The liver requires all the energy it can get to fulfill these and many other responsibilities. This can only happen sufficiently, though, if you sleep during this time period. If you use up the nighttime energy for eating or for mental and physical activities, the liver is left with too little energy to do its extremely vital work. The kidneys also need energy during this time period to filter the blood  plasma, and keep the body fluids balanced and blood pressure normal.

Although the brain makes up merely 2% of our body mass, it normally contains more than 25% of the body’s entire blood supply. However, during this phase of the night, most of the blood located at the back of the brain moves into the liver for purification. If you are mentally or physically active at this time, the liver does not receive enough blood to work with, so it cannot cleanse the blood sufficiently. This results in the accumulation of toxic material in the blood stream. If toxins keep circulating in the blood, they will settle in the interstitial fluid (connective tissues) of organs and systems, thereby raising acidity and damaging them, including the liver itself. High blood toxicity can lead to secretions of stress hormones, brain fog, and injured capillaries, arteries and heart muscles. Most heart disease is the result of a poorly performing liver that is unable to remove all toxic, noxious substances from the blood on a daily basis. If we do not give the liver the energy it needs to conduct the most basic physiological activities, we sow the seeds of illness throughout the body.

Respiration is an important part of the cleansing and rejuvenation process, with a significant percentage of the body’s waste materials being eliminated through the lungs. This underscores the importance of sleeping in a room with ample ventilation.

Sleep can be divided into two main parts – before-midnight and after-midnight. For adults, the most important processes of purification and renewal occur during the two hours of sleep before midnight. This period involves deep sleep, often referred to as “beauty sleep.” It typically lasts for about an hour, from 11 pm to midnight. During this period, you enter a dreamless state of sleep where oxygen consumption in the body drops considerably. This results in profound physical rest and relaxation. The benefit to your body of this single hour of deep sleep is approximately equivalent to that derived during the three hours following midnight, when the oxygen consumption rises again.

Growth factors, commonly known as growth hormones, are secreted profusely during the hour of deep sleep. These powerful hormones are responsible for cellular growth, repair and rejuvenation. People age faster if they don’t produce enough growth hormones. The latest “fashion” in the beauty market is to consume synthetic growth hormones, which create remarkable rejuvenation results, but which also can have devastating side effects, including heart disease and cancer. On the other hand, if the body makes natural growth hormones at the right time and in the correct amounts, as happens during deep sleep, they can help keep the body vital and youthful.

Deep sleep virtually never occurs after midnight and it usually comes only if you go to sleep at least two hours before midnight. If you routinely miss out on deep sleep, your body and mind tend to become overtired. This triggers abnormal stress responses that initiate secretions of stress hormones such as adrenaline, cortisol or cholesterol (yes, cholesterol is a stress hormone that rises with stress!). Once the body’s energy reserves have been depleted, chronic fatigue results. Fatigue can be considered a major contributing factor in today’s health problems.

Doctors at the University of California at San Diego have found that losing a few hours of sleep not only makes you feel tired during the following day, but also can affect the immune system, possibly impairing the body’s ability to fight infection. Since immunity diminishes with tiredness, your body is unable to defend itself against bacteria, microbes and viruses, and cannot cope with the build-up of harmful substances in the body.