Health Nugget SUNSHINE 1
The Sun is the source of almost all the energy on earth. Even the energy from hydroelectric plants ultimately comes from the sun. 2
Hydroelectricity is derived from the force of large rivers descending from mountainous areas. It all starts with the sun warming the air. Warm air is capable of absorbing water. When sun-warmed air passes over the oceans, it absorbs water from the oceans. Then, as this air passes over land and moves up to higher elevations, it cools and cool air cannot hold as much water as when warm, so some of the water precipitates out, usually as rain or snow, in the mountains. This precipitation feeds the rivers. 3
The sun is also the source of almost all light and warmth. Life cannot exist without sunlight. The sun produces light and heat and is used by plants to photosynthesize their food and oxygen. Coal and oil are chemical energy from fossil plants. 4
Types of Light (Dysinger) Ultraviolet (UV) short waves, 5% (4.6%, 3%); ultraviolet means beyond violet. The color violet has the highest frequencies of visible light, but ultraviolet has a higher frequency. Visible light 40% (46%, 44%) Infrared long waves, 54% (49%, 53%,) Cosmic rays, gamma rays, x-rays, radio waves, electric waves 1% 5
What passes through glass? Infrared waves Visible light (Ultraviolet light is reflected by the glass, and this is unfortunate, according to Kime, because UV is the most biologically active. In other words, UV light does you the most good.) 6
Zane Kime, Sunlight... Improves electrocardiogram Decreases blood pressure Decreases resting heart rate Increases cardiac output Decreases blood cholesterol Increases glycogen stores in liver Increases some hormones 7
Decreases blood sugar Increases energy, endurance, muscular strength Increases body s resistance to infections Increases oxygen-carrying capacity of the blood Increases resistance of skin to infections 8
Benefits (Dysinger) Most bacteria are killed by two hours of exposure to the sun s UV rays. This is true even through most window glass. But, Kime says that glass reflects UV rays. 9
UV light has 9 subtypes. UV-A 95%, skin aging, wrinkling, contributes to cancer; penetrates the skin deeply; penetrates clouds and glass; is the dominant tanning booth ray; first exposure to tanning beds in youth increases melanoma risk by 75% UV-B chief cause of sunburn; key in skin cancers; do not significantly pass through glass; induces production of vitamin D, lowers BP 10
People cannot perceive UV The lens of the human eye blocks most radiation in the wavelength range of 300 400 nm Shorter wavelengths are blocked by the cornea. Photoreceptors of the retina, however, are sensitive to near-uv, so people lacking a lens can perceive near-uv as whitish blue or whitish violet. 11
Benefits (Dysinger) Most bacteria are killed by two hours of exposure to the sun s UV rays. This is true even through most window glass. (Has to be UV-A) When Kime says the glass blocks the UV, it has to be the UV-B. 12
13
One dose of sunlight to cause minimal redness provides about 20,000 IU of vitamin D2. If adult s arms and legs are exposed to 1/2 minimal dose (10 15 minutes) it is the same as taking 3,000 IU of vitamin D3. Doing this 2 3 times a week will cause a person to produce enough vitamin D. It is not necessary to expose face, as facial skin provides little D3. 14
For fair-skinned people in temperate climates, 15 minutes of sun on clear days 2 3 times a week is sufficient; dark-skinned people require more exposure for the same amount of vitamin D production; and as the skin grows thinner in old age, the amount of vitamin D produced is less. 15
Kime: Increases the number of lymphocytes in circulation Tends to normalize blood pressure Tends to decrease blood cholesterol Lowers blood sugar in diabetics Is a mood elevator, giving an increased sense of well-being and neuromuscular relaxation 16
It makes neutrophils more efficient at ingesting germs. Influences many of the body s hormones, like melatonin and serotonin Stimulates the thyroid gland to increase thyroxine production, which increases body metabolism 17
Harmful to the eyes The UV rays in excessive sunlight is harmful to the eyes (the cornea, the lens, and the retina) UV light and the free radicals it produces are an important stimulant to cataracts. 18
Dark glasses, if they do not absorb UV rays, can do more harm than good because the darkness can cause the pupils to dilate and give even greater exposure to cataract-producing UV rays. All eyeglasses, not just sunglasses, should have UV protection built into them. 19
20
Other cautions... Repeated sunburning is extremely harmful and destroys skin tissue, causing skin to lose its elasticity and protective oil glands, which causes wrinkling and premature aging. AND Sunburn greatly increases the risk of skin cancer. Minimal exposure is good, but avoid any exposure which causes burning or deep tanning. 21
22
1. Seek the shade, 10-4. 2. Do not burn. 3. Avoid tanning and tanning beds. 23
4. Cover up. 5. Use wide-brimmed hat. 6. Use UV blocking sunglasses. 24
25
26
Serotonin Exists in all the organs of the body, including the skin, intestine, lungs, the kidneys, liver, and brain, and exists in nearly every living organism on earth. Serotonin fibers are like a drip irrigation system for the brain and this works well as long as the axons are intact, but in old age and in neuro-degenerative diseases, they degenerate. 27
Dysfunction in brain serotonin is implicated in many mental disorders, such as: autism Down s syndrome anorexia nervosa anxiety and depression 28
alcohol addiction herpes zoster suicide BUT sunlight has a dramatic effect on the brain serotonin system 29
Blood serotonin increases after repeated light exposure... levels were high on bright days. Light therapy relieves suicidal ideation in people with seasonal affective disorder and has a benefit on mood and stability (Efrain C. Azmitia, Handbook of Behavioral Neurobiology of Serotonin) 30
31