Omega-3 as a Chemo Tool

As season 2 of chemo cycles began, I wanted a tool to help me decide when and what to eat. I built a simple chemo helper to track these foods, supplements, and timing across each cycle. Today, I wanted to learn more about omega-3s from food. What are the benefits of Omega-3s, and why only on certain days?

Why omega-3 matters

Omega-3s (specifically EPA and DHA from food) help during chemo because they address what treatment stresses most after the drugs stop circulating.

Used at the right time, omega-3s:
-- reduce post-chemo inflammation
-- help preserve muscle during recovery
-- support liver recovery while it clears chemo byproducts
-- may improve how residual cancer cells respond to the next cycle
-- help the body transition from “damage mode” to “repair mode.”

The benefit is not about taking omega-3 all the time. It’s about using it after chemo, when inflammation peaks and recovery begins.

When to use omega-3

Focus on omega-3 intake on Days 5–9 of each chemo cycle.

-- Days 1–4: chemo is active, gut and liver are under load
-- Days 5–9: inflammation peaks, recovery starts, food tolerance returns

This window is where omega-3 supports recovery without interfering with treatment.

When not to use omega-3

Do not prioritize omega-3 on:
-- Days 1–4 (pump + crash days)
-- Days when appetite or digestion is unstable

Food Source and Target Dose

1,500–2,500 mg/day of combined EPA + DHA

Salmon (best overall)
EPA+DHA: ~1,200–1,800 mg per 120 g (4 oz)

Plant Sources
These provide ALA, which converts poorly to EPA/DHA (≈5–10%).
-- Flaxseed - ALA: ~2,300 mg per tablespoon
-- Walnuts - ALA: ~2,500 mg per 30 g (handful)
-- Chia - ALA: ~2,300 mg per tablespoon

Daily Omega-3 Templates (Days 5–9)
-- Salmon (120 g) → ~1,500 mg EPA/DHA
-- Walnuts (small handful) → supportive