Why can the cause of food allergies and elevated histamine not be food?

Modern research indicates that histamine production in the body is not only an allergic reaction to food or external irritants but also a neurohumoral response to internal homeostatic disturbances, including dehydration.

How water is related to histamine

Histamine is a biogenic amine compound that performs multiple functions:

• neurotransmitter in the central nervous system;
• mediator of inflammation;
• regulator of vascular tone, capillary permeability, and gastric juice secretion.

When the brain senses a deficiency of water, it can activate the histaminergic system as a protective mechanism.

Why the brain activates histamine during dehydration:

The role of histamine as a signaling molecule. When water is scarce, the brain increases histamine production to:

• limit water intake to non-vital organs;
• redistribute fluid in favor of vital organs (brain, heart);
• constrict peripheral vessels to prevent moisture loss through the skin;
• stimulate the release of stress hormones (cortisol, vasopressin) to retain water in the body.

Histamine as a thirst hormone. Scientists, such as Dr. Batmanghelidj, have pointed out that histamine may be part of the thirst signaling system: if you do not drink enough water, the brain increases histamine levels, which can manifest not only as dry mouth but also as allergy-like symptoms—swelling, headaches, skin rashes, irritability.

Practical conclusions

• People suffering from "food allergies" or "histamine intolerance" may actually have chronic dehydration, where histamine levels rise as a compensatory mechanism.
• Adequate drinking behavior (30–40 ml of water per 1 kg of body weight) can significantly reduce the activity of the histaminergic system, especially if the diet contains enough salt necessary for retaining water in the intercellular space.

This explains why some people experience relief from skin or respiratory symptoms after simply increasing their water intake.