Women can really 'sniff' out things better than men

Women are really superior to men when it comes to the sense of smell, says a new study.

Males and females greatly differ in their perceptual evaluation of odors, with women outperforming men on many kinds of smell tests. Sex differences in olfactory detection may play a role in differentiated social behaviors and may be connected to one's perception of smell, which has been naturally linked to associated experiences and emotions. Thus, women's olfactory superiority has been suggested to be cognitive or emotional, rather than perceptual.

Researchers at Federal University of Rio de Janeiro had developed a fast and reliable technique called the isotropic fractionator, that measures the absolute number of cells in a given brain structure such as the olfactory bulb, which is the first brain region to receive olfactory information captured by the nostrils.

Using the technique, a group of researchers led by Prof. Roberto Lent has finally found biological evidence in the brains of men and women that may explain the olfactory difference between genders.

The group examined post-mortem brains from seven men and 11 women who were all over the age of 55 at the time of death. All individuals were neurologically healthy and none worked in professions requiring exceptional olfactory abilities, such as coffee-tasting or professional cooking. By calculating the number of cells in the olfactory bulbs of these individuals, the group discovered that women have on average 43 percent more cells than men in this brain structure. Counting neurons specifically, the difference reached almost 50 percent more in women than men.

Prof. Lent said that generally speaking, since larger brains with larger numbers of neurons correlate with the functional complexity provided by these brains, it made sense to think that more neurons in the female olfactory bulbs would provide women with higher olfactory sensitivity.