'Just as food is consumed and digested by the body, pornography is consumed by the senses and digested by the brain. In the digestive process, food is broken down so that it can supply the body with energy. Waste products are excreted to ensure the health of the organism. Similarly, pornography is taken into the brain via our senses primarily through sight and touch. However, there is no process for the "waste" products associated with pornography to be removed. Pornography and our response to it alter our brain in a way that is difficult to undo. Pornography is the consumption of sexual poison that becomes part of the fabric of the mind.'
William M Struthers, Wired for Intimacy: How pornography hijacks the male brain, p.20.