I have low adrenal function and low blood serum DHEA, take a daily supplement (as per my doctor's instructions). I am aware of the overuse of DHEA, it's a powerful hormone! The Life Extension Foundation offers a cream with DHEA & melatonin that has just enough of the 2 substances to help your skin, but not get into circulation.
Here's the LEF's take on skin aging -- I'd love to hear your take on their theories!
DHEA and Melatonin
The sleep hormone (melatonin) and the anti-stress hormone (DHEA) are both found in human skin. Both are converted to other entities with important jobs to do. DHEA is converted into estrogen- and androgen-type metabolites found only in skin (Labrie et al. 2000). Melatonin is synthesized in skin. In low concentrations it can stimulate cell growth. This type of on-site, organ-specific production of hormones is called intracrine biosynthesis . Intracrine biosynthesis allows different organs to manufacture the substances they need without flooding the entire body with growth factors.
Estrogen's skin-enhancing effects are well-known (Dunn et al. 1997; Shah et al. 2001). It provokes collagen and a moisture factor known as hyaluronic acid . Aging decreases both estrogen and collagen. Enzymes that convert DHEA to estrogen also decline. Not surprisingly, women who take synthetic estrogen have scientifically proven thicker skin. Women who take both estrogen and testosterone have really thick skin (48% thicker than women who don't take either hormone) (Brincat et al. 1983). DHEA is converted to both estrogen and testosterone, providing the benefits of both hormones.
Although the exact roles of DHEA and melatonin in human skin are still under scrutiny, researchers have identified several mechanisms through which these hormones protect against aging, maintain the health of skin, and affect how sunlight reacts with skin cells.
Skin is such a specialized organ that it has its own immune system. It has been proposed that faulty skin immunity affects the entire immune system. Sunlight can penetrate deep into skin and alter immunity directly, or it can cause changes in dermis and epidermis that provoke immune changes. Sunlight affects hormones. It decreases melatonin, norepinephrine, and acetylcholine, and increases cortisol, serotonin, GABA, and dopamine.
Studies show that both DHEA and melatonin are absorbed by skin when applied topically. A study from CHUL Research Center (in Canada) shows that the activity of DHEA applied topically is 85-90% greater than when taken orally (at least in rodents). No special carriers are needed to get DHEA and melatonin into skin. A properly formulated topical preparation of melatonin and DHEA will contain just enough hormone to benefit skin without providing enough to escape into circulation. It makes sense to apply the hormones directly to the skin if skin protection is the goal, since ingested hormones may end up everywhere but the skin (Labrie et al. 2000).
DHEA Saves Skin
DHEA has beneficial effects beyond its conversion to skin-friendly hormones. DHEA itself has powerful skin protective effects. A study in the Journal of Surgical Research demonstrates the extraordinary ability of topically applied DHEA to protect skin's delicate blood vessels. Researchers found that if DHEA was applied after a serious burn, the blood vessels underlying the burned area are protected (Araneo et al. 1995). Protecting the blood vessels saves the skin. Skin and blood vessels that would otherwise die and peel off can be saved by DHEA. No one knows for sure how DHEA saves skin this way, but its anti-inflammatory action no doubt has something to do with it. DHEA prevents destructive white blood cells and their biochemical cousins from gearing up. In particular, DHEA affects a blood vessel killer known as "tumor necrosis factor."
DHEA has action against everyday insults as well. By maintaining skin immunity, DHEA preserves the ability of skin to react to cancer-causing, skin-destroying pollutants in air, food, and water. DHEA also has antioxidant action against peroxyl and superoxide free radicals.
Free radical defense may have a lot to do with DHEA's ability to prevent skin cancer and papillomas (benign tumors). According to several studies in mice, topically applied DHEA keeps oxidant-loving enzymes at bay. Chemicals with carcinogenic potential depend on oxidases for transformation. DHEA's antioxidant action stops them (Schwartz et al. 1986a; Schwartz et al. 1986b; Hastings et al. 1988). DHEA has another important defense: It keeps chemical carcinogens from binding to DNA (Pashko et al. 1985; Pashko et al. 1991).
Melatonin is an antioxidant hormone that protects against UV radiation (Fischer et al. 1999). A group at the University of Zurich has shown that topical melatonin gives excellent protection against sunburn if applied before sun exposure (Bangha et al. 1997). Melatonin also appears to have a role in repairing burned skin. In a study in Brain Research Bulletin , melatonin levels rose 6 hours after burn injury, then fell to normal (Scott et al. 1986).
In small amounts, melatonin causes skin cells to proliferate. (In large amounts, it stops proliferation.) People with psoriasis and atopic eczema do not have normal melatonin secretion. Instead of peaks, they have valleys. With psoriasis, melatonin peaks in the day when it shouldn't, and patients have little at night. It is surprising that a hormone connected to sleep has a lot to do with skin health, but maybe not to those researchers who consider the pineal gland another endocrine gland. Melatonin is secreted by the pineal gland.
I look forward to hearing your take on this! Thaks so much -- can't wait to get my shipment -- (*Hoo-Hoo-Hoo-Ha-Ha-Ha* -- the mad scientist emerges,... )
P.S. I'm the one in cow country, Ohio --