The word “boosted” also falsely implies that we might want to multiply the number of immune cells we have, Dr. Knoedler says. “We don’t want more immune cells. We just want the ones we have to be able to function normally and carry out their primary roles,” Dr. Knoedler says. And the idea that we would want to supercharge our immune response doesn’t make sense given that overactive immune responses can cause excessive amounts of inflammation that make people feel terribly ill, Kaplan points out. So, “What you really want is a competent immune response,” Kaplan says.
OK, so semantics aside, is there anything that’s proven to make your immune system more competent? Better at its job? The truth is there is a serious lack of data behind most things you see being touted as immune boosters. “A lot of these ads for supplements and superchargers and quick fixes…these things have never been tested in clinical trials,” Kaplan says. (The FDA does not evaluate or regulate supplements the way it does drugs.)
“When we look at data on vitamins and herbal supplements and their impacts on viral infections as a whole, most of them have not been shown to [have an] impact,” Dr. Knoedler says. At best, “Sometimes something shows some very small benefit in one study, but it doesn’t in another [study].” (An example is Vitamin D.) There’s also a lot of variation in dosage, formulation, brand, frequency. Plus, while the length of the studies vary, they’re most often carried out over weeks or months, Dr. Knoedler says. Not exactly instant.
Certain vitamin and mineral supplements can absolutely be beneficial to correct deficiencies caused by malnutrition, a health condition, or aging, Kaplan says. In that case, supplements can bring them back up to the baseline that their immune system needs to function properly. But for someone getting enough of these micronutrients—which most of us eating a reasonably healthy diet are, says Van Oers—there’s not solid evidence for an “extra boost.” Generally speaking, “If you’re not deficient, then adding more above the normal level doesn’t make your immune response any better,” Kaplan says. (There are also health risks given the potential interactions or side effects. Talk to your doctor if you’re thinking of taking something.)
The best ways to support your immune health
“Given that there are so many components and intricacies of the immune system, we just want to help it work as a whole like it’s supposed to,” Dr. Knoedler says. That means providing some basic but important support to keep the whole system running smoothly.
While there aren’t any magical pills or foods here, there are some general principles and basic healthy habits that have been shown to support a well-functioning immune system over the long term, Dr. Knoedler says. That means eating well, sleeping seven to nine hours every night, getting moderate exercise, and managing your stress levels, Dr. Knoedler says. You’ll notice these are the same habits recommended to support most facets of good health.
Importantly, all of these behaviors are cumulative and should be long-term, consistent habits, Van Oers says. Take your diet, for instance. When we talk about diet supporting a healthy immune system, it’s not about pounding celery juice for a few days in a row to “boost” your immunity (or, on the contrary, trashing your immune system after three slices of cake). “Generally, these are long-term dietary changes,” Van Oers says. Eating a varied and nutritionally rich diet consistently supports your immune system over the long term in several ways, including helping you maintain the proper balance of the vitamins and minerals as well as the microbiota (good bacteria in your gut) that your immune system needs to function properly, Van Oers says.
So as enticing as the idea of giving your immune system an instant glow-up might be, the truth is that—as with so many aspects of your health—slow and steady wins the race. “There’s no overnight fix,” Van Oers says.