More sun exposure means longer lifespan and better mood

For decades, we’ve been told how dangerous the sun is and how important it is to protect ourselves. Now, a large British population study of more than half a million participants reveals that getting more sun exposure – even using tanning beds – is linked to fewer deaths from cardiovascular disease, cancer, and other things. The explanation lies in the UVB rays, which are the best way to get essential vitamin D, but only when the sun sits sufficiently high in the sky. It appears that all the sun awareness campaigns have done more harm than good, because it is vital to get enough sunlight, as long as we don’t get burned. The British study supports an earlier Swedish population study that revealed that lack of sun is every bit as harmful as smoking. People should take a vitamin D supplement during the winter period, and those who don’t get enough sun or who have difficulty with synthesizing vitamin D should supplement all year round.

The new British study is a prospective population study with more than half a million participants from England, Wales, and Scotland. It looked at the diet habits, lifestyle, and health of people recruited from the UK Biobank. The study revealed an inverse relation between exposure to UV radiation and the risk of dying early from cardiovascular disease, cancer, and other ailments. Apparently, sun exposure and UV radiation have a highly positive impact on health in northern-European regions like the UK and Scandinavia, primarily during the summer period where the sun sits high in the sky. The study also showed that people who used tanning beds had a lower risk of cardiovascular disease and cancer.
The study is published in Health & Place and supports an earlier Swedish population study where researchers monitored nearly 30,000 women aged 25-64 years for 20 years to find out more about their sun habits. The study, which is published in Journal of Internal Medicine, showed that women who got plenty of sun had a lower risk of dying of cardiovascular disease and generally lived longer than women who did not get out in the sun on a regular basis. The researchers even found that women who avoided the sun and did not smoke had the same life expectancy as the women who smoked and got out in the sun. Apparently, avoiding the sun is just as bad for you as smoking.

• Excessive sunbathing, especially if you get burned, increases the risk of the dangerous type of skin cancer called melanoma
• During the period between 2017-2019, melanoma only accounted for one percent of all cancer-related deaths
• Sunbathing lowers the risk of several other cancer forms, cardiovascular disease and other diseases, and early death
• The health benefits of regular sunbathing outweigh the disadvantages

The biological mechanisms that involve sunlight, health, mood, and sleep quality

In their introduction, the study authors describe the biological effect the sun’s UVA and UVB rays have on our health. UVB rays are necessary for our ability to synthesize vitamin D in our skin with help from a cholesterol precursor. Most cells in the body have vitamin D receptors (VDR). Vitamin D is viewed as a steroid hormone, and it controls a host of different gene activities. Numerous studies have shown that having higher blood levels of vitamin D (above 75 nmol/L) is linked to a lower risk of infections, circulatory diseases, cancer, and many other ailments.
The UVA rays in sunlight penetrate into the deeper skin layers. This increases the production of nitric oxide that has a blood pressure lowering effect. Nitric oxide can also inhibit chronic inflammation that is involved in type 2 diabetes, atherosclerosis, and most other chronic diseases. Newer studies show that the sun’s UVA rays protect against heart infarction and the risk of dying of COVID-19, independently of the UVB rays.
Also, sunlight affects our pineal gland, causing us to produce more serotonin during the day. This is good for our mood. When it gets dark outside, serotonin influences our melatonin synthesis, and this hormone helps us sleep. Melatonin also has other essential functions, and science is currently focusing on the prevention of cancer, Alzheimer’s disease, depression, and many other ailments. According to a previous review article published in Nutrients, vitamin D and melatonin appear to work as a hormonal team that is important for many essential processes.

• At northern latitudes, we are only able to synthesize vitamin D during the summer period where the sun sits high in the sky
• It is impossible to produce too much vitamin D through dermal synthesis (the natural vitamin D production in the skin)
• Dark skin, sunscreen use, ageing, type 2 diabetes, and having a high BMI impairs the body’s absorption and utilization of vitamin D
• People living at northern latitudes are advised to take vitamin D during the winter period. Those who don’t get enough sun exposure of have difficulty with synthesizing vitamin D should take a supplement all year round.
• The recommended vitamin D intake level is no guarantee of optimizing blood levels of the nutrient
• Blood levels of vitamin D should ideally be above 75 nmol/L

References:

Andrew C. Stevenson et al. Higher ultraviolet light exposure is associated with lower mortality: An analysis of data from the UK biobank cohort study. Health & Place 2024

Lindquist PG, Epstein E, Nielsen K et al. Avoidance of sun exposure as a risk factor for major causes of death: a competing risk analysis of the melanoma in Southern Sweden cohort. Journal of Internal Medicine. 2016

Deanna M. Minich et al. Is Melatonin the ”Next Vitamin D”?: A review of Emerging Science, Clinical Uses, Safety, and Dietary Supplements. Nutrients 2022