Sleep is a rejuvenating time for the body, mind, and spirit. It is a necessary part of the daily cycle of living. If a person is deprived of adequate sleep time – seven to eight hours nightly – they risk additional stress and premature aging, which is reflected in the skin's appearance.
Restoration and Renewal
Scientific evidence supports the connection between sleep and skin aging. While the body is at rest and asleep, many of the processes that go about repairing the damage of the day are set in motion.
While asleep, the body's nervous system switches to a parasympathetic state, which creates increased circulation and oxygen flow to the skin. Because of this increased blood and oxygen flow, internal repair and production activity in the skin is heightened. During certain cycles of sleep, skin cell regeneration almost doubles. This renewal is very important in replacing the epidermal protein sloughed off during the day due to normal exfoliation. It is necessary to keeping the skin from thinning and to maintaining a youthful glow.
The breakdown of collagen and hyaluronic acid in the extracellular matrix of the skin, which often occurs during the day, is replenished during sleep, when replacement production happens at a higher level. Increased collagen and hyaluronic acid production helps to keep wrinkles away and keeps the skin firmer and better hydrated.
While sleeping, the body's hydration rebalances. Because of all the regenerative activity in the skin happening during sleep, the skin will lose about 25 percent more water overnight than it does during the day. Thus, the skin can become somewhat dehydrated during the night. Other contributing factors include the lack of rehydration that occurs during the day and the increased water requirement due to renewal activity during sleep.
When a person is removed from the environmental stresses of the day, the body works overtime to repair damage from the day's pollution, sun, and stress. For the skin, this reparation means quenching free radicals by means of antioxidant activity, removing toxins absorbed in the skin, and reducing inflammation that may have increased from the day's activities.
There are two key times when human growth hormone is secreted by the pituitary gland: right after heavy physical activity and during certain sleep cycles of the night. Human growth hormone is the master hormone in preventing aging. It stimulates all of the organs of the body toward renewal, including the skin. Since it is secreted during sleep, it is obvious that the repair and renewal process of the skin, in order to fight aging, will also be at its highest activity level.
Given all of this activity within the skin that occurs during sleep, it stands to reason that an anti-aging skin care regimen could capitalize on the natural objectives of the skin at the perfect time of the daily cycle of repair and renewal. Ideally, the best nighttime skin care product would be one that provides outstanding hydration by all possible means, a rich suite of antioxidants to assist with environmental damage of the day, effective and gentle exfoliation to assist in skin turnover, and growth-assisting peptides and amino acids that will help increase skin and collagen growth activity.