Immunity-Boosting Supplements Won’t Protect You From Germs Returning to School
Ah, the fall. This is the season we send our kids to school with shiny new backpacks, and every year they bring home the same thing: the first series of colds at school. In our home, when a two-year-old sets out to drool over everyone he touches and a six-year-old is still perfecting his personal hygiene practices, pathogens spread like a hug, and it’s only a matter of time before the whole family is sick.
Unsurprisingly, back-to-school season also brings a splash of advice on how to boost kids’ immune systems while walking down the aisle with supplements. Health bloggers are sharing supplement regimens that they swear will keep their kids healthy during the winter. On my daughter’s open house in front of school, PTA handed out free samples of black elderberry extract gummies (a shape my kids find irresistible), claiming to be “delicious immune support for the whole family.” My toddler’s caregiver even asked if she could give him a mega dose of vitamin C to protect him from the inevitable outbreak of the common cold.
When I consider these supplement options, I start out with a grain of salt. The food supplement industry is poorly regulated and has a long history of safety concerns . The FDA does not test supplements for safety or effectiveness – or even test them to see if they contain what the label says – before they are placed on store shelves. It is usually only after receiving complaints of side effects that the FDA investigates the safety of the supplement, and they must prove that it is unsafe in order to remove it from the market. In other words, the use of supplements means the voluntary participation of ourselves and our children as participants in a poorly designed, uncontrolled study without a formal data collection plan.
As a parent, I am fresh in my recent memory of Hyland’s teething pills , which turned out to have erratic and sometimes toxic levels of belladonna (also known as “deadly nightshade”). The FDA received reports of hundreds of seizures and even deaths in infants after being given the pills, all because of a product that many parents swore and a company they trusted. (Hyland teething tablets have been classified as homeopathic remedies that are regulated slightly differently from supplements, but suffer from the same lack of control.)
Many supplements have studies, two or more, that show some beneficial effects, but it is important to take a close look at all available studies to learn about the study design, as well as the doses and drugs tested. For example, you will find many studies on the effects of echinacea and elderberry on isolated cells in test tubes or petri dishes, but we want to know if these drugs are safe and beneficial for the human body. And before I give the supplement to my children, I want to know that it has indeed been tested in children, because their small, not fully developed bodies can process it differently than adults .
Another factor to consider: Herbal and herbal supplements can contain many compounds with potential medicinal properties, and how they are extracted and prepared can vary greatly. To complicate matters further, companies often use proprietary blends that contain multiple ingredients, making it difficult to know if you’re buying anything close to what the research tested.
Vitamin and mineral supplements may seem simpler, but don’t assume that they are safe just because they are made from nutrients. Supplements often use doses much higher than what you can find in food, and this can have unintended consequences. Case in point: A study published last month in the Journal of Clinical Oncology found that men who took high doses of vitamins B6 and B12, which are often touted as energy-boosting vitamins, were nearly twice as likely to develop lung cancer.
Suffice it to say that I have a high bar of evidence that a supplement is beneficial and relatively safe before I consider giving it to my kids or taking it myself. But on the other hand, it would be great if I had less snot in my life this fall, so I took a look at a few supplements that claim to protect against colds.
Elderberry (and other parts of the European elderberry tree)
Let’s start with the elderberry marmalades because my kids are still waiting to hear if they can eat them. Several small human studies have looked at the effects of elderberry supplements on the flu and common cold, with some encouraging results that may shorten the duration of illness. However, this has been done on adults and I have not been able to find any data pertaining to children. (In a1995 study, 15 flu sufferers ranging in age from 5 to 50 years old took elderberry syrup, but this is a tiny sample size for starters, and the document does not detail how many of them were children.) From a safety standpoint, The National Institutes of the National Center for Complementary and Integrated Health (NCCIH) reports: “The leaves, stems, raw and unripe berries and other parts of elderberry plants contain a toxic substance and, if not cooked properly, can cause nausea and vomiting. and severe diarrhea. ” Sounds worse than a cold, so I’ll go through and get my kids gummy bears to catch up.
Echinacea
In a randomized controlled trial published in JAMA in 2003 , 524 children received either echinacea extract or a placebo when they felt an impending cold. There was no difference between groups for the duration or severity of cold symptoms, but children who took echinacea were more likely to develop rashes. The rash sometimes occurs with a viral infection, but because it is more common in the echinacea group (7.1 percent of children taking echinacea versus 2.4 percent of children taking placebo), the authors believe it may have been a reaction to the herb. A 2014 Cochrane review pooled results from previous studies – all in adults, with the exception of the 2003 study just mentioned – and also concluded that there was no evidence of benefits of echinacea for colds.
Garlic
Good Cochrane researchers have also studied garlic , but they only found one study that met their quality criteria. It was a randomized controlled trial, published in 2001 in the journal Advances in Natural Therapy , in which one group took a daily garlic supplement (equivalent to eating 10 cloves of garlic) and the other took a placebo for 12 weeks. The garlic group had far fewer colds, and when they did get sick, they suffered fewer days. The results seem promising, but here’s the thing: The study was conducted by one person who was also the director of a center called the Garlic Center in East Sussex, UK. In its coverage of the study, the BBC called him a “garlic enthusiast.” , ” And now he sells garlic supplements on the Internet. And while the document says it was a double-blind study, meaning that neither the participants nor the researcher needed to know who was taking garlic or a placebo, the smelly burp was noted as a common side effect in those who took garlic.
There are too many red flags here and no research has been done since then to try to reproduce the results. The Cochrane Review says there is not enough evidence to support the use of garlic for colds, and I agree.
Vitamin C
Vitamin C has been a popular cold remedy for decades, and as a child, my mom encouraged me to swallow large, sour-tasting pills when I felt the approach of a cold. Large doses of vitamin C are sold these days in tastier forms like Emergen-C and Airborne, but neither has shown much benefit. A 2013 Cochrane review pooled the results of 29 studies involving more than 11,000 people and concluded that taking vitamin C would not lower your chances of getting sick. The exception was hardcore people doing strenuous exercise; for marathon runners, skiers and soldiers training in subarctic conditions, taking vitamin C reduces their chances of getting a cold by about half.
Vitamin C appears to have a persistent but slight benefit in shortening the duration of cold symptoms. That translates to an 8 percent reduction in colds for adults and 14 percent for children – maybe one day less suffering. However, to see this benefit, you must take vitamin C every day, and often in fairly high doses. Some of the doses studied for children were above the Institute of Medicine’s upper limit, above which vitamin C can cause nausea, diarrhea, and abdominal cramps.
Zinc
Of all the supplements we’ve discussed, zinc lozenges may be the most promising for treating cold symptoms. They have been well studied in randomized controlled trials of adults, and several meta-analyzes consistently show that they shorten the duration of the common cold, especiallyif you are taking at least 75 milligrams per day , starting at the onset of symptoms. At this dose, the duration of the common cold in adults was reduced by 42 percent. Most zinc studies have been in adults, but a 2013 randomized controlled trial in Thailand found that children ages 8-13 who took a daily dose of zinc for three months had much shorter colds than those who took a placebo.
But then again, the doses of zinc used in these studies are much higher than what we usually get from food, and close to or above the recommended daily intake limit , so there may be some risk here. A Thai study in children involved taking high doses for months as a preventive measure, not just occasionally, which makes me even more wary. Nasal zinc has also been shown to cause loss of smell , so definitely avoid it.
After all, every supplement is a little gamble. Some promise benefits, but your results may differ, and most carry some risk of side effects. We need more elaborate research to clarify this trade-off, but in the meantime, my family will stick with washing their hands, coughing up elbows, getting enough sleep, and enjoying gummy bears without the added drugs.