Earwax, Odor, and Anxiety
Earwax, odor, and anxiety often go hand-in-hand. This post discusses the relationship between them.
Earwax and Body Odor
Earwax is the result of sweat glands, of which there are two types: eccrine and apocrine. Eccrine sweat glands are found throughout the skin (but not in the ear canal, although a few might be scattered over the pinna – the structure that we use to hold our eyeglasses in place) and produce sweat that is mostly water and salt. This contributes little to body odor.
Apocrine sweat glands are found in the armpits and groin, but have a modified form in the outer portion of the ear canal called ceruminous glands (ceruminous glands are modified apocrine glands). Sweat from apocrine glands contains proteins and lipids (fats). So, when bacteria on the skin metabolize apocrine sweat (digestion of apocrine sweat by bacteria), they produce body odor (Hyslop, 1971; Anonymous, 1972; Shugyo et. al., 1988; and Anderson and Meyerhoff, 1982).
Wet earwax is associated with greater body odor, even in populations where wet earwax is uncommon (Yoo et al., 2006). On the other hand, several of the precursors for body odor were absent or in lower concentrations in sweat from dry earwax genotypes (Martin et al., 2010).
This is consistent with a recent study by researchers from the Monell Center confirming that earwax is not the same between races. Some individuals have more odor-causing chemical compounds in their earwax than others. And, just as their previous research has shown that underarm odors can convey much information about an individual, including personal identity, gender, sexual orientation, and health status, Monell organic chemist researcher George Preti said:
“We think it possible that earwax may contain similar information.” “Odors in earwax may be able to tell us what a person has eaten and where they have been. Earwax is a neglected body secretion whose potential as an information source has yet to be explored.”
Researchers at Monell found that the number of volatile organic compounds (molecules that often produce a smell), is generally higher in Caucasians than in East Asians or Native American descendents. These groups possess a form of gene that makes them have dry-type earwax versus wet earwax.
Wet Earwax and Breast Cancer?
Interestingly, the ABCC11 gene studied for earwax is also associated with breast cancer. Apocrine glands are found both in the outer ear canal and in the breast. Earlier studies have been conflicting relating earwax and breast cancer (Ing and Petrakis, 1973; Petrakis, 1983). However, in 2009 Japanese scientists found that underarm odor and wet earwax could alert doctors to women who were carrying this gene and who have increased risk of breast cancer. Ishikawa (of the study) says they are cautious to say that having wet ear wax or excessively smelly armpits does not mean a woman is destined to get breast cancer. “To be clear, I should strongly mention that the [specific gene variation found to link body odor, wet ear wax, and breast cancer risk] is one factor that increases breast cancer risk.”
Earwax, Stress, and Hearing Aids
It has been reported that chemicals and hormones released when a person is afraid, fearful, anxious, under emotional stress, sexual excitement, manual stimulation (rubbing or cleaning of the ear canal) or an ear canal pain occurrence, could produce an increase in earwax, but the reasons are not clear (Perry, 1957). An increase in the production of cerumen holds true also for certain medications. Such natural and mechanical experiences are believed to cause an emptying of the cerumen glands. Extraction of cerumen is believed to result from stimulation of the sympathetic nervous system (SNS) during pain and stress.
Experience with hearing aid earpieces placed in the ear canal often show an increase in earwax. This seems to be especially true for individuals being new to having something placed into the ear canal. Speculation is that the ear canal is attempting to “protect” itself against a foreign invader by increasing its cerumen production.
Future articles on earwax will describe the mechanism, consequences, and treatment of earwax.
Anderson RG, Meyerhoff WL. (1982). Otologic manifestations of ageing. Otolaryngol. Clin North Am 15:353-370.
Anonymous. (1972). Wax in the ear. BMJ, 4(5841):pp 623-624.
Hyslop NE. (1971). Earwax and host defense. N Engl J Med 284:1099-1100.
Ing R, Petrakis NL, Ho HC. (1973). Evidence against an association between wet cerumen and breast cancer. Lancet;i:41.
Perry, ET. (1957). The Human Ear Canal. Springfield, IL, Charles C. Thomas.
Petrakis NL. (1983). Cerumen phenotype and epithelial dysplasia in nipple aspirates of breast fluid. Am J Phys Anthropol;62:115-18
Shugyo Y, Sudo N, Kanai K, Yamashita T Kumazawa T, Kanamura S. (1988). Morphological differences between secretory cells of wet and dry types of human ceruminous glands. Am J Anat, April;181(4):377-384.
feature image from Wikipedia