(Authors: Dr. Sanjay Kapur and Margaret Groves)
Skin health is a major concern, especially in ageing women, which is very good news for the cosmetic and anti-ageing industry. It is no coincidence that the decline in hormone levels as people age parallels the decline in skin properties frequently associated with ageing. A major culprit for the skin thinning, wrinkling, and dryness associated with ageing is the decline in hormones such as estrogen and progesterone in women, and testosterone in men. Hormones are intrinsically involved with processes affecting the maintenance of skin health, such as collagen content, skin lipid levels, elasticity, wound healing, glycoaminoglycan content, and facial hair patterns.
The skin is one of the main targets of estrogen action, and facial skin expresses much higher concentrations of estrogen receptors than the skin of the breast or the thigh. This means that the effects of declining estrogen levels as women progress through menopause are more obvious on the skin of the face than on the skin covering other parts of the body. Reduced availability of estrogen affects skin health in a number of ways: these include wrinkling, dryness, thinning, reduced collagen content, slower wound healing, and loss of elasticity.
Obese men and women often don’t show this deterioration in skin health to the same extent as normal weight people; this is because they maintain higher estrogen levels as a result of increased aromatase activity in fat and skin tissue. Aromatase is an enzyme that converts testosterone into estradiol and androstenedione into estrone, and it is present in large quantities in fat tissue. Estrone and estradiol are therefore found in larger amounts in obese individuals than in normal weight people of the same age. Estradiol is the most potent estrogen, and its main source is the ovaries in reproductive women. Estrone, with weaker estrogenic effects, becomes the more prominent estrogen produced in postmenopausal women as their ovaries stop estradiol production.
Studies of estrogen replacement therapy have shown some improvement in those skin properties affected by low estrogen levels, e.g. increased collagen content, skin thickness, and skin elasticity. Hormone replacement has also been found to increase skin surface lipids, which enhances the barrier function and may prevent dryness. Estrogen also plays a role in maintaining skin glycoaminoglycan content, which retains moisture.
Low testosterone in men is associated with thinning skin. This is thought to be because there is less testosterone available for local conversion to estrogen through the action of aromatase present in the skin. Testosterone replacement has been found to increase skin thickness.
Progesterone has been used in cosmetic skin creams as well as in hormone replacement therapy, and has been found to improve skin thickness and elasticity. Studies have indicated no adverse effects when progesterone is used for this purpose, although some women find that progesterone cream can result in skin breakouts, possibly as a result of other ingredients in the formulation.
Low progesterone levels are thought to increase the impact of androgens on sebaceous glands and body and head hair. This is because progesterone reduces 5-alpha reductase activity, which converts testosterone to its active metabolite dihydrotestosterone (DHT). DHT is the culprit for androgenic side effects in women such as unwanted facial hair growth, which tends to appear with ageing or in androgen excess conditions such as PCOS. In both men and women, excess DHT in the skin contributes to acne, and in the skin of the scalp it is responsible for “male pattern baldness”.
High levels of hormones can contribute to skin discoloration, e.g. the brown patches (“chloasma”) associated with pregnancy or with hormone replacement therapy.
Hormones are important for skin wellness, but caution should be exercised by women and men seeking to reverse skin deterioration by using hormone replacement. Hormonal deficiencies can be identified with minimally invasive laboratory testing and treated with hormone replacement to improve overall health and wellness as well as to mitigate the effects of ageing. However, hormone replacement should be done with appropriate monitoring to ensure that no higher than physiological hormone levels are achieved. It is important to understand that hormones have powerful effects throughout the body. While hormone replacement is not usually recommended solely for cosmetic purposes, proper monitoring of hormone levels in an ageing population can help identify deficiencies that can be resolved with judicious hormone use, which may have the added benefit of improving skin wellness and thereby saving substantial costs in cosmetic treatments.