The most popular piece in the New York Times today is an Op-Ed published on Monday by Jennifer Ackerman, “How Not to Fight Colds.” It’s an interesting piece and points out something that a lot of people probably don’t know—it’s the immune system, not the virus itself, that causes the cold’s nasty symptoms. But in my opinion, Ackerman takes her assertions a little too far, in the process confusing multiple aspects of the immune response. While it’s probably true that certain immune responses worsen symptoms once a cold infection has been established, Ackerman also implies that a strong immune system does not help the body stave off infections in the first place. And based on the scientific evidence I’ve been able to find, I don’t think that’s a fair conclusion.
The immune system is a machine made of many parts. When a virus attempts to invade the body, the innate immune response, a non-specific system that basically throws darts at the intruder, is the first thing that ramps up. If the virus nevertheless manages to set up shop, the adaptive immune response kicks in, which among other things produces the inflammatory molecules that cause cold symptoms as well as the antibodies that protect you against the same cold in the future. So the immune response that initially fights the invading virus isn’t the same one that kicks in once the infection has established its roots. It stands to reason, then, that while some aspects of immunity (particularly adaptive immunity) may well worsen symptoms, other aspects of immunity may not, and may in fact be very important in protecting against infection. Yet Ackerman writes:
In any case, the supplements, remedies and cereals that claim to strengthen immunity (and thereby protect you from colds) do no such thing. It would be one thing if by some magic they made your body produce antibodies to any particular virus. But they don’t. And though some of these products contain ingredients that have been shown in studies to affect elements of the immune system, there’s scant evidence that they bolster protection against infection by cold viruses. No one knows which immune agents — other than antibodies — accomplish that.
Ackerman argues that antibodies are the body’s only known defense against colds. This would be surprising, given that antibodies are but one tiny part of the immune response to most pathogens; it’s also not backed up by existing evidence. An antiviral protein known as viperin is now thought to play a role in fighting cold infection, for one: a 2008 study published in Respiratory and Critical Care Medicine reported that when viperin activity is stifled during cold infections, the virus replicates more quickly. A 2004 study published in the Journal of Immunology suggests that a protein called human -defensin (HBD)-2 plays a role in host defense against the cold virus, too.
Granted, there is still much left to be learned about how viperin and human -defensin (HBD)-2 affect host protection, and they may not even be the most important players. But the point is, immune proteins other than antibodies do seem to help fight infection—they help to make you better, and perhaps even stave off infection from the getgo. So while Ackerman may be right that ramping up certain aspects of immunity with supplements and vitamins might make you feel more miserable once you have a cold, a robust immune system may not a bad thing when it comes to preventing and fighting the nasty bugs. If it were, then the best defense against a cold would be to stay up all night drinking and then attempt to run a marathon—because that’s a surefire way to pull the body’s resources away from immunity. I don’t know about you, but to me, that really doesn’t seem like a good idea.
Proud, D., Turner, R., Winther, B., Wiehler, S., Tiesman, J., Reichling, T., Juhlin, K., Fulmer, A., Ho, B., Walanski, A., Poore, C., Mizoguchi, H., Jump, L., Moore, M., Zukowski, C., & Clymer, J. (2008). Gene Expression Profiles during In Vivo Human Rhinovirus Infection: Insights into the Host Response American Journal of Respiratory and Critical Care Medicine, 178 (9), 962-968 DOI: 10.1164/rccm.200805-670OC
Proud D, Sanders SP, & Wiehler S (2004). Human rhinovirus infection induces airway epithelial cell production of human beta-defensin 2 both in vitro and in vivo. Journal of immunology (Baltimore, Md. : 1950), 172 (7), 4637-45 PMID: 15034083
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