Body Odor – An Unlikely Indicator of Genetic Suitability

• The cells of your body have surface markers that are unique to you. The markers are proteins that comprise what is called the Major Histocompatibility Complex (MHC), and the evidence indicates that the MHC influences both body odors and odor preferences in humans, and a woman’s preference depends on her hormonal state.

In a 1995 study, the MHC was determined for male and female participants. Each male wore a T-shirt for two consecutive nights. The shirts were then placed in a closed box with a “sniff hole” in the top. Each female student was asked to sniff and rate the odors of six shirts. The researchers discovered that women were more attracted to odors from shirts of men whose MHC was different from theirs. However, women taking birth control pills tended to select the shirts of men whose MHC was similar to theirs. The benefit from selecting a mate with a different MHC system provides gene mixing in offspring that may better protect them from diseases and parasites.

Rachel Herz and Elizabeth Cahill (experts on olfaction at the famous Monell Chemical Senses Center) said they would not be surprised to find that women attempt to sniff out a genetically proper mate, and that it may be the most important variable in choosing a lover. (Wedekind, et al, 1995, Proceedings of Biological Sciences, June; Chaix and Donnelly, 2008, PLos Genetics, Sept. 12; ASHI Quarterly, 3rd quarter, 2001)

• “Normally, male cardinals with the brightest red feathers are also the most fit, because they’ve competed successfully for foods that contain the carotenoid pigments that produce red—which happen to be the most nutritious foods.” The color of the plumage of many birds is influenced by diet. For example, pink flamingoes derive their color from their diet of crustaceans and algae that contain carotenoid pigments. (National Wildlife Magazine, Feb./March, 2013; other sources)

• Korean researchers examined the genealogies of boys castrated to serve in the palace of the Chosun Dynasty between the 13th and 20th centuries. They discovered that the castrated males lived up to 19 years longer than their peers and were 130 times more likely to reach the age of 100 than males living in the developed countries of today. As males age, testosterone may weaken the immune system and increase the risk of cardiovascular disease—thus in its absence males tend to live longer. (The Week, Jan. 4, 2013)

• Acetylcholine is a major neurotransmitter in the brain. A number of common drugs appear to have anticholinergic properties, which means they interfere with this transmitter, resulting in diminished cognition. Some drugs that definitely affect acetylcholine include Elavil, Dimetapp, Flexeril, Dramamine, Benadryl, and Paxil. Drugs that possibly interfere with acetylcholine are Atenolol, Wellbutrin, Valium, Luvox, Zantac, and Coumadin. And there are others. (Boustani, et al, 2009, Aging Health, p. 311-320; Campbell, et al, 2009, Clinical Intervention in Aging, 225-233; see list of drugs at http://www.indydiscoverynetwork.org)