"Disturbed Serotonin Levels" Theory Disproved
29 March 2006
Sprott: " 29 March 2006
Sprott: "Disturbed Serotonin Levels" Theory For Cot Death (Sids) Already Disproved
Research* published this month in the "Journal of Neuroscience" claiming that disturbed serotonin levels in babies may be linked to cot death (SIDS) is already disproved, says cot death expert Dr Jim Sprott.
A research team headed by physiologist Dr Andrew Tryba (Medical College of Wisconsin) claims that findings relating to serotonin 5-HT2A receptors in mice suggest that if serotonin levels in babies are disturbed, babies may not respond appropriately in situations where they are deprived of oxygen.
"The idea that cot death may be caused by disturbed serotonin levels or faulty serotonin receptors in babies can be refuted in a few sentences," said Dr Sprott. "It is already disproved by well-established cot death epidemiology."
Statistics show that the incidence of cot death rises with birth order: the risk rises from first babies to second babies in families; and from second babies to third babies; and rises again for later babies. Cot death risk is highest among babies of solo parents.
"The rising rate of cot death from one sibling to the next disproves any theory that cot death is linked to disturbed serotonin levels," stated Dr Sprott. "Quite obviously, whether or not babies have disturbed serotonin levels or faulty serotonin receptors is not linked to whether they are first, second or third babies in families, or whether they were born to solo parents."
Dr Sprott states that the rising rate of cot death from one sibling to the next is explained by the toxic gas theory for cot death: Cot death is caused by certain toxic gases generated in mattresses (and other bedding), and the risk of exposure to those gases rises as mattresses are re-used from one baby to the next.**
"Here in New Zealand we've been wrapping babies' mattresses for cot death prevention for eleven years," said Dr Sprott. "Since mattress-wrapping began, the New Zealand nationwide cot death rate is down by 62% and the Pakeha*** ethnic rate is down by about 76%. And there have been no reported cot deaths on wrapped mattresses - regardless of whether the babies had disturbed serotonin levels."
Dr Tryba stated that further research was needed to establish a connection between disturbed serotonin levels and cot death, following which screening of babies for potential risk could be appropriate.
"Both this further research and the screening of babies would be a waste of money," said Dr Sprott. "It is already proved by well-known epidemiology that cot death is not linked to disturbed serotonin levels or faulty serotonin receptors in babies."
* Gasping Activity In Vitro: A Rhythm Dependent on 5-HT2A Receptors, The Journal of Neuroscience 2006;26(10):2623-2634.
** Case-control study of sudden infant death syndrome in Scotland, 1992-5, British Medical Journal 1997;314:1516-20; Used infant mattresses and sudden infant death syndrome in Scotland: case-control study, British Medical Journal 2002;325:1007-1009.
*** Note for overseas readers: "Pakeha" means non-Maori non-Pacific Island. The Pakeha ethnic group comprises 80% of the New Zealand population, and 91% of this group are of European descent.