“If red meat has so much iron in it, why don’t cows rust?”

Meat contains iron, called heme iron, that can be readily absorbed. That doesn’t mean that animals are made of iron, but there are jokes.
   
“If red meat has so much iron in it why don’t cows rust? And another thing” was posted on X/Twitter by Eternal Samnation on November 19, 2020, and this received over 2,000 likes. The joke was posted on Bluesky by Eternal Samnation on July 9, 2025.
 
   
American Red Cross
Iron Rich Foods
Food has two types of iron — heme and non-heme iron. Heme iron is found in meat, fish and poultry. It is the form of iron that is most readily absorbed by your body. You absorb up to 30 percent of the heme iron that you consume. Eating meat generally boosts your iron levels far more than eating non-heme iron.
 
Non-heme iron is found in plant-based foods such as fruits, vegetables and nuts. Foods with non-heme iron are still an important part of a nutritious, well-balanced diet, but the iron contained in these foods won’t be absorbed as completely. You absorb between two and 10 percent of the non-heme iron that you consume.
   
X/Twitter
Eternal Samnation
@portmanteauface
If red meat has so much iron in it why don’t cows rust? And another thing
11:09 AM · Nov 19, 2020
 
X/Twitter
CamelCompound
@CamelCompound
If red meat has so much iron in it why don’t cows rust? And another thing like that -
@1BigLiar
2:05 AM · Nov 15, 2023
 
X/Twitter
Binx
@binx1322
If red meat has so much iron in it why don’t cows rust? And another thing
5:27 PM · May 11, 2024
 
X/Twitter
Sibtain_raz1 🇵🇸
@Raz1Sibtain
If red meat has so much iron in it then
why dont cows rust??
1:47 PM · Jul 29, 2024
 
Bluesky
Eternal Samnation
‪@portmanteauface.bsky.social‬
If red meat has so much iron in it why don’t cows rust? And another thing
July 9, 2025 at 6:33 PM