Ray Peat on Histamine and Allergies

Short answer: Ray Peat did not treat allergy as a fixed trait. He wrote that mast cells release histamine and serotonin under the influence of estrogen and parathyroid hormone, and that allergens get in when stress and low thyroid function have damaged the barriers of the intestine and liver.

What Ray Peat wrote about histamine and allergies

Estrogen makes mast cells release their inflammatory mediators, including histamine and serotonin. Parathyroid hormone does the same. Source: Multiple sclerosis, protein, fats, and progesterone, Milk in context: allergies, ecology, and some myths

Once the barrier functions of the intestine and liver have been damaged, allergens and many other active materials can enter the tissues. Source: Food-junk and some mystery ailments: Fatigue, Alzheimer's, Colitis, Immunodeficiency

Stress is enough to do that damage. It sharply reduces the blood flow to the intestine, and prolonged stress weakens its ability to keep large molecules out. Source: Food-junk and some mystery ailments: Fatigue, Alzheimer's, Colitis, Immunodeficiency

He singled out carrageenan, a thickener in many milk products, as a powerful allergen that has caused colitis and anaphylaxis. People then blame the milk. Source: Food-junk and some mystery ailments: Fatigue, Alzheimer's, Colitis, Immunodeficiency, Milk in context: allergies, ecology, and some myths

The vitamins added to reduced-fat milk, with their carrier and contaminants, are another possible source of reactions, which is why he considered whole milk the least allergenic. Source: Milk in context: allergies, ecology, and some myths

He wrote that calcium carbonate with vitamins D and K can quickly relieve allergies, along with insomnia and inflammation. That fits his point that parathyroid hormone makes mast cells release histamine. Source: Milk in context: allergies, ecology, and some myths

Mast cells are more numerous in the brain in multiple sclerosis, one of several diseases he connected to this system. Source: Multiple sclerosis, protein, fats, and progesterone

What he suggested in practice

• Avoid carrageenan.
• Correct thyroid function and avoid antithyroid substances.
• Enough calcium, with vitamins D and K.
• Protect the bowel: a daily raw carrot and no fermentable fiber.

Where he wrote about it

This topic comes up in 52 of the articles on his site. These are the most relevant ones:

• Autonomic systems · original on raypeat.com ↗
• Milk in context: allergies, ecology, and some myths · original on raypeat.com ↗
• Food-junk and some mystery ailments: Fatigue, Alzheimer's, Colitis, Immunodeficiency · original on raypeat.com ↗
• Multiple sclerosis, protein, fats, and progesterone · original on raypeat.com ↗
• Calcium and Disease: Hypertension, organ calcification, & shock, vs. respiratory energy · original on raypeat.com ↗
• Serotonin, depression, and aggression: The problem of brain energy · original on raypeat.com ↗
• Caffeine: A vitamin-like nutrient, or adaptogen. Questions about tea and coffee, cancer and other degenerative diseases, and the hormones · original on raypeat.com ↗
• Cascara, energy, cancer and the FDA's laxative abuse · original on raypeat.com ↗

My take

Two things decide how easily mast cells dump histamine: carbon dioxide and the inflammatory load from the gut. High CO2 keeps them stable. I used to have allergies and I have none now.

Quick answers

What did Ray Peat say about histamine?

That mast cells release histamine and serotonin under the influence of estrogen and parathyroid hormone, and that these mediators drive inflammation and leaky blood vessels.

What did Ray Peat say causes allergies?

A damaged intestinal and liver barrier, caused by stress, low thyroid function and irritants such as carrageenan, which lets allergens enter the tissues.