Omega-3

Omega-3
Molecular formula	Varies (ALA C18H30O2, EPA C20H30O2, DHA C22H32O2)
Type	Polyunsaturated fatty acid class
Saturation	Polyunsaturated (first double bond at carbon 3 from methyl end)
Melting point
Food sources	Flax, chia (ALA); fish oil, algae (EPA/DHA)
Synonyms	n-3 fatty acids
Ray's verdict	Generally hurts Grouped with omega-6 as a stress-promoting, easily oxidized PUFA class, not a cardioprotective essential

Omega-3 fatty acids are polyunsaturated fats with the first double bond at the third carbon from the methyl end: ALA (flax, chia), EPA and DHA (fish oil, algae). Mainstream nutrition treats them as cardioprotective essentials.

Ray Peat grouped omega-3 with PUFA. They oxidize easily, accumulate with age, and amplify stress hormones. See PUFA.

The most highly unsaturated fats, including DHA, accumulate with aging, and their toxic fragments are increased in Alzheimer's disease.

— Ray Peat

The most highly unsaturated fats found in fish oil break down into chemicals that block the use of glucose and oxygen.

— Ray Peat

Omega-3 fats promote metastasis.

— Ray Peat

DHA, transport proteins, and brain lipids

DHA has six double bonds and displaces T4, Estrogen, and Vitamin A from transthyretin and albumin more strongly than linoleic acid in Peat's fats article. A meta-analysis of 4 randomized trials covering 702 Alzheimer's patients found omega-3 supplementation had no significant effect on cognitive function scores versus placebo. DHA alters alpha-synuclein toward Parkinson-linked forms; saturated fats reverse that shift in work he cited.

Women may have higher circulating DHA because estrogen mobilizes unsaturated fats from storage. Brain and retina concentrate highly unsaturated fats, raising peroxidation risk when antioxidant and thyroid support are low.

Animal studies

In 18 pigs split into three groups of 6, each fed a diet with 40% of calories from either palmitic acid, linoleic acid, or fish oil for 21 days, the fish-oil and linoleic-acid diets worsened lung compliance and edema both before and after endotoxin infusion (80 mg/kg/min, raising pulmonary arterial pressure to a trauma-comparable 45-50 mmHg), versus the palmitic-acid diet. Rats without dietary PUFA showed less endotoxin-induced vascular leak than rats on normal chow.

N-3 fats leave the fat droplet first during stress because their saturated carbon tails are shortest and most exposed to lipolytic enzymes.

Dietary guidance

Peat's practical stance is to limit fish-oil megadoses and high-DHA tissue loading, not to treat omega-3 as heart medicine opposite saturated fat. Seafood selenium and whole-food context differ from isolated n-3 pills in his cholesterol writing. See Harm reduction.

See also

• PUFA
• Omega-6
• Lipid peroxidation
• Alzheimer's disease