title: Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca (Lepidium meyenii) in Adult Human Subjects: A Randomized, Double-Blind, Placebo-Controlled Study.
abstract: The plant maca, grown at 4000 m altitude in the Peruvian Central Andes, contains hypocotyls that have been used as food and in traditional medicine for centuries. The aim of this research was to provide results on some health effects of oral administration of spray-dried extracts of black or red maca (Lepidium meyenii) in adult human subjects living at low (LA) and high altitude (HA). A total of 175 participants were given 3 g of either placebo, black, or red maca extract daily for 12 weeks. Primary outcomes were changes in sexual desire, mood, energy, health-related quality of life score (HRQL), and chronic mountain sickness (CMS) score, or in glycaemia, blood pressure, and hemoglobin levels. Secondary outcomes were acceptability and safety, assessed using the Likert test and side effect self-recording, respectively, and the effect of altitude. At low altitude, 32, 30, and 32 participants started the study receiving placebo, red maca, or black maca, respectively. At high altitudes, 33, 35, and 31 participants started the study receiving placebo, red maca, and black maca, respectively. Consumption of spray-dried extracts of red and black maca resulted in improvement in mood, energy, and health status, and reduced CMS score. Fatty acids and macamides were higher in spray-dried extracts of black maca than in red maca. GABA predominated in spray-dried extracts of red maca. Effects on mood, energy, and CMS score were better with red maca. Black maca and, in smaller proportions, red maca reduced hemoglobin levels only in highlanders with abnormally high hemoglobin levels; neither variety of maca reduced hemoglobin levels in lowlanders. Black maca reduced blood glucose levels. Both varieties produced similar responses in mood, and HRQL score. Maca extracts consumed at LA or HA had good acceptability and did not show serious adverse effects. In conclusion, maca extract consumption relative to the placebo improved quality of life parameters. Differences in the level of improvement between red and black maca are probably due to differences in the composition of these two plant varieties. Both maca extracts were well tolerated and safe.
authors.affiliation: Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Lima 31, Peru. carla.gonzales@upch.pe.|Research Circle on Plants with Effects on Health, Lima 15102, Peru. carla.gonzales@upch.pe.|Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru. carla.gonzales@upch.pe.
authors.forename: Carla
authors.initials: C
authors.lastname: Gonzales-Arimborgo
authors.affiliation: Research Circle on Plants with Effects on Health, Lima 15102, Peru. irmaundac@hotmail.com.|Facultad de Enfermeria, Universidad Nacional Daniel Alcides Carrión, Pasco 19001, Peru. irmaundac@hotmail.com.
authors.forename: Irma
authors.initials: I
authors.lastname: Yupanqui
authors.affiliation: Research Circle on Plants with Effects on Health, Lima 15102, Peru. elsamonterojara@hotmail.com.|Facultad de Enfermeria, Universidad Nacional Daniel Alcides Carrión, Pasco 19001, Peru. elsamonterojara@hotmail.com.
authors.forename: Elsa
authors.initials: E
authors.lastname: Montero
authors.affiliation: Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Lima 31, Peru. dulce.alarcon@upch.pe.|Research Circle on Plants with Effects on Health, Lima 15102, Peru. dulce.alarcon@upch.pe.
authors.forename: Dulce E
authors.initials: DE
authors.lastname: Alarcón-Yaquetto
authors.affiliation: Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Lima 31, Peru. alisson.zevallos.c@upch.pe.|Research Circle on Plants with Effects on Health, Lima 15102, Peru. alisson.zevallos.c@upch.pe.
authors.forename: Alisson
authors.initials: A
authors.lastname: Zevallos-Concha
authors.affiliation: Research Circle on Plants with Effects on Health, Lima 15102, Peru. lidia.caballero.g@upch.pe.|Facultad de Nutrición, Universidad Nacional del Altiplano, Puno 21001, Peru. lidia.caballero.g@upch.pe.
authors.forename: Lidia
authors.initials: L
authors.lastname: Caballero
authors.affiliation: Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Lima 31, Peru. manuel.gasco@upch.pe.|Research Circle on Plants with Effects on Health, Lima 15102, Peru. manuel.gasco@upch.pe.|Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru. manuel.gasco@upch.pe.
authors.forename: Manuel
authors.initials: M
authors.lastname: Gasco
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS 38677, USA. jianping@olemiss.edu.
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhao
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, University of Mississippi, Oxford, MS 38677, USA. ikhan@olemiss.edu.
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
authors.affiliation: Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Lima 31, Peru. Gustavo.gonzales@upch.pe.|Research Circle on Plants with Effects on Health, Lima 15102, Peru. Gustavo.gonzales@upch.pe.|Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru. Gustavo.gonzales@upch.pe.
authors.forename: Gustavo F
authors.initials: GF
authors.lastname: Gonzales
keywords: Lepidium meyenii; adverse effects; black maca; botanicals; high altitude; human health; nutraceuticals; placebo; red maca; toxicity