The short answer is: on its own, no, sunlight cannot cure high blood pressure.
But sunlight can reduce blood pressure because sunshine provides us with vitamin D which helps restore our body’s natural balance. And this includes regulating blood pressure.
If you live up north like me (Wales), it’s the sunlight a few hours either side of noon that you need because that’s when the UVB rays necessary for vitamin D synthesis are best received.
Sunlight also stimulates our skin to produce nitric oxide, which relaxes our blood vessels – so sunshine lowers blood pressure this way too.
So when the sun shines around midday – get out there and expose yourself. It’s good for you!
Sunshine and human health
Each day, Apollo’s fiery chariot makes its way across the sky, bringing life-giving light to the planet. For the ancient Greeks and Romans, Apollo was the god of medicine and healing as well as of sun and light—but Apollo could bring sickness as well as cure. Today’s scientists have come to a similarly dichotomous recognition that exposure to the ultraviolet radiation (UVR) in sunlight has both beneficial and deleterious effects on human health.
M. Nathaniel Mead, Environmental Health Perspectives, 2008
Humans have probably always worshipped the sun. Long before we got obsessed by the perfect sun tan, humans revered solar gods and goddesses. In Japan the Emperor is still said to be descended from the sun. Our solar focus didn’t wane when we developed science either. In the last century, doctors often sent patients to sanatoriums in warm countries for fresh air and sunshine to cure TB, rheumatic disorders and all kinds of other things.
Obviously, more recently, there’s been concern about the fact that getting too much sun can lead to skin cancer. While this is definitely something to be careful of, by avoiding the sun too much, we’re actually more likely to get other kinds of cancers. This is because if we don’t get enough sun, we’re probably not making enough vitamin D. Studies now show that vitamin D inhibits the growth of abnormal cells. As such, it helps protect us from cancers (such as breast, prostate and colon cancer).
So now, things have come full circle. With our indoor lifestyles and diligent use of sunscreen, we might be making ourselves ill by not getting enough good old sunshine onto our skin.
How can sunlight reduce high blood pressure?
Basically, sunshine can reduce high blood pressure because sunshine increases your vitamin D levels and Vitamin D helps reduce blood pressure.
How sunlight triggers the production of vitamin D in your skin
Sunlight is made up of a whole spectrum of different wavelengths of radiation. One particular kind – UVB radiation – triggers a reaction in your skin which uses the energy of sunlight to create vitamin D. Basically, you’re photosynthesising like a plant, although with different chemical processes.
How vitamin D helps reduce blood pressure
Researchers reckon there are a number of ways in which vitamin D helps reduce blood pressure, and have a protective effect on the heart.
Firstly, vitamin D helps lower blood pressure through its effects on the renin-angiotensin system. These are hormones which regulate fluid levels and blood pressure CHECK. INot having enough vitamin D usually results in this system being overactive, putting you more at risk of high blood pressure as well as heart attack and stroke.
Secondly, vitamin D has been found to relax the muscle cells found in the walls of our blood vessels.
Thirdly, your body needs sufficient vitamin D to absorb calcium effectively. As well as being important for healthy bones, calcium interacts with magnesium to lower blood pressure.
Read our article here for more details on Vitamin D and blood pressure
Another way in which sunlight lowers blood pressure
Another kind of radiation present in sunlight – UVA radiation – can also reduce blood pressure. Recent studies show that UVA rays stimulate nitric oxide to be released. Nitric oxide is known to dilate the blood vessels and thus lower blood pressure.
In one study, diastolic blood pressure dropped by 5 mmHg upon UVA exposure, and stayed that low for half an hour afterwards.
Evidence for sunlight reducing high blood pressure
It might seem quite hard to believe that something as simple as sunshine can lower blood pressure. However, the evidence is piling up.
For example, researchers at a university in Berlin used special sunbeds to measure the effects of UV radiation on vitamin D levels and blood pressure. People with high blood pressure used the sunbeds for a short period every day for three months. Half the participants used a sunbed which bathed them in full-spectrum UV radiation, similar to summer sunlight. The other half used a sunbed which emitted UVA-only radiation, which is similar to winter sunlight. After three months, the group who’d had the full-spectrum UV light had (on average) an 180% increase in their vitamin D levels and a 6 mm Hg decrease in their blood pressure (systolic and diastolic). The other group, who got UVA only didn’t show any difference in their vitamin D levels or blood pressure.
NOTE: This does not mean that using sunbeds will increase your vitamin D levels! This is because most sunbeds mostly emit UVA radiation, rather than UVB (which is what you need to make vitamin D).
In general, the importance of natural sunlight for our health is gradually being recognised worldwide. The US National Institute of Health (NIH), for example, now recommends getting some exposure to the sun in order to increase vitamin D levels.
How to safely get enough sunshine to reduce high blood pressure?
But isn’t it unsafe to get too much sun? Certainly, that’s the message we’ve been getting from health authorities for years now. Sunshine can cause skin cancer at worst, sunburn at best, right? Well, while it’s undoubtedly true that too much sunshine on your skin can have all kinds of damaging effects on your body, it has a lot of benefits too. Some of these benefits are crucial to our health and well-being. For example, sunlight in the eyes and on the skin is essential for maintaining our circadian rhythms effectively.
Sunlight – through vitamin D production – has myriad other positive effects, including supporting the immune system, ensuring healthy bone development, as well as protecting you against high blood pressure and heart disease, some cancers, multiple sclerosis, TB and potentially quite a few other diseases as well.
Oh, and exposure to sunlight (through your skin and through your eyes) can stimulate the production of neurochemicals like serotonin and endorphins, both of which tend to make you feel good. Sunshine makes you happy!
A good amount of sunshine
The key to not experiencing the adverse effects of sunshine is to make sure you’re not getting too much.
But how much is too much? It’s a bit tricky because different health authorities and scientists give different recommendations. What’s a safe solar threshold can also be different for each person. And of course, where you are in the world and how strong the sunshine is will make a big difference: at any time of day, you’re less likely to get sunburnt in Scotland than in Senegal (although you can still get sunburnt in Scotland!).
How much vitamin D you can make is also affected by these factors. The paler your skin (not just the skin colour you’re born with but how tanned you are) the more vitamin D you make from the same amount of sunshine.
For most white people, a half-hour in the summer sun in a bathing suit can initiate the release of 50,000 IU (1.25 mg) vitamin D into the circulation within 24 hours of exposure; this same amount of exposure yields 20,000–30,000 IU in tanned individuals and 8,000–10,000 IU in dark-skinned people.
M. Nathaniel Mead, Environmental Health Perspectives, 2008
One thing to note is that repeated brief periods of exposure are not only safer but also more efficient at producing vitamin D. And since some sunlight can get through sunscreens, Dermatology professor Barbara A. Gilchrest of Boston University School of Medicine recommends going out in the sun with sunscreen and also taking vitamin D supplements.
A good guideline is to get enough sun to start to give you a very light tan, but without any skin reddening. This is roughly about a quarter of the time it would take for you to start to get sunburned. For many people, this could just be about quarter of an hour in the sun, with as little clothing as possible!
The right type of sunshine
In terms of producing vitamin D, it’s crucial that you’re getting the right kind of sunlight. As mentioned above, UVB radiation is what you need to produce vitamin D. But UVB isn’t always present in the sunlight that’s reaching you. UVB can be easily blocked by clouds, fog, smog, and by the ozone layer if the radiation is coming in at a bit of an angle.
So, the higher the latitude you live at, the more acute the angle at which the sun is reaching you. This means less UVB is present in it. The best time to be getting maximum UVB radiation, therefore, is when the sun is highest in the sky at noon. By which I mean, actual astronomical noon. In other words, about 1 pm in summertime if you’re in a country that puts the clocks forward an hour in the spring.
UVB is also partly blocked by glass so it’s not enough to sit by a window. You need to actually get outside.
What if you can’t get enough sunlight to reduce high blood pressure?
If you live at higher latitudes, as in most of northern Europe, the northern US and Canada, then it’s unlikely you’re ever getting enough sunshine to make a healthy amount of vitamin D. Especially in the winter.
You’re also not likely to be getting enough vitamin D through your food and drink (unless, like Arctic peoples, you eat a lot of seals).
Vitamin D supplements
So the chances are, you need to take vitamin D supplements, at least in the winter and possibly all year. In Scotland, health authorities now recommend everyone take vitamin D supplements all year.
As to how much you should take, there’s more information on vitamin D levels and supplementation in our other article here: Vitamin D and high blood pressure
You can buy a good quality vitamin D3 supplement online here: Vitamin D3 (CLE Holistic Health)
You can also eat more food which contain vitamin D, such as eggs and fatty fish like salmon, mackerel, herring, trout and kippers. (Personally, I wouldn’t eat too much farmed fish like salmon. Such fish are not only soaked in antibiotics and pesticides but have awful lives crammed into pens while being munched by sea lice.)
The full solar spectrum is essential to optimal health and well-being. Humans are physiologically adapted to produce vitamin D in response to sun exposure, specifically UVB radiation; other regions of the spectrum seem to confer benefit as well. Though some vitamin D comes from our diet (and more recently from supplements), we should not ignore the natural capacity that we possess to produce our own.
We are of the opinion that moderate sun exposure (less than the time required to burn) to the arms, shoulders, trunk, and legs should be sought rather than avoided. Once that limited time has been achieved, we agree that covering the skin or seeking shade may be appropriate. The benefits of such exposure go beyond production of vitamin D and include other physiological responses to sunlight, still inadequately explored, including release of nitric oxide, production of beta-endorphin, and regulation of circadian rhythms—all important components of lifelong health and well-being.
Baggerly et al, Journal of the American College of Nutrition, 2015
Sun is life. Enjoy it while it’s out.
And while it’s not, take vitamin D supplements!
Lower Your Blood Pressure Naturally for Life
Getting enough sunlight and vitamin D is one step towards managing high blood pressure. However there’s a lot more you can do to lower your blood pressure naturally.
For a start, there’s a large choice of affordable natural ingredients that lower blood pressure. Many of these spices, herbs, berries, fruits, grains, vegetables, meats and drinks are available in local stores.
This might sound daunting, especially if you’re just starting out on this route to better blood pressure. However, most of these changes can be incorporated quite easily into your everyday life.
To make it simple, we’ve put together a complete guide to lowering your blood pressure naturally:
The guide is laid out in 9 straightforward steps. Just follow the advice for each step. You can take it a week at a time or a month at a time, whatever suits you. Then you can enjoy knowing that you’re now on your way to lower blood pressure and better health in general.
Not only is the guide easy to follow but it’s also enjoyable to follow, with lots of tasty food and drink suggestions and useful tips on lifestyle changes. Little things that, when combined, can make a big difference.
Lowering your blood pressure naturally doesn’t have to be an endurance test 😉
To download a sample of the guide to your computer right now click here and scroll to the bottom of the page for the download link.
Can sunlight reduce blood pressure? Some references
Benefits of Sunlight: A Bright Spot for Human Health (Environmental Health Perspectives) *recommended read! Covers the whole debate (historically and now) about the role of sunlight in human health, including information about sunshine and hypertension.