Dietary omega-3 polyunsaturated fatty acids as a protective factor of myopia

Original Article ↗ Hacker News Discussion ↗

Study quality and interpretation

  • Several commenters call the myopia study underpowered (n≈1000, ages 6–8 only) and “shotgun” (many nutrients vs many eye measures), flagging high p‑hacking risk.
  • Others note likely “healthy user bias” (kids with better diets may differ in many ways) and see the result more as a hypothesis generator than proof.
  • Some argue it should be replicated in other populations; others counter that effects may be population‑specific (diet, genetics), so broad null results could hide real subgroup effects.

Omega‑3, myopia, and eye health

  • Thread accepts that omega‑3 is plausibly helpful for retina/brain and possibly myopia, but stresses that evidence across conditions is mixed and often weaker in larger trials.
  • Mechanistic speculation includes omega‑3’s impact on triglycerides/insulin and glucose‑related eye damage.
  • Anecdotes: fish oil prescribed or self‑used for dry eyes, blepharitis, floaters, with some reporting clear benefit and others none.

Sources and biochemistry

  • Repeated distinction between ALA (plant omega‑3 from flax, chia, walnuts) vs EPA/DHA (from fish/“algae”/Schizochytrium); conversion from ALA is described as inefficient, especially in men and older people.
  • Strong preference by many for direct EPA/DHA from fatty fish, cod liver oil, or microbe‑derived oils; skepticism toward canola/soybean oil as meaningful omega‑3 sources.
  • Algal (Schizochytrium) oils noted as DHA‑dominant initially but now available with EPA; still substantially more expensive than fish oil.

Supplement quality, dosing, and risks

  • Rancidity is a major concern: suggestions include high‑turnover brands, refrigeration, tasting bottled oil, and skepticism of flavored products that may mask off‑flavors.
  • Heavy metals seen as less of an issue in distilled fish oil, more in some “natural” oils and whole fish; krill and algal oils discussed as alternatives.
  • Dosing: many aim for 1–2 g/day EPA+DHA; higher (3 g) cited for triglyceride effects, but commenters stress large inter‑individual variability and unknown “optimal.”
  • Important caution: clinical and anecdotal reports that fish‑oil supplements can worsen mood or trigger mania in some, contra popular “antidepressant” marketing.

Wider nutrition debates

  • Disagreement over dairy’s necessity for bone health; alternatives (beans, leafy greens, fortified foods) listed, and weight‑bearing exercise emphasized as a primary bone determinant.
  • Broader supplement discussion: some only trust modest, replicated benefits for vitamin D (in deficient people), omega‑3, magnesium, and possibly creatine; others warn all four are overstated online.