One Thing Short and Tall Men Have in Common

This article was originally posted on RealClearScience.

There aren’t very many things that short and tall men have in common. Tall men make more money, have a greater choice in women, and are likelier to be elected president than their vertically challenged brethren. For all the talk of “white privilege,” maybe it is time for our culture to ponder the implications of “tall privilege.” That’s because, as a general rule, short guys have received the short end of the societal stick. (No pun intended.)

But, in at least one biological aspect, short and tall men share something in common: A less than ideal immune response.

A team composed of European researchers examined how 130 young Latvian men (aged 19-30) and 65 young Latvian women (aged 18-24) responded to a hepatitis B vaccine. Specifically, they measured how much anti-hepatitis B antibody each person produced. Their results were reported in the journal Scientific Reports. (The graph below shows the data for men.)

As shown in the graph, the male antibody response was strongest when a man was 185 cm tall (roughly 6′ 1″), but was weaker for both shorter and taller men. No such relationship existed in women.

It is not entirely clear why this should be the case. The authors hypothesize that a larger body is costly in terms of resources, and thus, tall men have fewer resources to dedicate to maintaining a robust immune response. That is an interesting idea, but it does not explain why short men have a weaker immune response, and it also does not account for the lack of a relationship between height and immune response in women.

The study is further limited by their sample selection. It is possible, due to some genetic quirk, that the discovery applies only to people of Latvian or eastern European descent. The team also only examined young people, and their sample of women was half the size of their sample of men. It is possible that a larger study of women would yield a statistically significant result. Finally, the authors only examined a tiny sliver of the immune response, i.e.., the production of anti-hepatitis B antibodies. A more holistic approach — for instance, one that examines each person’s susceptibility to infectious disease — is desirable, but would likely require a large epidemiological study.

Though the team’s observation is certainly interesting, a lot more work needs to be done to establish a definitive link between human height and immune response.

Source: Indrikis A. Krams, Ilona Skrinda, Sanita Kecko, Fhionna R. Moore, Tatjana Krama, Ants Kaasik, Laila Meija, Vilnis Lietuvietis & Markus J. Rantala. “Body height affects the strength of immune response in young men, but not young women.” Scientific Reports 4, Article number: 6223. Published: 28-August-2014. doi:10.1038/srep06223