Oysters

Overview

Oysters are bivalve shellfish that provide high levels of zinc, vitamin B12, iron, and selenium, as well as modest amounts of omega-3 fatty acids. Among commonly eaten foods, oysters are notable for their zinc density, supporting enzymes involved in neurotransmitter synthesis, antioxidant defence, and immune function [1]. Their B12 and iron content contribute to red blood cell formation and one-carbon metabolism, which are important for neurological and cardiovascular health.

Within the BRAIN Diet framework, oysters are a strategic micronutrient-dense option where zinc and B12 adequacy are priorities, including some dietary patterns that otherwise use little or no animal foods. Zinc concentrations vary materially by species and environment, but oysters remain among the most zinc-dense commonly eaten foods even with that variability [2].

Key Nutritional Highlights

• Highest selenium among BRAIN Diet fish and seafood pages (per 100 g). [1]
• One of the most zinc-dense commonly consumed foods, with very high vitamin B12 density; zinc levels vary by species and origin. [2]
• EPA and DHA are present, but amounts vary substantially by species and preparation.
• As shellfish, oysters require strict sourcing and handling controls for microbiological safety, especially when consumed raw.

Food Context

Sourcing

• Choose oysters from reputable producers that harvest from monitored coastal waters with active testing for biotoxins and contaminants.
• Farmed oysters typically have a low environmental footprint and can help maintain water quality by filter-feeding, but they should still be sourced from regions with robust safety monitoring.

Preparation

• Oysters can be eaten cooked or, where safe and culturally appropriate, raw; steaming or baking reduces microbiological risk while retaining much of their micronutrient density.
• Pair oysters with vegetable-rich accompaniments such as lemon, herbs, and leafy greens to integrate their concentrated mineral content into balanced meals.

Essential Amino Acid Profile

This food provides a complete essential amino acid profile typical of animal proteins.

Recipes

no recipes found

Nutrient Tables (per 100 g)

Core nutrients

Nutrient	Amount per 100 g	% RDA per 100 g
Energy	51 kcal	—
Protein	5.7 g	—
Total fat	1.7 g	—
Saturated fat	0.5 g	—
Carbohydrates	2.7 g	—
Sugars	0.6 g	—

Key vitamins and minerals

Nutrient	Amount per 100 g	% RDA per 100 g
Iron	4.6 mg	25.6%
Zinc	39.3 mg	357.3%
Selenium	19.7 µg	35.8%
Vitamin B12	8.8 µg	364.6%

Bioactive compounds

Explicitly identified compounds, including individual fatty acids, with a defensible quantity or an explicit qualitative status. Asterisks (*) identify supplementary sources below. Unquantified or trace constituents are not automatically admitted to the Substances list.

Compound / class	Amount per 100 g	Notes
EPA	177 mg	—
DHA	136 mg	—
EPA	876 mg *	Species and cooking method shift long-chain omega-3 totals; values are indicative.
DHA	500 mg *	Often comparable to EPA in Pacific species; check species-specific compositional tables.
Phosphatidylcholine	Present — quantity not established *	—

Source notes (supplementary):

• * EPA: EPA varies widely by species and preparation. USDA FoodData Central for "Mollusks, oyster, Pacific, cooked, moist heat" (FDC 174250; via MyFoodData: https://tools.myfooddata.com/nutrition-facts/174250/wt2) implies ~876 mg EPA per 100 g (0.745 g per 85 g). European flat oysters (Ostrea edulis) in the Danish FRIDA database are lower (~171 mg EPA per 100 g raw; Food ID 163: https://frida.fooddata.dk/food/163). Use as an indicative range.
• * DHA: DHA varies widely by species and preparation. USDA FoodData Central for "Mollusks, oyster, Pacific, cooked, moist heat" (FDC 174250; via MyFoodData: https://tools.myfooddata.com/nutrition-facts/174250/wt2) implies ~500 mg DHA per 100 g (0.425 g per 85 g). European flat oysters (Ostrea edulis) in the Danish FRIDA database are lower (~193 mg DHA per 100 g raw; Food ID 163: https://frida.fooddata.dk/food/163). Use as an indicative range.
• * Phosphatidylcholine: Oysters is a phospholipid-rich food in which phosphatidylcholine is a major choline form; USDA SR Legacy reports choline, not phosphatidylcholine specifically.

Reference intakes: US Dietary Reference Intakes for adults (19–50 years; using the higher of male/female values where they differ).

Data provenance (core / micronutrient panel): USDA FoodData Central, Mollusks, oyster, eastern, wild, raw, FDC ID 171978, SR Legacy bulk (April 2018), per 100 g edible portion, last checked 2026-08-15

Substances

Substances admitted through a supported nutrition-table row. Not every table row appears here. Cards are not BRS mappings.

7 substances in this food

DHA (Docosahexaenoic Acid)

Accounts for ~10–15% of total brain fatty acids, 20–30% of neuronal phospholipids (PE, PS), and >90% of brain omega-3 PUFA; critical for membrane fluidity, synaptic vesicle fusion, neurodevelopment

EPA (Eicosapentaenoic Acid)

Potent anti-inflammatory; precursor to E-series resolvins; modulates dopamine and serotonin signalling

Fe²⁺

Iron

Oxygen transport; dopamine synthesis (tyrosine hydroxylase cofactor)

Phosphatidylcholine (PC)

Key brain phospholipid; carrier for DHA/EPA and acetylcholine precursor pathway

Se^2-

Selenium

Antioxidant enzyme cofactor (GPx); supports redox balance

Vitamin B12 (Cobalamin)

Methylation; myelin; mitochondrial odd-chain FA metabolism

Zn²⁺

Zinc

Cofactor in neurotransmission and antioxidant enzymes; dopamine modulation

References

[1] Among commonly eaten foods, oysters are notable for their zinc density, supporting enzymes involved in neurotransmitter synthesis, antioxidant defence, and immune function. FAO 2013. Dietary protein quality evaluation in human nutrition (DIAAS report)

[2] Zinc concentrations vary materially by species and environment, but oysters remain among the most zinc-dense commonly eaten foods even with that variability. Yang & Li 2024. Understanding the variable metal concentrations in estuarine oysters Crassostrea hongkongensis: A biokinetic analysis