Sunshine can help with some serious health problems, argues a new book
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- "In Defense of Sunlight" argues that modern sun-avoidance advice has gone too far, documenting surprising ways moderate sun exposure can revitalise the body beyond vitamin D production.
- UV light releases nitric oxide in the skin, which lowers blood pressure — a finding that may explain why Mediterranean populations show lower rates of hypertension.
- The Mediterranean diet works in synergy with sunlight, according to the book: nitrate-rich leafy greens combine with UV-triggered nitric oxide to relax blood vessels more than diet alone.
- Moderate sun exposure releases skin chemicals that calm overactive immune systems, potentially soothing conditions like multiple sclerosis and type 1 diabetes independently of vitamin D.
- Infrared wavelengths in sunlight can penetrate deep into the body and stimulate mitochondria, improving metabolism, the book reports.
- A 20-year Swedish study of 30,000 women found "sun avoiders" were about twice as likely to die as "sun lovers," the book highlights.
- Skin cancer risk is real but most cases are treatable basal or squamous cell carcinomas, Jacobsen notes, while heart disease deaths run about 100 times higher than skin cancer deaths.
Why it matters: For decades, public health messaging has pushed strict sun avoidance; this book argues that advice has overshot, and that 'sun avoiders' in a 20-year Swedish study of 30,000 women were roughly twice as likely to die as 'sun lovers.' The practical implication: brief morning and evening exposure without sunscreen appears to lower blood pressure via nitric oxide and calm immune conditions like multiple sclerosis.
