Sunday, January 17, 2010
Hormesis and Egyptians
What do you think of when you hear the term 'hormesis?' Rick and I both learned this week in the journal Analytical Chemistry, admittedly a bit of a stretch for us, that hormesis refers to the property of something having a beneficial effect at one level but a deleterious one at another. And we learned this from a fascinating study: Finding Out Egyptian Gods’ Secret Using Analytical Chemistry: Biomedical Properties of Egyptian Black Makeup Revealed by Amperometry at Single Cells.
Turns out that kohl makeup, that black eyeliner used by ancient Egyptian men and women to outline their entire eye, has a medicinal property. It leaches at very low levels into the fluid that bathes the eye continuously, creating a very low level of inflammation. This inflammation in turn helps protect the eye from conjunctivitis due to infections the Egyptians were susceptible to following periodic flooding of the Nile river.
Wow. Who knew? And the ancients were even more sophisticated than that. These lead compounds used in their eye makeup were not naturally occurring. Instead they required fairly skilled chemistry to produce so that the lead level that leached from them was just right to elicit a helpful immune response. Another Egyptian wonder, right alongside the pyramids.
The study illustrates this term we're likely to hear more and more: hormesis. Rick says there are many examples of this in medicine today: low levels of many vitamins turn out to be helpful in some people, especially those who are vitamin deficient, while higher levels aren't at all helpful and may be harmful. Witness vitamin E supplementation in smokers.
Alcohol consumption is another great example. For many people a low daily consumption of alcohol seems to have a positive impact on health but the perils of overconsumption are well-known. Even exercise can be thought of 'hormetically' if such an adjective exists, where some or moderate exercise daily helps, but too much leads to overuse injuries and worse.
Other topics this week include whether chronic infections can cause in increased risk of stroke in this issue of Archives of Neurology, and a failure to treat chronic tendon problems and a mammography guideline update in this week's Journal of the American Medical Association. For a full discussion listen to our podcast: http://www.hopkinsmedicine.org/mediaII/Podcasts.html. Until next week, y'all live well.