Monday, July 15, 2013

Sunlight Boosts Nitric Oxide Production, Lowers Risk of Heart disease, Stroke

Skin exposure to sunshine boosts nitric oxide production and that is a good thing. And researchers have found that the  nitric oxide levels were independent of vitamin D levels. Sunlight triggers healthy metabolism that can reduce the risk of heart disease and stroke.

But many people are worried that they will get melanoma, the most deadly form of skin cancer, if they should get sun exposure without a sun screen. Sun exposure reduces the risk of many conditions and studies show the benefits of sun exposure outweighs the risks. In regards to dying from skin cancer, studies show your risk is 80 times lower on average than your risk of dying from a heart attack or stroke. So it makes sense to work at  lowering your risk for heart attacks and strokes, with getting some sun exposure. 

A recent study by Dr. Weller et al, has some very important conclusions. We need sun exposure as well as good vitamin D blood levels, from sun and from dietary sources to be well. 

Dr. Weller ,lead researcher is quoted as saying:

"We suspect that the benefits to heart health of sunlight will outweigh the risk of skin cancer. The work we have done provides a mechanism that might account for this, and also explains why dietary vitamin D supplements alone will not be able to compensate for lack of sunlight."

I recommend, unless you conciously fit in time for sun exposure that can be proven to give you a vitamin D level above 120 nmol/l, than get as much sun as possible and take a good quality supplement of Vitamin D3, followed with regular blood tests to verify you are getting enough.

There is more here on how to normalize borderline or high blood pressure, the importance of vitamin D, the real incidence of melanoma and the dangerous effects of fructose on the body.

To Your Health
Dr. Barbara

UVA lowers blood pressure and vasodilates the systemic arterial vasculature by mobilisation of cutaneous nitric oxide stores

D Liu,1 BO Fernandez,3 NN Lang,2 JM Gallagher,4 DE Newby,2 M Feelisch3 and RB Weller1,5 1Dermatology, University of Edinburgh, Edinburgh, United Kingdom,2Cardiology, University of Edinburgh, Edinburgh, United Kingdom3Medicine, University of Southampton, Southampton, United Kingdom4Leithmount Surgery, Edinburgh, United Kingdom and 5Centre for Inflammation Research, University of Edinburgh, Edinburgh, United Kingdom
The incidence of hypertension and cardiovascular disease (CVD) correlates with latitude and rises in winter. Population vitamin D levels inversely correlate with CVD, but oral supplementation does not alter CVD rates. Skin contains large stores of nitrite(NO2) and nitrate(NO3). Nitrate is biologically inert, but can be photo-reduced to active NO2 and nitric oxide (NO). The dermal vasculature enables rapid systemic dispersal of NO2 and NO.We hypothesised that ultraviolet A (UVA) mobilises NO bioactivity from skin to circulation to exert beneficial cardiovascular effects. Vit’ D is a marker for sunlight exposure. 24 healthy volunteers were sham (temp’ control) irradiated then actively irradiated with 20 J/cm2 UVA. Mean arterial pressure (MAP) fell and heart rate rose during active but not sham irrad’n (3.50±0.73 mmHg vs 2.80±0.98). The MAP fall was sustained for 50 mins in the active group only. Temperature rise was the same in both groups. Circulatory nitrite rose (0.50±0.04 μM to 0.72±0.04 μM p<0.001) and nitrate fell (11.79± 0.64 μM to 8.99±0.40 μM (p<0.001)) during active, but not sham irradiation. There was no change in circulating vitamin D levels. 12 volunteers had forearm blood flow (FBF) measured by venous plethysmography while 8 μmol/min of the NOS antagonist L-NMMA was infused to the brachial artery. FBF rose during active but not sham irradiation (23.7±6.5 % over baseline vs no change p<.0002). Physiological levels of UVA irradiation cause systemic vasodilation and lower BP in a vitamin D and NOS independent manner. Deaths from CVD and stroke are 60 to 100 times higher than from skin cancers in northern Europe. This study provides a mechanistic explanation for the inverse correlation between sunlight exposure and CVD mortality. Sunlight has beneficial effects independently of vitamin D synthesis.