Why can't rats eat tomatoes? - briefly
Rats are vulnerable to solanine, a toxic alkaloid concentrated in unripe tomatoes and their green stems, which can induce severe neurological effects. Consequently, ingestion of tomato foliage or underripe fruit can be fatal for the animal.
Why can't rats eat tomatoes? - in detail
Rats experience digestive distress when they ingest tomato fruit because the plant contains several compounds that interfere with rodent physiology.
Tomato tissues are rich in solanine and tomatine, glycoalkaloid substances that act as natural deterrents against herbivores. In rodents, these chemicals bind to cell membranes in the gastrointestinal tract, increasing permeability and provoking inflammation. The resulting irritation can lead to vomiting, diarrhea, and loss of appetite.
Additionally, the acidic pH of ripe tomatoes (approximately 4.0–4.5) exacerbates gastric irritation. Rats possess a comparatively sensitive stomach lining; exposure to high acidity accelerates ulcer formation and impairs nutrient absorption.
A secondary factor involves the high concentration of oxalic acid in tomato leaves and stems. When rats chew on foliage, oxalates precipitate calcium, forming calcium oxalate crystals that damage renal tissue. Chronic exposure may cause kidney stones and reduced renal function.
Key points summarizing the physiological barriers:
- Glycoalkaloids (solanine, tomatine) → membrane disruption, inflammation.
- Low pH of fruit flesh → gastric ulceration, impaired digestion.
- Oxalic acid in vegetative parts → calcium oxalate crystal formation, renal injury.
Laboratory observations demonstrate that rats offered tomato puree exhibit a marked decrease in feed intake within 24 hours, accompanied by elevated blood markers of inflammation. Conversely, removal of glycoalkaloids through selective breeding or processing reduces adverse effects, indicating the primary role of these compounds.
In conclusion, the combination of toxic glycoalkaloids, high acidity, and oxalic acid renders tomato consumption hazardous for rats, leading to gastrointestinal and renal complications that discourage natural feeding on this fruit.