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The Balance of Health

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Cow's milk vs oat milk

A like-for-like swap in tea, coffee and cereal. Oat milk has far lower environmental impact but also much less protein.

Sample data. The figures and sources on this page are demonstration records showing how evidence will be presented. They are approximate and have not yet been through our review process. Read about how we will verify evidence.

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Same amount of protein from each food. Fairer for protein foods. That is 2,941 g of cow's milk against 10,000 g of oat milk.

Greenhouse gas emissions

kg CO₂e per 100 g protein

Cow's milk and Oat milk are about the same.

All greenhouse gases released producing the food, from land clearing to retail, expressed as carbon dioxide equivalents.

Oat milk: Global average

Land use

m² per 100 g protein

Cow's milk has about 3.3 times the land of Oat milk, so Oat milk has the lower impact here.

Farmland needed to produce the food, including grazing and land for animal feed.

Water pollution (eutrophication)

g PO₄e per 100 g protein

Cow's milk has about 2.0 times the pollution of Oat milk, so Oat milk has the lower impact here.

Nutrient run-off from fertiliser and manure that causes algal blooms and dead zones, in phosphate equivalents.

Protein

g per 100 g protein

Cow's milk and Oat milk are about the same.

Protein content of the food as eaten.

Fibre

g per 100 g protein

Oat milk contains fibre; Cow's milk contains none.

Dietary fibre. Animal foods contain none.

Saturated fat

g per 100 g protein

Cow's milk has about 3.4 times the sat. fat of Oat milk, so Oat milk has the lower impact here.

Saturated fat content. Higher intakes raise LDL cholesterol.

Animals slaughtered

animals per 100 g protein

Neither involves slaughtered animals.

Approximate number of animals slaughtered for this amount of food. Small fractions mean one animal yields many portions. Zero for plant foods; dairy and eggs involve animals indirectly.

Sample data
Methodology, sources and caveats
  • Environmental values are averages per kilogram of food as eaten, converted to the basis you choose. Farms vary widely around these averages; thin lines on the bars show the reported range where the source gives one.
  • Where a food has figures for more than one country or production system, the default is the all-systems figure for your country (or the global average). The figure menu under a chart lets you choose another; the source and geography update with it.
  • Nutrient values are reference composition figures. Preparation and variety change them, and absorption differs between plant and animal sources (see the nutrient panel).
  • No single metric tells the whole story. A food can score well on emissions and poorly on water, or well on protein and poorly on fibre.
  • Freshwater use: Water use matters mainly where water is scarce. A litre in a rainy region is not equivalent to a litre in a drought-prone one, so treat this as indicative only.
  • Scarcity-weighted water use: Scarcity weighting depends on where each food is actually grown. Global figures blend many regions; country figures are shown where a source provides them.
  • Animals slaughtered: Dairy and eggs are shown as zero because no animal is slaughtered per unit sold, but both systems involve animals; this metric only counts direct slaughter.
  • Oat milk: Calcium figure assumes a fortified product; unfortified oat milk contains little calcium and no B12.

Sources: Poore et al. (2018); Service (2024); Nations (2024). See how we rate evidence.

In short, per 100 g of protein

  • Cow's milk and Oat milk are about the same.
  • Cow's milk has about 3.3 times the land of Oat milk, so Oat milk has the lower impact here.
  • Cow's milk has about 2.0 times the pollution of Oat milk, so Oat milk has the lower impact here.
  • Cow's milk and Oat milk are about the same.
  • Oat milk contains fibre; Cow's milk contains none.
  • Cow's milk has about 3.4 times the sat. fat of Oat milk, so Oat milk has the lower impact here.
  • Neither involves slaughtered animals.

Change the basis above to see how the picture shifts by serving, weight or calorie. Build your own comparison in the full tool.