Obesitat induïda per radiació

Els accidents nuclears de Chernòbil (antiga URRS) i Fukushima (Japó) són de moment els més importants de la història del binomi energia nuclear-humanitat. Diferents en quant a la seva gènesi, ambdós comparteixen el fet d’haver alliberat al medi ambient una ingent quantitat de substàncies radioactives contaminants. En el cas de Fukushima els problemes i la contaminació continuen.

Ara un estudi sobre individus exposats a radiacions moderades de les dues localitats acaba de revelar que existeix un elevat nombre de persones amb obesitat. Aquest increment en la obesitat es deuria a l’efecte de les radiacions sobre una hormona peptídica, secretada pel lòbul intermedi de la glàndula pituitària (en el cervell), anomenada alfa melanòcit estimulant (α-MSH; veure http://es.wikipedia.org/wiki/Lipotropina). Aquesta modificació en la hormona provoca que el mecanisme regulador de la sacietat (mecanisme de control de la gana) quedi malmès i els individus afectats tinguin tendència a engreixar.

L’estudi, realitzat per científics soviètics (del centre nacional per la recerca de la medicina nuclear d’Ucraina), ha servit per fer una comparació amb els nens afectats al Japó i acabar de relacionar la radiació amb l’anomalia de la hormona alfa melanòcit estimulant (veure http://enenews.com/study-fukushima-serious-man-made-disaster-human-history-obesity-rates-double-japan-average-excessive-weight-gain-after-nuclear-disaster-marker-radiation-brain-damage). Dins de l’article veureu que hi ha un interessant poster, en format PDF, que us podeu baixar amb les principals conclusions dels científics soviètics en el cas de Chernòbil.

Study: Fukushima the most serious man made disaster in human history — Obesity rates now nearly double Japan average — Excessive weight gain after nuclear crisis “a marker of radiation brain damage”

 

Published: January 24th, 2015 at 2:12 pm ET
By
Asahi Shimbun, Jan 24, 2015 (emphasis added): Obesity a growing problem among children in Fukushima… An education ministry survey released Jan. 23… found that 15.07 percent of 9-year-olds in Fukushima Prefecture were 20 percent or more heavier than normal. The figure was much higher than the national average of 8.14 percent, and the highest among all 47 prefectures. [It] was also the highest among all prefectures for 7-year-olds, 11-year-olds and 13-year-olds… According to the ministry, obese children are most commonly found in the Tohoku region… the trend has been especially acute in Fukushima Prefecturesince the 2011 onset of the nuclear crisis…. The ministry said this appeared to be because children in Fukushima Prefecture are restricted from playing outdoors due to radiation fears…

National Research Center for Radiation Medicine (Ukraine), 2013: Rise of obesity incidence in ChNPP accident survivors is related to abnormal secretion of α-melanotropin [α-MSH]

  • Accident at the Chernobyl NPP… was followed by the intensive release of a wide range of radioactive elements with affinity to many endocrine tissues. The mentioned radioactive fallout resulted in both internal and external radiation exposure, among others, of the central endocrine structures of the human brain.
  • Higher incidence of borderline obesity – 37%… and of primary obesity – 32.5%… was found in the ChNPP accident survivors vs persons in the control group (31.1 and 24.6% respectively)… For the first time there was revealed a new abnormal way of a reaction on radiation namely – the ‘blunted’ protective response of the physiological increase of α-MSH secretion along with body mass index elevation normally preventing further growth of adipose tissue. There is no increase of α-MSH secretion or even there is a hormone deficiency in most [obese] survivors of the ChNPP accident
  • Received data indicate to the increased risk of borderline obesity and obesity after the prolonged exposure to radiation in moderate doses. The mentioned risk is stipulated by disorders in melanocortin system resulting in α-MSH deficiency at the background of obesity that can be considered as a marker of such an abnormality.

Poster presentation for ‘Rise of obesity incidence in ChNPP accident survivors is related to abnormal secretion of α-melanotropin’ (pdf), 2013:

  • The Chernobyl NPP accident in 1986 and Fukushima NPP accident in 2011 are still the most serious wide scale man made disasters in human history… Massive radioactive release and fallout followed both accidents. Wide range of radioactive isotopes were released some having high affinity to hormone-producing tissues including ones in the cerebral endocrine structures… Today the Chernobyl NPP accident is not over but has evolved into the long-term fourth phase
  • Subjects: The Chernobyl NPP accident survivors (emergency workers… and evacuees…)
  • Decrease of α-MSH… can be considered as a marker of radiation brain damage. Thusα-MSH can be considered as a sensitive marker of radiation impact which deficiency of synthesis leads to disorder of pathways preventing further body mass increase…

α-MSH: Most important of the melanocyte-stimulating hormones in stimulating melanogenesis, a process that… plays a role in feeding behavior… regulation of appetite, metabolism…

See also: Yomiuri: Alarming trend in Fukushima children — Parent’s radiation fears and stress from disaster blamed for spike in obesity rates

 

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