little harmless pollen gets into your nose, for example, and the immune system overreacts. And you start sneezing and getting a runny nose that won't quit.
There is still much that researchers don't know about the workings and interconnectedness of the immune response. We've got to understand how the immune system works better than we currently do to achieve the goal of boosting just the right part, at just the right time, and in just the right part of the body.
As for the many food products and packaged drinks that are labeled as "supporting immunity," "boosting immunity" or providing a "defense" against germs? Rubbish!
Most of these products just contain vitamins and minerals that people already get as part of a normal, healthy diet.
Some of them have been shown to boost one small part of the immune system, in a laboratory dish. That's not proof that they will help you fight off infections any better.
My colleague Dr. Michael Starnbach, a professor of microbiology and medical genetics at Harvard Medical School, feels strongly that when it comes to products that claim to boost immunity, there's no truth in advertising.
As he says, there's simply no evidence that consuming these products will translate into better immune function. And without that evidence, the packaging claims are just a marketing ploy.
Eating or drinking those "immune boosting" foods won't help you, and may lead you to consume more calories than you need.
It's not silly to want to find a way to help the immune system do a better job of defending us from foreign microbes, and I hope that research can teach us how to do this. However, we just don't have enough information yet to make this a reality.
• Dr. Komaroff is a physician and professor at Harvard Medical School. For questions, go to AskDoctorK.com.