Food supplements for weight loss: questionable efficacy
Abstract
This study aimed to systematically review and analysis of the effects of dietary supplements, in particular L-Carnitine and Conjugated Linoleic Acid (CLA) on thereduction of body fat. We systematically reviewed articles published from 2000 until August 2010. The databases were consulted: PubMed, HighWire, Medline, ScielO and EBSCOhost. For detection of articles, we used the descriptors listed below: Conjugated linoleic acid, L-Carnitine, Supplementation, Weight loss and Obesity. Among the most important findings related to the use of CLA, there is the weight reduction, side effects such as increased insulin resistance, elevated blood glucose and fasting insulin levels, elevated lipid peroxidation and reduced HDL-cholesterol in subjects with metabolic syndrome. For supplementation with L-carnitine, smaller studies had scientific plausibility, since no one could prove the effectiveness of this supplement to reduce body fat. Thus, the recommendation of such supplements with specific purpose of weight loss should be avoided for specific cases and the recommendation should be made cautiously.
References
-Aoki, M.S.; Almeida, A.L.R.A.; Navarro, F.; Rosa, L.F.B.P.C.; Bacurau, R.F.P. Carnitine supplementation fails to maximize fat mass loss induced by endurance training in rats. Annals of Nutrition and Metabolism. Suíca. Vol. 48. Num. 2. 2004. p.90-94.
-Bell, S.J.; Goodrick, G.K. A functional food product for the management of weight. Crit Rev in food Sci Nutr. Vol. 42. Num. 2. 2002. p.163-178.
-Bernardi, F.; Cichelero, C.; Vitolo, M.R. Comportamento de restrição alimentar e obesidade. Rev. Nutr. Campinas. Vol. 18. Num. 1. 2005. p.85-93.
-Blanchard, G.; Paragon, B.M.; Milliat, F.; Lutton, C. Dietary L-carnitine supplementation in obese cats alters carnitine metabolism and decreases ketosis during fasting and induced hepatic lipidosis. J Nutr. Vol. 132. Num. 2. 2002. p. 204-10.
-Botelho, A.P.; Santos-Zago, L.F.; Oliveira, A.C. (in memorian). Effect of conjugated linoleic acid supplementation on lipoprotein lípase activity in 3T3-L1 adipocyte culture. Rev. Nutr. Campinas. Vol. 22. Num. 5. 2009. p. 767-771.
-Brandsch, C.; Eder, K. Effect of L-carnitine on weight loss and body composition of rats fed a hypocaloric diet. Ann-Nutr-Metab. Vol. 46. Num. 52. 2002. p. 05-10.
-Coelho, C.F.; Mota, J.F.; Bragrança, E.; Burini, R.C. Aplicações clínicas da suplementação de L-carnitina. Rev. Nutr. Campinas. Vol. 18. Num. 5. 2005. p. 651-659.
-Coelho, C.F.; Mota, J.F.; Ravagnani, F.C.P.; Burini, R.C. A suplementação de L-carnitina não promove alterações na taxa metabólica de repouso e na utilização dos substratos energéticos em indivíduos ativos. Arq Bras Endocrinol Metab. Vol. 54. Num. 1. 2010. p.37-44.
-Cuppari, L. Guia de nutrição: nutrição clínica no adulto. 2. ed. rev. e ampl. Barueri, São Paulo: Manole, 2005.
-DeLany, J.P.; West, D.B. Changes in Body Composition with Conjugated Linoleic Acid. Journal of the American College of Nutrition. Vol. 19. Num. 4. 2000. p. 487-493.
-Feitoza, A.B.; Fernandes, P.; Costa, N.F.; B. Ribeiro, G.B. Conjugated linoleic acid (CLA): effect modulation of body composition and lipid profile. Nutr Hosp. Rio de Janeiro. Vol. 24. Num. 4. 2009. p. 422-428.
-Gaullier, J.-M.; Halse, J.; Høye, K.; Kristiansen, K.; Fagertun, H.; Vik, H.; Gudmundsen, O. Conjugated linoleic acid supplementation for 1 y reduces body fat mass in healthy overweight humans. Am J Clin Nutr. Vol. 79. 2004. p.1118-25.
-IBGE. Pesquisa de Orçamentos Familiares -POF 2008 2009. Rio de Janeiro: Instituto Brasileiro de Geografia e Estatística -IBGE, 2008-2009. Disponível em: <http://www.ibge.gov.br/home/estatística/população/condicaodevidapof/2008_2009_eneaa/default.shtm>
-Iossa, S.; Mollica, M.P.; Lionetti, L.; Crescenzo, R.; Botta, M.; Barletta, A.; Liverini, G. Acetyl-L-Carnitine Supplementation Differently Influences Nutrient Partitioning, Serum Leptin Concentration and Skeletal Muscle Mitochondrial Respiration in Young and Old Rats. J. Nutrição. Vol. 132. Num. 4. 2002. p. 636-642.
-Makowski, L.; Noland, R.C.; Koves, T.R.; Xing, W.; Ilkayeva, O.R.; Muehlbauer, M.J.; Stevens, R.D.; Muoio, D.M. Metabolic profiling of PPAR mice reveals defects in carnitine and amino acid homeostasis that are partially eversed by oral carnitina supplementation. FASEB J. Vol. 23. 2009. p. 586-604.
-Mattos, R.S.; Luz, M.T. Sobrevivendo ao estigma da gordura: um estudo socioantropológico sobre obesidade. Physis: Revista de Saúde Coletiva. Rio de Janeiro. Vol. 19. Num. 2. 2009. p. 489-507.
-Mourão, D.M.; Monteiro, J.B.R.; Costa, N.M.B.; Stringheta, P.C.; Minim, V.P.R.; Dias, C.M.G.C. Ácido linoléico conjugado e perda de peso. Rev. Nutr. Campinas. Vol. 18. Num. 3. 2005. p. 391-399.
-Patalay, M.; Lofgren, I.E.; Freake, H.C.; Koo, S.I.; Fernandez, M.L. The lowering of plasma lipids following a weight reduction program is related to increased expressionof the ldl receptor and lipoprotein lipase. J. Nutr. Vol. 135. 2005. p. 735-739.
-Pinheiro, A.R.O.; Freitas, S.F.T.; Corso, A.C.T. Uma abordagem epidemiológica da obesidade. Rev. Nutr. Campinas. Vol. 17. Num. 4. 2004. p. 523-533.
-Reis Filho, A.D.; Silva, M.L.S.; Fett, C.A.; Lima, W.P. Efeitos do treinamento em circuito ou caminhada após oito semanas de intervenção na composição corporal e aptidão física de mulheres obesas sedentárias. Revista Brasileira de Obesidade, Nutrição e Emagrecimento. São Paulo. Vol. 2. Num. 11. 2008. p. 498-507.
-Risérus, U.; Smedman, A.; Basu, S.; Vessby, B. Metabolic effects of conjugated linoleic acid in humans: the Swedish experience. Am J Clin Nutr. Vol. 79. 2004. p. 1146S-1148S.
-Scheneider, A.P. Nutrição estética. 1ed. São Paulo: Atheneu, 2009.
-Smedman, A.; Vessby, B. Conjugated linoleic acid supplementation in humans: metabolic effects. Lipids. Vol. 36. 2001. p. 773-781.
-Terpstra, A.H.M.; Beynen, A.C.; Everts, H.; Kocsis, S.; Katan, M.B.; Zock, P.L. The Decrease in Body Fat in Mice Fed Conjugated Linoleic Acid Is Due to Increases in Energy Expenditure and Energy Loss in the Excreta1. J. Nutrição. Vol. 132. Num. 5. 2002. p. 940-945.
-Thom, E.; Wadstein, J.; Gudmundsen, O. Conjugated linoleic acid reduces body fat in healthy exercising humans. The Journal of International Medical Research. Vol. 29. 2001. p. 392-396.
-Tsuboyama-Kasaoka, N.; Takahashi, M.; Tanemura, K.; Kim, H.-J.; Tange, T.; Okuyama, H.; Kasai, M.; Ikemoto, S.; Ezaki, O. Conjugated linoleic acid supplementation reduces adipose tissue by apoptosis and develops lipodystrophy in mice. Diabetes. Vol. 49. 2000. p. 1534-1542.
-Villani, R.G.; Gannon, J.; Self, M.; Rich, P.A. L-Carnitine supplementation combined with aerobic training does not promote weight loss in moderately obese women. Sport Nutr Exerc Metab. Vol. 10. Num. 2. 2000. p. 199-207.
-Wanderley, E.N.; Ferreira, V.A. Obesidade: uma perspectiva plural. Ciência & Saúde Coletiva. Vol. 15. Num. 1. 2010. p.185-194.
-Wang, Y.; Jones, P.J.H. Dietary conjugated linoleic acid and body composition. Am J Clin Nutr. Vol. 79. 2004. p. 1153-1158.
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