| MadSci Network: General Biology |
Aloha, Autumn,
My apologies for taking so long in answering this question. During
summer, I'm not always in my office. Also, I needed some help in
answering this question, since it has several pieces to it, as you will
see. Dr. Alan Titchenal, who also teaches introductory nutrition with me,
helped me think through some of the answer. First off, I'm not sure if
you meant to ask about 'melanin' or 'melatonin'...so I will discuss both.
According to my medical dictionary, melanin is the dark pigment of
the hair, skin, the covering of the eye, and a part of the brain
(substantia nigra..'nigra' meaning 'black'). Melanin can also be found in
some tumors (like dark moles on the skin). It is made in the body from a
portion of protein (the amino acid tyrosine)...so for your body to make
the correct amount of melanin, you simply need to have adequate protein in
your diet. Fruits contain very little protein. Good sources of protein
include meat, fish, milk/milk products, eggs. Protein is also found in
varying amounts in grain food(bread, pasta, rice, noodles, etc.). Your
body is programmed via your genes (your inheritance from your biologic
parents) to produce a certain amount of melanin...that is why we all have
different colors to our skin. People who have darker skin simply have
more melanin produced in their skins that do people with lighter
skins...and melanin does offer some protection from the damage that
certain UV-wave lenghts in sunlight can cause. Thus a darker-skinned
person has more sun-protection than a fairer-skinned person. As an aside,
I don't think you can regulate the amount of melanin that your body
produces...unless you modify your genetic make-up somehow...and
scientifically we aren't there yet.
The reason that I think you might have meant 'melatonin' is that it
sounds like 'melanin'..and melatonin is in the news a bit, related to its
use as a sleep-aid supplement. Melatonin is also made in your body from a
piece of protein (the amino acid tryptophan). Most of the melatonin in
your body is found in the pineal gland, which is in the upper part of the
brain, just under the skull. Melatonin is a hormone that plays a role in
sleep regulation...and people have used melatonin supplements to modify
their sleep-wake cycles, with varying degrees of success/failure. There
is an excellent website about sleep/melatonin (www.sleepfoundation.org)if
you're interested. There is only one direct food source of melatonin that
I've been able to find: tart cherries. I have no idea why it is found in
cherries?!
The melatonin in supplements is extracted from BEEF pineal glands.
With all the current discussion about mad cow disease, I'm not sure if
taking these supplements is a wise choice, since the prion (disease-
causing particle) that seems to be the cause of a mad-cow-like disease in
humans (varient Creutzfeld-Jakob disease, vCJD) is found in the
brain/spinal cord of infected cattle. I don't think that eating beef
grown/raised in the US is a danger (yes, I eat beef, myself), since we
have had no cases of vCJD caused by any beef eaten here...and I don't
think we will. However, it has been a problem in England over the last
decade. Anyway, if you were interested in melatonin, rather than
melanin...there are a number of things to consider: the source of the
supplement, the reason for taking it, and the amoung that you would be
taking.
Melanin? Melatonin? Either one: they are made from portions of the
protein in your food. If you are getting enough of a variety of protein
foods, you are able to make plenty of either. Also, unless you take large
amounts (like melatonin) as supplements, you probably can't change the
amount of either in your body. Especially for melanin, since the amount
of that is tightly controlled by your genes.
Try the links in the MadSci Library for more information on General Biology.