Wednesday’s Ask Dr. Walt — Immune Boosters for COVID (the flu and the cold, Part 1)

Dear Dr. Walt,

I know you support natural medicines (herbs, vitamins, and supplements) that are safe and effective for various conditions. So, what are your thoughts about the cornucopia of over-the-counter products being hawked to boost our immune system to prevent or treat infections such as COVID-19, influenza, and the common cold? — Concerned in Colorado

THIS IS PART 1 of a Two-Part Answer.

Dear Apprehensive,

One of the best reviews I’ve read on the subject comes from a well-trusted, objective, and consumer-centered resource, Consumer Reports, which said, “Over the years, countless dietary supplements, alternative remedies, and foods have been touted as immune-system boosters. In fact, more than 1,000 supplements currently on the U.S. market are claimed to have a positive effect on immunity.”

The advertising is working, as the fourth most common reason that both people from 18–54 years of age take natural medicines (herbs, vitamins, or supplements) is for “immune health,” “immune support,” or to boost “immune response.” Between 25% and 30% of these folks take them every single day, representing 40 million Americans in 2018. Unfortunately, they’re wasting their hard-earned dollars.

Each of us must contend with a never-ending onslaught of potentially dangerous germs. We’re protected from most by our immune system. “The idea of boosting your immunity is enticing; however, the concept of boosting immunity actually makes little sense scientifically,” wrote Harvard Health. “The immune system is precisely that — a system, not a single entity.” They added, “For now, there are no scientifically proven (products to enhance) immune function.”

Because consumers are becoming more aware that natural medicines have not been shown to boost the immune system, makers are increasingly using terms like “fine-tuning the immune system,” “supporting immune health,” or “supplementing immune modulators.” The Natural and Alternative Treatments™ Encyclopedia opined, “Does such a treatment exist? No … although claims abound.”

Harriet H. Hall, MD, an editor and weekly contributor to the Science-Based Medicine blog ( and a contributor to the QuackWatch publication, is more explicit: “Do our immune systems need help? Walk into any health foods store. Browse the Internet. You will find a multitude of dietary supplements advertised to ‘boost your immune system,’ or ‘support immune function.’ Do they work? Will they keep you healthier or reduce your chances of catching infectious diseases? … Their claims are not supported by science. For normal people whose nutrition is adequate, no high-quality clinical study has ever shown that any intervention led to any meaningful improvement in immune function or to any decrease in the rate of disease.”

So, buyer beware! Even with the limited scope of regulations on natural medicines, if there are in fact no studies showing they work to significantly reduce the risk of disease or illness, then you’d be right to expect plenty of false advertising. And, you’d be correct.

According to Dr. Hall, “The FDA and the FTC have been cracking down on dubious ‘immune-boosting’ product claims.” Popular products charged with “unsubstantiated” or “false” advertising include AirShield® Immune Boosting” Supplement, Emergen-C®, Airborne® Effervescent Health Formula, and Dannon® Company’s yogurt products.

As a result of these actions, advertisers and supplement makers are changing their tactics and increasingly saying there is plenty of evidence in animals and humans that their product has been shown to “boost immune response.”

They’re correct that there is indeed some supporting research. However, these studies almost exclusively measure this or that blood level of immune components (like infection-fighting immunoglobulin or white blood cells) but do not show improvement of the immune system as a whole.

Even more importantly, these studies have not shown any positive clinical outcomes with COVID or leading to less influenza or fewer colds.

For example, as I was writing this column, a study in Korea among 99 healthy adults (average age 50) was published. Those who took Korean red ginseng twice daily for eight weeks had improved immune systems, with increased numbers of germ-fighting T cells, B cells, and white blood cells, compared to placebo. However, there was no reduction in the number of colds that occurred.

What’s the bottom line? I’ll answer that question in Part 2 of this article Friday.

You can pre-order the book here

© Copyright WLL, INC. 2021 This blog provides a wide variety of general health information only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment from your regular physician. If you are concerned about your health, take what you learn from this blog and meet with your personal doctor to discuss your concerns.

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