While no new ‘silver bullet’ for immune health has come on the scene since the start of the pandemic, many trusted ingredients have seen increased interest and sales. In some cases this interest has been aroused by data coming out of the treatment of COVID-19 suffers, while in other cases it is based on research dating back some years.
The big winners in the immune support game have been elderberry products, which are addressed in a separate article. But other longstanding ingredients have seen sharply rising sales and interest in their scientific backing, which in some cases has extended even to calls for official recognition of health effects.
One outstanding example is the story of vitamin D. This prohormone substance has long been studied for its many health benefits that extend far beyond the old ‘strong bones and teeth’ story. After a method to measure 25(OH)D levels in the blood became available, researchers started to find wide ranging health effects for the vitamin.
For example, a study published in the journal Nutrition in 2017 found an association with low vitamin D levels and lower levels of HDL-cholesterol and a higher ration of total cholesterol to HDL, both markers of higher cardiovascular disease risk. A large scale population study published in the next year presaged the current fevered interest in the vitamin when it found insufficiency linked to respiratory health problems.
But it was the start of the pandemic in the West in 2020 that saw research interest in the vitamin truly soar. As researchers around the world started to sort through the mountains of data coming out of the pandemic, some stunning associations started to become clear.
For example, researchers at the University of Chicago, routinely ranked as one of the world’s leading academic institutions, said in September of last year that their retrospective study indicated that patients low vitamin D levels were almost twice as likely to test positive for a COVID-19 infection as were their peers with higher levels. A review published last year in the journal Nutrients found an “indisputable relation between vitamin D and the immune system.”
The research frenzy surrounding the vitamin culminated with an official recognition of sorts of its health effects and importance in the current crisis. In a highly unusual move, recently US Rep. Glenn Grothman (R-WI) introduced a resolution to recognize vitamin D’s immune health importance in light of the pandemic crisis. Grothman cited recent research (including the Chicago study) as well as an open letter from researchers sent to 120 world governments about vitamin D and immune health.
Vitamin C has long been thought if as the go-to ingredient during cold and flu season. Past research on the ingredient has been mixed. For example, a Cochrane Review paper on the subject found that vitamin C lowered the risk of respiratory infection by more than 50% for a mixed cadre of marathon runners, skiers and solders on Arctic exercises, but did not state that equated to protection for the average individual.
A review conducted this year by Finnish and Australian researchers that looked through COVID-19 data found that in 12 trials with 1,766 patients vitamin C supplementation reduced the length of ICU stay on average by 7.8%. In six trials, orally administered vitamin C in doses of 1–3 grams per day (g/day) (weighted mean 2.0 g/day) reduced the length of ICU stay by 8.6%.
In an interesting twist, a study published late last year found genetic differences in how individuals utilize vitamin C. The levels of a specific cellular transporter might determine whether the vitamin is useful in helping patients better weather a bout of COVID-19.
This mineral is another longtime immune health mainstay that has seen increased interest in the past 12 months. The potential immune health benefits of zinc are linked to “strong support” for treating the upper respiratory infections, notably the common cold, due to its anti-viral activity, said Prof Neil Walsh of Liverpool John Moores University, in the UK.
A 2017 meta-analysis published in the Royal Society of Medicine’s JRSM Open found that zinc lozenges providing 75 mg per day of elemental zinc may shorten the duration of the common cold by about 33%, but the zinc must be taken within 24 hours of the onset of the infection.
While the mineral has not been linked to distinct COVID-19 outcomes as has vitamin D, it still stands to benefit in the sales department. Retailer Natural Grocers predicted in a report earlier this year that sales of vitamin D, C and zinc all will rise this year.
Probiotics product marketers often cite the notion that much of the human immune system resides in the gut. And indeed, a recent study supports the notion that a probiotic can boost the immune system as judged by the changes in various biomarkers. The study, conducted with a proprietary strain of Bacillus subtilis found the probiotic supported a robust immune response based in part on the participants’ response to stimulation with bacterial lipopolysaccharide.
But data specific to COVID-19 outcomes has been scarcer than for some of the other ingredients, partly because probiotics, even with their long history, still have less presence in the marketplace than do the multivitamin ingredients. So fewer patients diagnosed with a COVID-19 infection would have had a probiotic in their systems, and few health professionals would likely be specifically asking after that information when checking in patients.
Nevertheless, a preliminary study from Mexico supports the notion that using a probiotic composed of proprietary L. plantarum and P. acidilacti strains lessened the duration of symptoms for COVID-19 sufferers who were not hospitalized.
Even with the relative dearth of scientific data as compared to other immune health ingredients, probiotics have benefited greatly from heightened consumer interest in any ingredients that might boost immune health. A report from Lumina Intelligence that went out earlier this month showed that online engagement with probiotics product listings rose more in 2020 than it ever has.