Here is where confusion around completely different plants due to the use of common names can have a potentially deleterious effect on human health. The starch, sago, is extracted from a true palm, of the
Metroxylon spp., mainly
Metroxylon sagu and
Metroxylon Rumphii, The piths of the trunks of these palms are high in starch contents. Malaysia is probably the largest producer of this type of starch, most it from the Island of Borneo.
The confusion of this type of true palm with the so called "sago palm" (
Cycas revoluta), which is in fact a cycad, can have deadly consequences, as almost all edible parts of the "false sago palm" are potentially poisonous. Preparation of any material from this plant for use as food or medicine is spefically designed to remove the toxins. The neurotoxins extracted from cycads (possibly BMAA and Cycasin) are linked to a very high incidence of a fatal, paralyzing, neurodegenerative disease amongst the
Chamorro people who live on the West Pacific Island of Guam - amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD) was found to be up to 100 times more common in Guam than in the US and other developed countries. In fact, the disease has been given the name "Guam Disease" (a constellation of neurological signs and symptoms of Alzheimer's, Parkinson's and Motor Neurone Disease).
Following WWII, food was scarce, and there was a heavy reliance by the people of Guam on their natural resources, one of which is starch from the trunks and nuts of the cycads. Intrigueing, the Chamorros also ate fruit bats, which in turn ate the nuts of the cycads, thereby, potentially increasing the toxin load. Epidemiology study relating incidence of the specific neurodegenerative diseases and the distribution of the cycads have strongly suggested a link of these diseases to the cycads.
Moreover, a similar type of neurodengenrative disease has been reported in association with consumption of peas from
Lathyrus sativa in India, in a disease called
Lathyrism. The same toxin, B-methylamino-L-alanine or BMAA, has been isolated from
L. sativa.
The connection between cycads and the neurodegenerative disease has been difficult to establish because the clinical manifestations present ont to two decades following exposure. And the source of exposure can be quite varied, including the use of a chewed up paste from the plant for treating wounds in young children. The long delay in onset of disease from the time of exposure, unfortunately, meant that the use and consumption of products from the cycads was not considered to be a health problem - for a long time (Guam disease was first described in the liiterature in 1936).
If I am not mistaken, I believe there is a UBC connection through this intriguing piece of diagnostic and epidemiological detective work by a number of prominent researchers - through Dr. Christopher Shaw in the Neuroscience programme.
