Have you ever wondered why some people never seem to get the flu when it is going around? Turns out that our genes play a role in both our immune response to the flu virus and the virus’ ability to replicate in us.
Simply put, some people are just more susceptible to getting the flu than others.
This year’s main flu strain going around is an H3N2 strain, while the flu vaccine that everyone was encouraged to get is more effective for an H1N1 strain. The CDC’s interactive map shows that the flu is now widespread throughout the continental US.
Genetic variants affecting susceptibility to H3N2:
A 2016 study looked at genetic variants in some of the genes involved in immune response. It found that variants in IL17 (interleukin-17), IL28 (interleukin-28), and IL1B (interleukin-1 Beta) increased the risk of getting the flu. Keep in mind that even if you are at half the normal risk, you can still get the flu if you are exposed to it, especially if you have a compromised immune system.
- GG: normal risk for H3N2 flu (compared to AA)
- AG: normal risk for H3N2 flu (compared to AA)
- AA: ~ half the risk for H3N1 flu
- AA: normal risk for H3N2 flu
- AG: normal risk for H3N2 flu
- GG: less than half the risk for H3N2 flu
- TT: normal risk for H3N2 flu
- GT: ~ half the risk for H3N2 flu
- GG: ~ half the risk for H3N2 flu
If you are interested in other studies on these genes, check out snpedia.com for links to a lot of research showing the different risks associated with the genetic variants. Take for example rs2275913 (IL17A), for which the AA genotype decreases the risk of the flu. Studies have shown that the AA genotype for rs2275913 increases the risk of gastric cancer, asthma, and rheumatoid arthritis, but is protective against stroke (and the flu).
This is yet another reminder that genetic variants that have survived in a population that give greater susceptibility to something bad usually are protective against something else. A popular naturopathic doctor, Dr. Lynch, has a new book out called Dirty Genes and seminars on how to clean up your genes. The title of the book really irritates me; perhaps I’m just an optimist at heart. Instead of labeling genetic variants as ‘bad’, realize that our ancestors who survived a famine, a disease, or in a specific environment passed down the genes because they were beneficial. Even disease gene mutations, such as those causing Cystic Fibrosis, give an advantage to those who carry only one copy of the mutation and are thus less likely to die from cholera.
More to read:
The Cochrane Review of Tamiflu (oseltamivir) shows that adults have an average flu duration of 7 days without Tamiflu and 6.3 days with Tamiflu. The study concludes, “Oseltamivir and zanamivir have small, non-specific effects on reducing the time to alleviation of influenza symptoms in adults, but not in asthmatic children.” Read through the study for yourself. To me, the risk of side effects from Tamiflu doesn’t seem worth it for a half-day reduction in flu symptoms, but I might make a different decision if I had the flu right now.
Diet and Lifestyle Actions:
The CDC recommendations include staying away from people who have the flu and washing your hands often. Seems like common sense.
Looking for natural products to prevent the flu? A study (in rats) found cinnamon essential oil to decrease flu virulence and deaths. Cinnamon essential oil is often found in oil blends marketed to prevent illnesses such as DoTerra’s On Guard, which is available on Amazon if you don’t have a friend trying to sell it to you, or Young Living’s Thieves oil, also on Amazon. There is also an in vitro study using On Guard that shows that it might help against the flu.