Two days of oatmeal reduce cholesterol level

Original Article ↗ Hacker News Discussion ↗

Study novelty and design

  • Commenters note it’s long known that oats lower cholesterol; the new aspect is a 2‑day, high‑dose protocol (300 g rolled oats/day, 3 x 100 g meals) that changes the gut microbiome and keeps LDL lower for weeks.
  • The paper compares:
    • 2 days of high‑dose oats vs. calorie‑matched non‑oat control meals.
    • 6 weeks of one oat meal/day vs. habitual diet without oats.
  • The intensive 2‑day “oats only” phase (with some fruits/vegetables allowed) produced ~10% LDL reduction and effects persisting through a 6‑week oat‑free follow‑up.

Dose, duration, and practicality

  • 300 g dry oats/day is described as “a lot”: roughly 3+ typical servings, ~1000–1200 kcal if plain.
  • It is emphasized this is not a long‑term diet but a brief intervention, possibly repeatable (e.g., “two days a month” suggested, but untested).

Diet vs medication for cholesterol

  • Some see a 10% LDL drop from a restrictive diet as modest compared with large reductions achievable by combinations of statins, ezetimibe, and PCSK9 inhibitors.
  • Others push back that the 85–95% figures quoted are for aggressive combination therapy, not typical monotherapy.
  • There’s debate over whether dietary fiber/bile‑acid sequestrants should be first‑line vs. “bazooka” systemic drugs; replies argue medications are more potent and easier to standardize, with lifestyle changes used in parallel or afterward.

Proposed mechanisms

  • Main candidates discussed:
    • Soluble fiber (β‑glucan) capturing bile acids, increasing cholesterol excretion and hepatic LDL uptake.
    • Microbiome shifts producing phenolic compounds that affect lipid metabolism.
    • Calorie restriction and weight/glycogen loss as a confounder, partly controlled by a calorie‑matched non‑oat group.
  • Some commenters propose pairing oats with fat to trigger more bile release; others highlight that fiber effects and enterohepatic circulation are more complex and partly disputed in the thread.

Fiber, alternative foods, and individual response

  • Several note that other high‑fiber foods (barley, legumes, soybeans, psyllium) also lower LDL; one wonders if similar high‑dose “shock” protocols with other grains/legumes would work as well.
  • Some report dramatic LDL drops and better satiety/digestion after adding oat‑based meals; others see significant glucose spikes from oatmeal on continuous glucose monitors and prefer different fibers.

Preparation, taste, and glycemic effects

  • Extensive discussion of rolled vs. steel‑cut oats, cooking vs. soaking, microwave vs. rice cooker/pressure cooker, sweet vs. savory additions, and efforts to avoid added sugar.
  • Debates about glycemic index: oatmeal can spike glucose for some, but combining with fats, protein, and seeds appears to blunt spikes in at least one CGM anecdote.

Skepticism, funding, and clinical framing

  • Some express suspicion because cereal industry groups co‑funded the trial; others counter that weight loss and water shifts can explain the 2 kg loss in 2 days and that the control arm limits pure calorie‑deficit explanations.
  • One perspective is that the real value is a simple, cheap, 2‑day intervention clinicians can prescribe to metabolic‑syndrome patients to quickly improve lipids and possibly motivate further care.