my-no-soap-no-shampoo-bacteria-rich-hygiene-experiment.
Gemma says:
There was perhaps too much nitrogen in my original comment, so
here goes some science to de-confuse the dear reader (on the interplay
of sun, nitrogen, ammonia-oxidizing bacteria and CVD health):
Is sunlight good for our heart?
“We propose here that many of the beneficial effects of sunlight, particularly those related to cardiovascular health, are mediated by mechanisms that are independent of melatonin, vitamin D, and exposure to UVB alone. Specifically, we suggest that the skin is a significant store of nitric oxide (NO)-related species that can be mobilized by sunlight and delivered to the systemic circulation to exert coronary vasodilator and cardioprotective as well as antihypertensive effects (Figure 1). We further hypothesize that this dermal NO reservoir is a product of local production and dietary supply with nitrate-rich foods.
[...]
A recent human study has demonstrated that UVA irradiation can increase plasma nitrite levels by 40%. This is intriguing considering that in animal models, a similar increase in nitrite is associated with cardioprotection following I/R injury. Dietary nitrate intake (predominantly from green leafy vegetables) may provide an alternative source of nitrite.”
http://eurheartj.oxfordjournals.org/content/early/2010/03/09/eurheartj.ehq069.full
Gemma says:
Is sunlight good for our heart?
“We propose here that many of the beneficial effects of sunlight, particularly those related to cardiovascular health, are mediated by mechanisms that are independent of melatonin, vitamin D, and exposure to UVB alone. Specifically, we suggest that the skin is a significant store of nitric oxide (NO)-related species that can be mobilized by sunlight and delivered to the systemic circulation to exert coronary vasodilator and cardioprotective as well as antihypertensive effects (Figure 1). We further hypothesize that this dermal NO reservoir is a product of local production and dietary supply with nitrate-rich foods.
[...]
A recent human study has demonstrated that UVA irradiation can increase plasma nitrite levels by 40%. This is intriguing considering that in animal models, a similar increase in nitrite is associated with cardioprotection following I/R injury. Dietary nitrate intake (predominantly from green leafy vegetables) may provide an alternative source of nitrite.”
http://eurheartj.oxfordjournals.org/content/early/2010/03/09/eurheartj.ehq069.full
Gemma says:
And now on the importance of the ammonia oxidising bacteria (AOB) living on the skin:
Soil bacteria, nitrite and the skin
“Mammals likely evolved with AOB on their skin, providing their host with nitrite by conversion of ammonia in providing their host with nitrite by conversion of ammonia in sweat with scalp, pubic and underarm hair providing a suitable niche due to enhanced sweat production, increased warmth, increased relative humidity and protection of light (the latter is important as ammonia monooxygenase activity is inhibited by light). Low NO increases androgen levels which increase growth of pubic hair, expanding the AOB niche thereby increasing NO/NOx production and absorption in a feedback loop.
The production of a suitable niche for these bacteria provides a rationale for non-thermal sweating (e.g., under stress) (to supply NO/nitrites, the location of body hair (near lymph nodes), why the skin of the scalp is thin and well vascularized (to enhance NO/nitrite absorption), any why the sweat glands are most abundant on the feet and palms (fro antimicrobial effects of acidified nitrite in surfaces in contact with soil).
http://www.researchgate.net/publication/227124248_Soil_bacteria_nitrite_and_the_skin
(full text available)
Soil bacteria, nitrite and the skin
“Mammals likely evolved with AOB on their skin, providing their host with nitrite by conversion of ammonia in providing their host with nitrite by conversion of ammonia in sweat with scalp, pubic and underarm hair providing a suitable niche due to enhanced sweat production, increased warmth, increased relative humidity and protection of light (the latter is important as ammonia monooxygenase activity is inhibited by light). Low NO increases androgen levels which increase growth of pubic hair, expanding the AOB niche thereby increasing NO/NOx production and absorption in a feedback loop.
The production of a suitable niche for these bacteria provides a rationale for non-thermal sweating (e.g., under stress) (to supply NO/nitrites, the location of body hair (near lymph nodes), why the skin of the scalp is thin and well vascularized (to enhance NO/nitrite absorption), any why the sweat glands are most abundant on the feet and palms (fro antimicrobial effects of acidified nitrite in surfaces in contact with soil).
http://www.researchgate.net/publication/227124248_Soil_bacteria_nitrite_and_the_skin
(full text available)
