Skin tone is relative to the amount of melanin in the body. While this pigment does provide a modicum of protection for individuals with brown skin, skin cancer may be much more severe when it does develop in this population.
Researchers at the M.I.T. in Cambridge, Massachusetts have found that when melanoma cells are deprived of leucine, it may be lethal to these cancerous cells.
Leucine is among the nine essential amino acids that humans do not synthesize naturally, but must ingest through diet. Amino acids are the building blocks of proteins used in all cellular functions. Nutrients such as amino acids are regulated by the mammalian target of rapamycin (mTOR) pathway. When there is a low level of an amino acids, this pathway is turned off, which initiates the autophagy process.
Autophagy functions to elevate the amino acid levels by the break down of protein into its smaller constituents. However, in the absence of leucine, autophagy is not activated in melonoma cells. A nutrient shortage is registered, which results in cell death. This holds promise for therapeutic remedies.
While more melanin adds one layer of protection against the sun, compared to individuals with less pigment, the use of sunscreen for dark skinned individuals cannot be overemphasized. Dr. Susan Taylor, African American dermatologist, recommends a minimum of SPF 15 for everyday use.