L'arnaque des compléments alimentaires

LE MONDE

Ils envahissent les vitrines et les rayons des pharmacies. Ils promettent de "réduire le tour de taille", de "déstocker les graisses" ou bien de "ralentir le vieillissement", ou encore de "fortifier les ongles et les cheveux". Sous forme de gélules, comprimés ou ampoules, les compléments alimentaires, également vendus en grandes surfaces et sur Internet, ont représenté, en 2005, un marché florissant de 894 millions d'euros, en hausse de 7 % par rapport à 2004. "Un marché de la poudre aux yeux et des pilules pipeau", a dénoncé, mercredi 21 février, l'association de consommateurs Consommation, logement et cadre de vie (CLCV).

Après avoir comparé les promesses de 140 produits aux publications scientifiques référencées par le National Institute of Health, principale agence de recherche médicale américaine, et aux avis publiés par les agences sanitaires, la CLCV affirme aboutir à un résultat sans appel : "Les vertus des compléments alimentaires relèvent pour l'essentiel de l'affabulation."

Caféine, extrait de thé vert, acide linoléique conjugué ou chitosan : aucune de ces substances - très souvent rencontrées dans la composition des produits "minceur" - "n'a fait la preuve de son efficacité", souligne la CLCV. Idem pour l'huile de bourrache ou d'onagre contenue dans la plupart des produits censés améliorer "la santé de la peau" ou les apports en silicium promettant des cheveux "plus forts et plus sains". L'Agence française de sécurité sanitaire des aliments (Afssa) et la direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF) ne contestent pas l'enquête menée par la CLCV.

EXPLOSION DU MARCHÉ

Parce qu'ils dépendent du code de la consommation et non de celui de la santé publique, les compléments alimentaires n'ont pas besoin, contrairement aux médicaments, d'une autorisation de mise sur le marché (AMM). "Le biais est là", considère le professeur Irène Margaritis, chef de l'unité évaluation nutrition et risques nutritionnels à l'Afssa.

Résultat : les contrôles, menés par la DGCCRF, ne peuvent s'effectuer qu'après la commercialisation et porte essentiellement sur l'étiquetage pour vérifier que les allégations ne sont pas thérapeutiques. "Un complément alimentaire ne peut pas dire qu'il va prévenir telle ou telle maladie ou permettre une perte de poids", explique-t-on à la DGCCRF. En revanche, il peut tout à fait alléguer une "réduction du tour de taille". Les services de marketing ne s'y sont pas trompés et débordent de créativité pour contourner la réglementation.

L'Afssa ne peut travailler sur ces produits que si elle est saisie par la DGCCRF. Preuve de l'explosion du marché, le nombre de saisines est passé de 50 en 2000 à 100 en 2005. "Nous menons une évaluation à partir des connaissances scientifiques et des études cliniques fournies par les entreprises", explique le professeur Margaritis. Mais les preuves des allégations font souvent défaut. "Nous manquons beaucoup d'études cliniques bien menées, notamment dans le domaine de la minceur", déplore-t-elle. Ces dernières années, l'Afssa a rendu une série d'avis défavorables, notamment sur l'utilisation de la poudre de maca et sur la supplémentation en silicium. Après, c'est à la DGCCRF de contrôler la bonne application des avis de l'Afssa.

Il peut arriver que des allégations soient fondées scientifiquement mais qu'elles concernent une cible particulière et non la population en général. Il en est ainsi des suppléments en vitamines B9 pour les femmes enceintes ou en vitamines B12 réservés aux personnes âgées. "La question de la cible est très importante, insiste Mme Margaritis. Si notre alimentation est équilibrée et diversifiée, nous n'avons pas besoin de suppléments."

Afssa : www.afssa.fr

Sandrine Blanchard

Out-of-body Experiences May Be Caused by Arousal System Disturbances in Brain

BJS

Having an out-of-body experience may seem far-fetched to some, but for those with arousal system disturbances in their brains, it may not be a far off idea that they could sense they were really outside their own body watching themselves. In previous studies of more than 13,000 Europeans, almost 6 percent said they have had such an out-of-body experience.

Dr. Kevin Nelson and a research team at the University of Kentucky have studied the link between out-of-body experiences, the sleep-wake transition and near death experiences, and published their findings today in the March 6 issue of the journal Neurology in their case report, "Out-of-body experience and arousal."

The results are intriguing, and show that some people's brains already may be predisposed to these sorts of experiences. They found that an out-of-body experience is statistically as likely to occur during a near death experience as it is to occur during the transition between wakefulness and sleep. Nelson suggests that phenomena in the brain's arousal system, which regulates different states of consciousness including REM sleep and wakefulness, may be the cause for these types of out-of-body displays.

"We found it surprising that out-of-body experience with sleep transition seemed very much like out-of-body experience during near death," Nelson said.

For their study, the team conducted structured interviews with 55 people who have had a near death experience. They found those who had an out-of-body experience along with near death were more likely to also have had some sort of REM intrusion in their lifetime, where instead of passing directly between the REM sleep state and wakefulness, the brain switch blends these states into one another.

To survey out-of-body experiences that occurred during sleep transition, patients were asked, "Just before falling asleep or just after awakening, have you had the sense that you are outside of your body and watching yourself?" A similar question was posed to survey out-of-body experiences during near death, which asked subjects if during their experience they had "clearly left the body and existed outside it."

Because the arousal system controls or influences sleep-wake states, alertness and attention, Nelson and the research team questioned whether people with near death experiences may already have an arousal system predisposed to allowing intrusion of REM sleep elements during the transition between wakefulness and sleep.

Sleep paralysis is a common form of REM intrusion, which can cause a condition of temporary paralysis along with visual or auditory hallucinations immediately after waking up or before falling asleep due to an ill-timed disconnection between the brain and the body. Although it was once considered very rare, about 25 percent of all people have probably experienced sleep paralysis sometime during their life.

During a medical crisis, Nelson said muscle paralysis combined with an out-of-body experience could show many of the same prominent features of a near death experience. Near death experiences are responses to a life-threatening crisis, and are characterized by a combination of disassociation from the physical body, euphoria and transcendental or mystical elements.

This investigation supports the notion of out-of-body experiences as an expression of arousal in near death experiences and sleep paralysis. Almost all of the near death subjects having sleep paralysis, 96 percent, also had an out-of-body experience either during sleep transition or near death.

"The strong association of sleep paralysis with out-of-body experiences in the near death experience subject is curious and unexplained," Nelson said. "However, persons with near death experiences appear to have an arousal system predisposed to both REM intrusion and out-of-body experiences."

Nelson is a professor of neurology at the UK College of Medicine and a UK HealthCare physician at the Kentucky Neuroscience Institute. Other team members are Michelle Mattingly, assistant professor of neurology, and Frederick A. Schmitt, professor of neurology, both at the UK College of Medicine.

The full case report can be read online in the March 6 issue of Neurology.

From University of Kentucky