Is sunscreen the new margarine? (2019)
Evidence that moderate sun exposure may reduce blood pressure and overall mortality is challenging long‑standing “avoid the sun” messaging and heavy reliance on sunscreen. Commenters weigh the tradeoff between higher skin‑cancer risk and potentially lower rates of cardiovascular disease and other benefits linked to UV and broader sunlight, noting that past public health advice may have overcorrected against any unprotected exposure. Many land on a pragmatic middle ground: brief daily sun on bare skin, more rigorous protection (clothing or sunscreen) during high‑UV periods, and skepticism toward both extreme avoidance and uncritical anti‑sunscreen narratives.
Overall stance on sun vs. sunscreen / “moderation”
- Many argue some unprotected sun exposure is beneficial (vitamin D, possible cardiovascular effects), but “baking” at high UV is seen as harmful.
- A common takeaway: brief daily exposure on unprotected skin, then protection (clothing or sunscreen) for longer/outdoor activities.
- Others push back that the main practical message remains: avoid burns and chronic overexposure; moderate use of sunscreen and sun is reasonable.
UV index, clouds, and timing
- Simple “10am–5pm” rules are criticized; people emphasize using UV index (protection recommended when >2).
- Several note high UV even on overcast days and report getting severe burns under clouds; visual brightness is not a reliable guide.
- Widgets and tools to monitor real-time UV are seen as helpful.
Sunscreen use, types, and reapplication
- Sunscreen is acknowledged as partial, not total, UV blocker; even diligent users get some UV.
- Some suggest clothing is often preferable, but face and hands still need sunscreen.
- Debate on “reapply every 2 hours”: some say physics and photostability demand it; others cite weak evidence for the exact interval and call it a “ghost citation.”
- Mineral vs. chemical sunscreens are contrasted; mineral filters don’t degrade as much in sun but can still rub off.
- Concerns about certain chemical filters (e.g., oxybenzone) lead some to favor mineral products or newer filters used outside the US.
Photoaging and cosmetic effects
- Strong agreement that UV drives visible aging: wrinkles, spots, leathery skin, asymmetric damage (e.g., truck drivers, outdoor workers).
- Some argue preserving appearance is a major reason for daily sunscreen, independent of cancer risk.
- Others say they’d rather accept looking older than wear extreme covering or constant sunscreen.
Health outcomes, studies, and skepticism
- Cited research suggests more sun exposure correlates with lower blood pressure and lower all-cause mortality, with skin cancer deaths comparatively rare.
- Multiple commenters stress correlation vs. causation: outdoor time also means more exercise, lower stress, better screening, etc.
- Some think the article underplays skin cancer risks; others think current “avoid the sun” messaging overshoots, especially given cardiovascular risk.
- Calls for more rigorous, controlled research; some characterize the article’s anti-sunscreen-adjacent narrative as speculative or biased.
Regional and individual variation
- Australia noted as an outlier: very high UV, fair-skinned population, ozone issues, strong skin-cancer culture.
- High-elevation locations (e.g., Denver) and hostels/outdoor jobs illustrate how chronic sun reshapes skin.
- People differ in tanning, freckling, and blood-pressure responses; some advice may mainly target higher-risk or less healthy populations.
Tools, rules of thumb, and open questions
- A web app (sunburntimer) and Home Assistant integrations use current UV and skin type to estimate safe exposure; praised but criticized because damage is cumulative, not just about “not burning.”
- Open questions remain around: exact safe cumulative UV doses, UVA vs. UVB balance for vitamin D vs. damage, appropriate vitamin D levels, and whether indoor UV lamps or nitric oxide supplements can safely mimic sun benefits.