Understanding Lathyrism: The Disease Caused by Kesari Dal

January 2, 2026 •

3 min read

Historically documented in famines as far back as 400 BC, the serious medical condition caused by Kesari dal is a neurodegenerative disorder known as lathyrism. This disease is triggered by a neurotoxin found in the pulse, which, upon prolonged and excessive consumption, can cause severe, irreversible paralysis of the lower limbs.

Quick Summary

Prolonged, excessive consumption of Kesari dal, or grass pea, causes lathyrism, a neurodegenerative disorder resulting in irreversible paralysis of the legs due to the neurotoxin β-ODAP.

Key Points

Lathyrism is a neurological disease: Prolonged, excessive consumption of Kesari dal causes neurolathyrism, an irreversible neurological disorder affecting the spinal cord.
The cause is a neurotoxin: The pulse contains β-ODAP, a neurotoxic amino acid that overstimulates neurons, leading to cellular damage and death.
Paralysis is the primary symptom: The toxin's effect on motor neurons results in progressive spasticity and irreversible paralysis of the legs.
Risk increases with heavy consumption: The risk is highest for individuals consuming Kesari dal as a dietary staple, especially during famines when it constitutes over 30% of their intake.
Prevention is crucial: Methods like soaking, boiling, mixing with other cereals, and developing low-toxin varieties are essential for preventing the disease.

What is Neurolathyrism and its Cause?

Neurolathyrism is the specific type of lathyrism associated with the consumption of legumes from the genus Lathyrus, primarily Lathyrus sativus, known commonly as Kesari dal, grass pea, or chickling pea. It is an irreversible neurological disease affecting populations who rely on this hardy crop as a dietary staple, often during food insecurity. The condition is caused by the neurotoxic amino acid β-N-oxalyl-L-α,β-diaminopropionic acid, or β-ODAP.

The Mechanism of the β-ODAP Toxin

When ingested in large quantities over time, β-ODAP acts as an excitotoxin in the central nervous system, mimicking glutamate and overstimulating neuronal receptors. This leads to excessive excitation and cellular damage or death, specifically affecting upper motor neurons and pyramidal tracts in the spinal cord responsible for lower limb movement. The outcome is a progressive loss of motor function, leading to spastic paralysis. β-ODAP also impairs mitochondrial function and increases oxidative stress, contributing to nerve cell degeneration.

Symptoms and Progression of Neurolathyrism

Lathyrism develops gradually after chronic high-level consumption, with symptoms progressing from subtle signs to severe disability.

Stages of Lathyrism

Early warning signs: Mild leg weakness, muscle cramps (especially in calves after exertion), and a sensation of heaviness.
Progressive development: Increased muscle stiffness (spasticity), making movement difficult. A characteristic "scissor gait" develops. Lower limb reflexes become exaggerated.
Advanced lathyrism: Severe paralysis in lower limbs (paraparesis or paraplegia) requiring assistive devices or preventing walking. Muscle wasting (atrophy) and joint contractures may occur. Sensation, mental function, and upper limb movement are typically unaffected.

Risk Factors and Prevention

The main risk is prolonged, heavy consumption of Kesari dal, particularly over 30% of the daily diet, often occurring in drought or famine-stricken areas. Malnutrition can worsen risk. Young adult males may be more susceptible due to higher consumption and exertion.

Methods to Reduce Toxicity

Proper preparation: Soaking overnight and rinsing can significantly reduce β-ODAP content. Boiling and discarding the water also helps.
Dietary diversification: Mixing Kesari dal with other foods, especially cereals rich in sulfur-based amino acids, is highly effective.
Low-toxin varieties: Cultivating and using low-toxin strains of Lathyrus sativus is a long-term solution.
Public awareness: Educating communities on risks and safe preparation is vital.

Neurolathyrism vs. Osteolathyrism

These are distinct conditions caused by different Lathyrus legumes and toxins, affecting different systems.


Feature	Neurolathyrism	Osteolathyrism
Cause	Lathyrus sativus (Kesari dal).	Lathyrus odoratus (sweet peas).
Toxin	β-ODAP.	Beta-aminopropionitrile (BAPN).
System Affected	Central nervous system, motor neurons.	Connective tissues (bones, blood vessels).
Symptoms	Progressive, irreversible lower limb paralysis, spasticity.	Skeletal deformities, hernias, aortic aneurysms.

The Path Forward

Neurological damage from advanced neurolathyrism is irreversible. Treatment is supportive, focusing on physical therapy and assistive devices. Stopping Kesari dal consumption is crucial to prevent worsening.

Public health initiatives, improved food security, and developing low-toxin varieties are essential for prevention. The situation highlights the challenge of balancing the need for resilient food sources with health risks. Research institutions like the National Institutes of Health continue to investigate this disease.

Conclusion

In conclusion, the disease caused by Kesari dal is lathyrism, a neurodegenerative disorder causing irreversible lower limb paralysis due to the neurotoxin β-ODAP. It primarily affects vulnerable populations relying on the pulse during scarcity. Prevention through proper cooking, dietary diversity, and public awareness is critical, as advanced lathyrism is irreversible, though discontinuing consumption can halt progression.

Frequently Asked Questions

The neurotoxic amino acid in Kesari dal that causes lathyrism is called β-N-oxalyl-L-α,β-diaminopropionic acid, or β-ODAP.

To eat Kesari dal safely, it should be soaked overnight and boiled, with the water being discarded to leach out toxins. It is also crucial to consume it in moderation and mix it with other cereals to avoid making it a dietary staple.

No, once the neurological damage occurs from lathyrism, it is considered irreversible and there is no cure. Treatment focuses on managing symptoms and preventing further progression by stopping consumption.

Populations facing famine, drought, or extreme poverty who rely heavily on Kesari dal as a primary food source are most at risk. Young men engaged in heavy physical labor may also be more susceptible.

Proper cooking methods like soaking and boiling can significantly reduce the concentration of the water-soluble toxin β-ODAP, but they do not eliminate it completely.

Neurolathyrism primarily causes progressive paralysis of the lower limbs. While advanced cases can impact motor function more broadly, it typically leaves sensation and mental function intact.

Yes, scientists have developed low-toxin varieties of Kesari dal through selective breeding and genetic approaches to maintain the crop's hardiness while reducing health risks.