Is sunscreen the new margarine? (2019)

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.