October 6th - 12th! 

S L E E P . . . 

• Memory Consolidation. Sleep is a time when the information and experiences we encounter throughout the day are processed and integrated into existing neural networks. Memories are created and strengthened. Sleep deprivation in general is associated with a decrease in working memory - this means we are less able to simultaneously hold different pieces of information in our heads, making complex thinking and multi-tasking more difficult. Loss of REM sleep in particular reduces procedural memory - the ability to perform actions like tying shoes or flying an airplane. Loss of non-REM sleep reduces declarative memory - the ability to recall facts and events. (1, 2, 3) 
• Tissue Repair and Regeneration. Sleep is an anabolic state in which tissues are “built up.” Wound healing is disrupted by sleep loss. Immune cell counts decrease, making us more susceptible to infection and cancer. Growth Hormone is released shortly after sleep onset, promoting tissue repair and growth. 
• Waste Removal. A fascinating 2013 study showed that lymphatic circulation in the brain increases during sleep, facilitating removal of metabolic wastes that build up during waking. Spaces between brain cells increased by 60% to promote clearance of particles such as amyloid beta, which is associated with Alzheimer’s disease. 

• Overall sympathetic ("fight or flight") response increased, while parasympathetic ("rest and digest") decreased. This means baseline stress levels were higher after several nights of insufficient sleep and digestive function may have been reduced. 
• Evening cortisol levels increased, possibly exacerbating insomnia, and growth hormone signaling was altered - both of these influence how our bodies respond to sugar and could promote diabetes long-term.
• Appetite-regulating hormones leptin and ghrelin shifted, and overall appetite was increased, especially for carbohydrate-rich foods (1, 2, 3).
• When young, otherwise healthy sleep-deprived subjects ate breakfast, their glucose levels were significantly higher afterwards than well-rested control subjects - in fact, their response was similar to a pre-diabetic state (1, 2). 

• Avoid Blue Light. Screen use inhibit release of melatonin, an important sleep-regulating hormone. Orange and red light does not seem to have this effect, so you might try using orange-tinted lights or candlelight in the evening, or even wearing orange-tinted glasses after sunset. Melatonin suppression is linked to diabetes , cancer, and other health conditions. To best promote melatonin secretion, avoid screens for 1-2 hours before bedtime.
• Cultivate a Non-Stimulating Routine such as reading, gentle stretching or yoga/meditation, journaling, or bathing - the drop in body temperature you experience after a warm bath may help facilitate entry into deep sleep (1, 2). 
• Exercise. If you have insomnia, be patient - a recent study suggested that it may take up to 4 months of regular exercise for insomnia to improve. Exercise before bed does not seem to affect sleep in healthy people, but researchers caution that people with insomnia may respond differently. Insomniacs seem to have a heightened response to stress, so it is recommended that they complete exercise 2-3 hours before bedtime.  
• "Sleep Hygiene" refers to habits that help promote healthy sleep pattens, and is a topic too vast to fully address here. For a great list of tips to consider, please see this article.