What’s the alternative? Scientists are constantly changing their minds, research is conflicting, and there is too much variability between people for a reliable prescription.
There could be psychological associations with comfort food or there could be nutritional.
Actually dirt is very iron-rich, especially the red and yellow clays which are mostly iron oxide, but iron isn’t the issue; it’s calcium and why dirt is consumed mostly by pregnant women and children (developing skeletons).
[i]In Africa, kaolin, sometimes known as kalaba (in Gabon[10] and Cameroon[11]), calaba, and calabachop (in Equatorial Guinea), is eaten for pleasure or to suppress hunger.[11] Kaolin for human consumption is sold at most markets in Cameroon and is often flavoured with spices such as black pepper and cardamom.[12] Consumption is greatest among women, especially during pregnancy.[13] Another example of geophagia was reported in Free State Province in South Africa, where the practice was geochemically investigated.[14]
In Haiti, poor people are known to eat biscuits made from soil, salt, and vegetable shortening. These biscuits hold minimal nutritional value, but manage to keep the poor alive.[15] However, long-term consumption of the biscuits is reported to cause stomach pains and malnutrition, and is not recommended by doctors.[16]
In the United States, cooked, baked, and processed dirt and clay are sold in health food stores and rural flea markets in the South.[17] In the rural areas of Mississippi and other southern states, the consumption of clay-rich dirt has been a common custom and has been practiced by poor white and black people for generations.[18] However, geophagia has become less prevalent as rural Americans assimilate into urban culture.[7]
Bentonite clay is available worldwide as a digestive aid; kaolin is also widely used as a digestive aid and as the base for some medicines. Attapulgite, another type of clay, is an active ingredient in many anti-diarrheal medicines.[7][/i] en.wikipedia.org/wiki/Geophagia
In the southeast US, calcium is hard to find in locally grown food because of the deluge of rainfall annually. Calcium and sulfur are the main elements leached from dirt in rain; hence why the soil is acid and why the people are stereotypically toothless.
William Albrecht noted 7 out of 10 men were drafted into WWII from the midwest compared with 7 out of 10 rejections for the southeast, which he attributed to the rainfall differences designerecosystems.com/2014/10/1 … -albrecht/
William A. Albrecht (1888–1974) PhD,[1][2] chairman of the Department of Soils at the University of Missouri, was the foremost authority on the relation of soil fertility to human health and earned four degrees from the University of Illinois. As emeritus professor of soils at the University of Missouri, he saw a direct link between soil quality, food quality and human health. en.wikipedia.org/wiki/William_Albrecht
It’s fascinating to read his research.
For instance the world’s foremost expert on soil said:
“Here was a case where we as researchers—who are merely trying to learn more—discovered that the cow was a better soil chemist and biochemist than we are.” soilandhealth.org/wp-conten … health.pdf
He was referring to the fact that cows were able to discern that grass was merely goosed with nitrogen and is otherwise void of nutrition, so the cow refused to eat what looked lush and green to us and we would need laboratory equipment to determine what the cow can see plainly. He noted that animals have a remarkable ability to instinctually self-medicate.
The instincts of animals are compelling us to recognize soil differences. Not only do dumb beasts select herbage according as they are more carbonaceous or proteinaceous, but they select from the same kind of grain the offerings according to the different fertilizers with which the soil was treated.
If animals can do it, no doubt we can too.
As far as I know, greenhouse lights are high-pressure sodium and metal halide.
There are spectrums here
en.wikipedia.org/wiki/Metal-halide_lamp
en.wikipedia.org/wiki/Sodium-vapor_lamp
HPS is a bit redder.
Then there are fluorescents which come in various color temperatures.
There are some example spectra here: en.wikipedia.org/wiki/Fluorescent_lamp
On down the page it says “A 1993 study in the US found that ultraviolet exposure from sitting under fluorescent lights for eight hours is equivalent to one minute of sun exposure.”
Then there are leds, which are tuned for optimal plant growth by including so many red bulbs and so many blue with a few UV. (I’ve read a couple reviewers on amazon attributing these lights to cataracts, so always wear glasses around them)
With leds, you can pick any bulb you want and solder it onto the board, but each led only outputs a narrow spectrum, so you’d need a lot to mimic sunlight.
Here is a typical led setup: 410nm, 430~440nm, 450~475nm, 620~630nm, 650~670nm, White, IR(730nm) amazon.com/Light%EF%BC%8C18 … B075XCSHHW
Tanning beds are notorious for adverse effects. aad.org/media/stats/prevention-and-care
Who knows what bulbs are inside?
I suspect the problem is imbalance of UVB/UVA.
UVA gives a quick tan that lasts for days by oxidizing melanin that was already present and triggers the release of the melanin from melanocytes. UVB yields a tan that takes roughly 2 days to develop because it stimulates the body to produce more melanin.
Several studies suggest that the absence of UVA filters may be the cause of the higher incidence of melanoma found in sunscreen users compared to non-users.[64][65][66][67][68] Some sunscreen lotions now contain compounds including titanium dioxide, zinc oxide and avobenzone which helps protect against UVA rays. en.wikipedia.org/wiki/Ultraviolet
So, blocking UVB results in more cancer than not blocking anything.
I can’t find it succinctly said, but I know I’ve read somewhere that UVA and UVB antagonize each other such that the harmful effects of each are cancelled. It’s been a few years since I’ve studied this.
Here’s this sciencedirect.com/science/a … 2X15335491
The observations suggest that UVA reduces UVB-induced DNA damage
And here sciencedirect.com/science/a … 2X15402362
The incidence of skin cancer detected in human populations submitted to high levels of solar radiation seems to be less than what would be expected taking into account the amount of damage inflicted on cellular DNA by solar UV fluence and the repair capability of the cells (Sutherland 1996). This means that (i) the solar UV damaging potential has been overestimated, (ii) the repair potential of the cells has been underestimated, or (iii) the effects of UV in a polychromatic light beam are not the same as those of monochromatic UV, due to as yet unknown antagonistic effects. Although sunlight is polychromatic, its final effect on human skin is the result of not only the action of each wavelength individually, but also the interactions between these wavelengths.
Anyway, I have it in my head, from prior research, that one should not be exposed to sun outside of the 10am to 2pm band due to over-expression of UVA without supporting UVB. One should avoid tanning beds for the same reason. And tinkering with artificial lights is risky.
The sun will never give too much UVB because UVA always exceeds UVB, but artificial lights can. However, most lights will be UVA without much UVB. Rather than all this head-scratching, it’s easier to just go outside around lunch time