Why in news?
Researchers at the All India Institute of Medical Sciences (AIIMS), Bhubaneswar, are investigating whether the seeds of cycad plants contain a neurotoxin called BMAA (β‑Methylamino‑L‑alanine). The study, prompted by neurological disorders reported among tribal communities using cycad seeds as food, aims to assess any link between the toxin and diseases such as amyotrophic lateral sclerosis (ALS).
Background
Cycads are a group of ancient seed plants that have existed since the age of dinosaurs. Though their stiff, feather‑like leaves make them resemble palms, cycads are gymnosperms more closely related to conifers. A typical cycad has a thick, often unbranched trunk topped with a crown of pinnate leaves. Male and female cones grow on separate plants – the male cones produce pollen while the female cones bear ovules which develop into seeds.
Cycads grow slowly and are popular as ornamental plants in gardens. Some species yield a starchy substance known as sago. Indigenous peoples in parts of Asia and the Pacific remove natural toxins from cycad seeds by repeated washing and cooking to produce flour. Without proper preparation the seeds contain toxic compounds, including cycasin and BMAA, that can damage the liver or nervous system. In Guam, excessive consumption of cycad flour has been linked to a high incidence of neurodegenerative illness.
Toxicity and uses
- BMAA neurotoxin: Cycad roots host cyanobacteria that can produce BMAA. When seeds or flour are consumed, the toxin may enter the human food chain and has been associated with motor neuron diseases in some communities.
- Edible starch: After thorough detoxification, some cycad species provide sago used to make porridge and baked products. In India the young fronds are sometimes eaten as a vegetable after boiling.
- Ornamental value: Their symmetrical crowns and tolerance for drought make cycads popular in landscaping. Species such as the sago palm (Cycas revoluta) are cultivated around the world.
- Conservation concern: Slow growth and habitat loss have made many cycad species endangered. International trade in wild plants is regulated by the Convention on International Trade in Endangered Species (CITES).
Research significance
The AIIMS study will measure BMAA concentrations in locally consumed cycad varieties and examine patients’ diets and medical histories. Understanding the toxicity levels could help health authorities advise communities on safe preparation methods or alternative foods. More broadly, the work highlights the need to investigate traditional diets and environmental factors behind neurological diseases.
Source: Times of India, Britannica – Cycads