Very short version:
Avoiding the sun doubles your risk of death.
Short version:
Get sun exposure regularly to be healthy
Chart
The sun is critical to
general health (e.g. Vitamin D and not only)
circadian rhythm (morning sun sets the clock) which then sets your sleep and affects likelihood of all chronic illnesses
happiness ( the sun increases serotonin production, depression correlates with vitamin D deficiency and latitude)
cognition and productivity (study shows sunlight absence impairs cognition)
eyesight (myopia comes from insufficient sunlight).
Start gradually and build up to long daily exposure. Doing it this way does not increase your chances for skin cancer, quite the opposite. Regular sun exposure reduces skin cancer incidence versus people who avoid it most of the time.
Long version
This morning right after I woke up I went outside for a ten minute walk. It was -10 degree Celsius and a small blizzard.
I go outside around dawn every day.
It’s not masochism or fitness.
It’s because it sets my circadian clock so I wake up and then I feel sleepy in the evening. It lifts my mood even if it’s miserable outside like today. It activates my brain to start working instead of moping. It makes coffee a morning pleasure, not a wake-up drug.
It’s one of the many ways in which I get as much sun exposure as I can. Others include working next to a window. Taking a walk at noon, after eating. Working outside when it’s warm. Frequent activities outdoors.
The sun increases my health and wellbeing.
Vitamin D vs Cancer?
“You need to protect your skin from the sun every day, even when it’s cloudy,” American Academy of Dermatology
However doctors have been telling us to avoid the sun for decades. It’s the villain that gives you cancer.
This alarmist messaging has become so powerful that it feels like it’s dangerous to stand even one second in direct sunlight. Dermatologists even recommend sunscreen when indoors now.
Does this sound absurd to you? Our ancestors spent most of their life in the sun. How can it be so harmful?
One benefit of sun exposure which the medical profession recognizes is vitamin D. Your body manufactures vitamin D in response to UV radiation (UV-B to be specific). This vitamin exists in certain foods but only in small quantities. It is impossible to get your requirement of Vitamin D from food alone.
Having deficient levels of vitamin D correlates with: bone health, immunity, cardiovascular disease, multiple cancers, asthma, blood pressure, fat, respiratory infections, COVID-19 severity. There are too many studies to cite, here is the examine.com page which has many of the relevant ones.
I found I had severe vitamin D deficit one year ago. It was awful.
I was a pale copy of myself. No energy, no power, no drive, no clarity of thought. It put me into a crisis of identity because I was incapable of being who I thought I was.
All from vitamin D.
The official response to this problem of insufficient sun exposure is to supplement vitamin D. The message is Take these pills to replace sun exposure.
It is good business. In the U.S. consumer spending on vitamin D supplements quadrupled from 2008 to 2019, exceeding 1 Billion Dollars yearly.
Unfortunately the data on vitamin D supplementation is not positive.
This research, this research and this research show vitamin D supplementation had little benefit in terms of health outcomes. It raised serum levels but did not lower cancer, heart disease, or stroke.
This meta-analysis shows no benefit in muscle health. This study in Danish elderly found that vitamin D supplementation actually correlated with higher bone fracture rates.
Vitamin D deficit correlates with poor health outcomes, but vitamin D supplementation does not improve them.
What is going on?
Vitamin D might not be relevant in isolation. Rather it is a marker for sun exposure. This exposure probably has more effects, not just raising vitamin D levels. Plus, vitamin D slowly produced by your body in response to sunlight exposure is not the same as vitamin D ingested in pills.
We avoid sunlight for fear of cancer. Then supplement to compensate. But the supplements don’t work.
What is the solution? The obvious one would be to get sun exposure, but we run into the fear of cancer.
Let’s look at how much risk of cancer actually comes from sun exposure.
Sun causes cancer? Not so much
Skin cancer is well known because sunscreen companies use it as the boogey man to sell their products.
Yet it is rare. For every person who dies from skin cancer, 100 people die from cardiovascular disease. In the U.S. less than 3 in 100,000 people die from skin cancer yearly.
Who gets melanoma and who does not? Does it depend on sun exposu
Does it depend on sun exposure?
Sunscreen was introduced in the 1940s. If it protected against skin cancer from the sun, then we would see rates of it dropping.
Instead it has been steadily climbing since then. This suggests sunscreen is not useful against melanoma, and might even be a negative factor.
One way sunscreen could be damaging is that it protects against sunburn. But sunburn is a warning mechanism. When you get it, you know to get out of the sun. Without the warning signal, you spend too much time and get sun damage, but don’t feel it.
As we all know, sunburn comes when you do too much at once. Which correlates with melanoma incidence.
Indoor office workers have the same or higher risk of melanoma as people with outdoors professions. If you are an accountant you have maybe higher risk than the construction worker. This is despite getting an estimated 10 times less UV exposure.
Another study in Sweden found that people who are regularly exposed to the sun are more likely to get melanomas. But they are eight times less likely to die from them.
When you are usually not exposed to the sun, but then go on a 3 day beach holiday you overload your body’s defenses. The result: cancer. If you are exposed regularly, your body adapts. You also learn to avoid sunburn and thus prevent the damage.
"Tumour development may be linked to occasional exposure to short periods of intense sunlight, such as at weekends or on holiday. The higher incidence of malignant melanoma in indoor workers compared to outdoor workers supports that notion." World Health Organisation
Rare sun exposure increases risk of melanomas.
To prevent melanomas, you could either avoid the sun completely or adapt to constant sun exposure.
Our natural environment is the sun
All early humans evolved outdoors beneath a tropical sun. Like air, water, and food, sunlight was a key part of our environment. Our bodies evolved to protect our skin from receiving too much radiation through melanin, a natural sunscreen. Our dark-skinned African ancestors produced so much of it that they did not worry about the sun.
As humans migrated to northern latitudes and faced months of light shortages each winter, they evolved to produce less melanin when the sun was weak, to absorb as much sun as possible. They also produced much more of a protein that stores vitamin D for later use. In spring, the sun provided more UV and they gradually form a sun-blocking tan.
Sunburn was a rarity until we began spending most time indoors. Now, pale office workers went to the beach in summer and got a sudden overload of strong sun. They got sunburn and melanoma.
Dark skinned people rarely get melanoma. The rate is 3.2 per 100,000 in Caucasians, 0.8 per 100,000 in Hispanics, and 0.4 per 100,000 in Black People, 0.3 per 100,000 in Asian/Pacific Islander. On the rare occasion when African Americans get melanoma, it’s especially lethal. However it is mostly a specific type which appears on the palms, soles, or under the nails. It is not caused by sun exposure.
Sun = life
Sun is great for health.
Many things are said to be good for health. It can be hard to distinguish the magnitude of impact. For sun we can make it simple:
Sun avoidance doubles your risk of death.
A study published in Journal of Internal Medicine followed 30,000 women in Sweden over 20 years. It compared women who avoided the sun to those who exposed themselves to it. Initially it looked at blood clots (less often in sun worshipers), diabetes (less in sun worshipers), melanoma (higher in sun worshipers but they were eight times less likely to die from it). Then the researchers looked at overall mortality and found that women who avoided the sun were twice more likely to die within this timespan than those who exposed themselves to it.
“Avoidance of sun exposure is a risk factor of a similar magnitude as smoking, in terms of life expectancy.” says lead researcher in this study Dr. Pelle Lindqvist.
What to do
Gradually expose yourself to the sun each day.
It’s harder in a big city, but not impossible. Wear short sleeves. Go out for a walk as a break from work. Eat out when it is warm enough.
Each week try to get a little more exposure. At the first feeling of sunburn, back off. Avoid exposure for a few days to give your body time to heal.
Get morning light every day. You need a certain amount of light exposure to tell your body that it has woken up and the day has started. If you don’t get it when you wake up, then your circadian clock is delayed. This will imbalance your sleep which then has major negative effects.
Depending on the season and latitude, optimize for different times of day. If you live at the Ecuator, avoid noon year long because there is very high UV. The farther north you live, the more seasonal it gets. Where I live now, there is no UVB in most of winter for example. The more Northern you live, the more you should seek out noon during low UV months and avoid it in peak summer.
Adjust for your skin tone. The darker you are, the more sunlight you need. This is especially true if you live in a Northern latitude when UV-B decreases or disappears during winter months. You need to build up for those periods. On the other side, if you are pale, you need to be more careful in creating gradual adaptation. Avoid sunburn with clothes rather than sunscreen. Push for more exposure, but don’t overdo it at once.
Don’t wear sunglasses. There are cells in the eyes which detect how much light hits your body. These are your body’s way to measure how much light exposure you are getting.
It is reasonable to assume that they influence your skin’s response to light. IF the eyes detect more light, then the skin darkens more. This is a theory, I don’t know of any scientific study proving this yet, but better safe than sorry.
The implication is that sunglasses will increase your chance of sun damage. They fool the body into thinking less light is hitting it than the reality. Again, it’s not proven. But our ancestors did not have RayBan-s so there is a possibility it is true.
I have not worn sunglasses in three years. I go out into the sun a lot. Most people say excessively. I never wear sunscreen. I have not gotten a single sunburn in these three years.
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Further reading:
Circadian Code - Satchin Panda
Why we sleep - Matthew Walker
The World Until Yesterday - Jared Diamond
Guns, Germs and Steel - Jared Diamond
Why the West Rules, For Now - Ian Morris
Lifespan - David Sinclair