by Michael Colgan, Ph.D.

Skin is our biggest organ. It is exquisitely sensitive to everything we eat, breathe in, and slap onto it. Skin grows outwards continuously from deep inside. Your whole skin surface flakes off and replaces itself about every 28 days. We slough off about 40,000 dead skin cells every hour. The cloud of flakes surrounds us continuously like the cartoon of Pigpen in Charlie Brown.

All aging of skin occurs in the developing skin cells deep below the surface. The surface layer, the epidermis, is composed of dead and dying cells from underneath. All the aging has already occurred in surface cells. Unhappily, when they rise to the surface, they show the aging as wrinkles and lines and changes of color and tone. Ultra-violet light easily penetrates skin down to the developing cells and damages them, especially in the thin skin of the face. Face creams incorporating broad-spectrum ultra-violet blocking minerals are very effective. In the latest study, just published in the Annals of Internal Medicine, women using a daily UV blocking cream showed zero photo-damage after more than four years of measurement (1).

In misguided efforts to go green and save energy, we have now introduced lights into our indoor environment that are as damaging as sunlight. Fluorescent lighting has always given off some ultra-violet (that’s why it looks bluish), but was considered safe. The newer compact fluorescent bulbs, however, now used widely in homes and commercial buildings, are known to cause considerable photo-damage to human skin cells (2). Until government becomes smart enough to remove this health hazard, you can protect yourself by using a broad-spectrum UV blocker every day, whether going out into the sun or not.

Protection against skin aging is much more than avoiding photo-damage. It is at least a three-fold strategy. First is the cosmetic strategy to maintain the skin surface and guard against photo-damage. Second is the strategy to get protective nutrients into the developing skin cells in the deep dermal layer. By far the best way to get active nutrients into the dermal layer is by incorporating them into the diet. That way they enter the blood circulation, including the circulation of blood throughout the skin, from which the developing skin cells take their nutrients.

The combination of cosmetics and oral supplements of nutrients that are active in the skin is now the subject of intense research in dermatology (3). I will note five of the best that are supported by recent controlled trials. I have room to cite only a tiny few of the studies. They are some of the same nutrients that yield anti-aging benefits to our most important organ, the human brain (4).

Free radicals from toxins in the air and in the blood are a major source of skin aging. Epigallocatechin gallate (EGCG) from green tea reduces free radical harm to human skin cells (5). Acetyl-L-carnitine improves nerve regeneration in skin, an important benefit in skin injury, and in the loss of skin nerves with aging (6). R+ lipoic acid reduces cell death in skin and mucous membrane cells (7). Carnosine reduces glycation, the crosslinking of proteins into inelastic clumps, a major source of development of wrinkles and lines (8,9). We use these nutrients every day.

The third strategy for youthful skin is sleep. It really is “beauty sleep”. Directed by your circadian rhythm, the body cools in anticipation of bed time by about half a degree. To do so, the circulatory system increases blood flow to the skin for cooling. This is why the cheeks often flush at night.

The increased blood flow also causes the skin to perspire. This moisture fills all layers of the skin and smoothes out wrinkles. It is a natural moisturizer, the best there is, and is applied to the skin during sleep when it is most relaxed, and most repairable.

Serum growth hormone also surges during sleep. Combined with increased blood flow to the skin, growth hormone has two main effects. First, it causes a large increase in skin regeneration, which peaks at about 2:00 am. Second, it supports the recovery of the skin collagen matrix (10).

Our melatonin rhythm during sleep controls skin renewal. As we age beyond 25, melatonin levels decline sharply. Low melatonin level is a major reason why good sleep is harder to get as we age. The right melatonin supplement fixes the sleep problem for many folk, with a big bonus of also maintaining their skin. Melatonin is so effective in increasing skin growth and preventing free radical damage to skin, it is now being given to burn victims to promote healing (11).

There are also direct measurements of sleep and skin aging. New double-blind research presented by Elma Baron, M.D., at the 2013 International Dermatology Convention in Edinburgh, Scotland, compared a group of women, ages 30 to 49 who sleep well, with a group of the same ages who sleep poorly. The researchers found rapid skin aging in the poor sleepers. Dr. Baron stated, “Our study is the first to conclusively demonstrate that inadequate sleep is correlated with reduced skin health and accelerated skin aging”.

As I have explained elsewhere, eating dinner late is an all-round NO-NO if you want to prevent aging, as it disrupts sleep and both melatonin and growth hormone rhythms. Sleep empty. Sleep dark to promote melatonin release. Sleep cool to enhance blood flow to the skin and its need to perspire. Sleep on your back to avoid creating irreversible wrinkles (12). Sweet skin dreams.


  1. Hughes MC, et al. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med. 2013 Jun 4;158(11):781-90. doi: 10.7326/0003-4819-158-11-201306040-00002.
  2. Mironava T, et al. The effects of UV emission from compact fluorescent light exposure on human dermal fibroblasts and keratinocytes in vitro. Photochem Photobiol. 2012 Nov-Dec;88(6):1497-506. doi: 10.1111/j.1751-1097.2012.01192.x.
  3. Draelos ZD. Cosmetics, diet, and the future. Dermatol Ther. 2012 May-Jun;25(3):267-72. doi: 10.1111/j.1529-8019.2012.01500.x.
  4. Colgan M. Save Your Brain. Vancouver: Science Books 2008.
  5. Feng B, et al. Effect and mechanism of epigallocatechin-3-gallate (EGCG). against the hydrogen peroxide-induced oxidative damage in human dermal fibroblasts. J Cosmet Sci. 2013 Jan-Feb;64(1):35-44.
  6. Wilson AD, et al. Acetyl-l-carnitine increases nerve regeneration and target organ reinnervation – a morphological study. J Plast Reconstr Aesthet Surg. 2010 Jul;63(7):1186-95. doi: 10.1016/j.bjps.2009.05.039.
  7. Artwohl M, et al. R-(+)-alpha-lipoic acid inhibits endothelial cell apoptosis and proliferation: involvement of Akt and retinoblastoma protein/E2F-1. Am J Physiol Endocrinol Metab. 2007 Sep;293(3):E681-9.
  8. Babizhayev MA, et al. Skin beautification with oral non-hydrolized versions of carnosine and carcinine: J Dermatolog Treat. 2012 Oct;23(5):345-84. doi: 10.3109/09546634.2010.521812.
  9. Bellia F, et al. Neuroprotective features of carnosine in oxidative driven diseases. Mol Aspects Med. 2011 Aug;32(4-6):258-66. doi: 10.1016/j.mam.2011.10.009.
  10. Morris CJ, et al. Circadian system, sleep and endocrinology. Mol Cell Endocrinol. 2012 Feb 5;349(1):91-104. doi: 10.1016/j.mce.2011.09.003.
  11. Maldonado MD, et al. Melatonin as pharmacologic support in burn patients: a proposed solution to thermal injury-related lymphocytopenia and oxidative damage. Crit Care Med. 2007 Apr;35(4):1177-85.
  12. Jaliman D. Skin Rules. New York: St Martins Press, 2012.