Brain & Cognition
Maca has been studied for its effects on mood and depression, energy, and menopausal symptoms, which, in part, can include aspects of brain health. Neuroprotective activity of maca has been studied in vivo and in vitro (1), however this section primarily focuses on the limited number of studies specific to memory and learning. Maca’s positive impact on memory and learning may be due, in part, to the phytochemical compounds found in various levels, depending on the phenotype.
Macamides, one phytochemical found in maca, have been proposed as a potential therapy for neurological disorders due to the low toxicity, neuroprotective, immune-enhancing, anti-inflammatory, and antioxidant properties (2). In part, macamides provide neuroprotection by activating the Nrf2/HO-1 signaling pathway, resulting in improved synaptic plasticity and by modulating the gut microbiota (3). Macamides from maca extracts have been found to provide superior neuroprotective activity against PC12 cell injury* as compared to a drug therapy (nimodipine), along with higher nitric oxide (NO) inhibition, resulting in a greater anti-inflammatory response (4).
The polysaccharides are noted to promote proliferation, enhance phagocytosis, increased nitric oxide production, and is considered a powerful free radical scavenger, with “enormous potential” for various neurologic clinical applications (1).
Animal Studies
One mouse model compared the effects of four doses of a hydroalcoholic extract of black maca (0.125, 0.25, 0.50, and 1.0 g/kg of body weight) to assess the impact on memory impairment caused by ethanol. The mice treated with black maca reversed the deleterious effects of ethanol in a dose-dependent manner, with the authors suggesting this effect may be due to the polyphenolic compounds (quercetin and anthocyanins) found in black maca (5).
A couple of animal studies have explored black maca’s effects on memory, specifically due to its antioxidant content and ability to inhibit acetylcholinesterase. In ovariectomized mice, an aqueous extract of black maca (Peru-sourced) improved memory (6). Another study used two different doses of aqueous (0.50 and 2.00 g/kg) and hydroalcoholic (0.25 and 1.00 g/kg) extracts of black maca in male mice and found all doses and both extracts improved memory (7). Tarabasz et al. identified that glucosinolates in Lepidium peruvianum could inhibit acetylcholinesterase and butyrylcholinesterase, making this a possible treatment consideration for memory-enhancing benefits (8).
In one study exploring three colors (yellow, black, and red) of maca for depression, memory, and learning, all three colors provided anti-depressant effects. However, black maca provided the most beneficial effects on latent learning (water-finding task), particularly on trained mice, though all three phenotypes were effective for trained and non-trained mice (9). Red maca (2.0 g/kg body weight) has been shown to increase the ability of learning and memory in ovariectomized rats in a similar fashion to estradiol (10).
An unspecified color of maca was found to improve cognitive functions, including memory retention and motor coordination, and significantly increase oxidative phosphorylation enzyme complexes, suggesting an improvement in mitochondrial function in middle-aged mice (11).
For the first time, a study published in 2023 found that the oral administration of an aqueous black maca extract improved cognitive function, spatial memory, social acquisition, recognition, and neuronal activation in an animal model of autism spectrum disorder, suggesting additional research should be conducted to assess black maca’s effect on social deficits in individuals with ASD (12).
Human Studies
At present, human studies are lacking regarding the benefits of maca, specifically for memory and learning, though some studies show positive impacts on energy and mood, including depression and anxiety.
*PC12 cells are used in neuroscience research to study neurotoxicity, neuroprotection, neuronal differentiation, neurosecretion, neuroinflammation, and synaptogenesis.
Author: Kim Ross, DCN
Reviewer: Deanna Minich, PhD
Last Updated: December 17, 2024
References
1. Malík M, Tlustoš P. Nootropic Herbs, Shrubs, and Trees as Potential Cognitive Enhancers. Plants (Basel). 2023 Mar 18;12(6).
2. Vera-López KJ, Davila-Del-Carpio G, Nieto-Montesinos R. Macamides as Potential Therapeutic Agents in Neurological Disorders. Neurol Int. 2024 Nov 21;16(6):1611–25.
3. Xia N, Xu L, Huang M, Xu D, Li Y, Wu H, et al. Neuroprotection of macamide in a mouse model of Alzheimer’s disease involves Nrf2 signaling pathway and gut microbiota. Eur J Pharmacol. 2024 Jul 15;975:176638.
4. Li K, Li Z, Men L, Li J, Gong X. Deep Eutectic Solvent-Based Ultrasound-Assisted Strategy for Simultaneous Extraction of Five Macamides from Lepidium meyenii Walp and In Vitro Bioactivities. Foods. 2023 Jan 5;12(2).
5. J. R, S. Y, M. G, G.F. G. Dose response effect of black maca (Lepidium meyenii) in mice with memory impairment induced by ethanol. Vol. 21, Toxicology Mechanisms and Methods. 2011.
6. Liu X, Rubio J, Qiong W, Jiang Z, Dang H, Chen SL, et al. Aqueous extract of black maca (Lepidium meyenii) on memory impairment induced by ovariectomy in mice. Evidence-based Complementary and Alternative Medicine. 2011;2011.
7. Rubio J, Dang H, Gong M, Liu X, Chen S lin, Gonzales GF. Aqueous and hydroalcoholic extracts of Black Maca (Lepidium meyenii) improve scopolamine-induced memory impairment in mice. Food and Chemical Toxicology. 2007;45(10).
8. Tarabasz D, Szczeblewski P, Laskowski T, Płaziński W, Baranowska-Wójcik E, Szwajgier D, et al. The Distribution of Glucosinolates in Different Phenotypes of Lepidium peruvianum and Their Role as Acetyl- and Butyrylcholinesterase Inhibitors—In Silico and In Vitro Studies. Int J Mol Sci. 2022 Apr 27;23(9):4858.
9. Rubio J, Caldas M, Dávila S, Gasco M, Gonzales GF. Effect of three different cultivars of Lepidium meyenii (Maca) on learning and depression in ovariectomized mice. BMC Complement Altern Med. 2006 Jun 23;6:23.
10. Ybanez-Julca RO, Quispe-Diaz IM, Asuncion-Alvarez D, Sanchez-Munoz K, Vargas-Gonas A, Morote-Guzman J, et al. Antidepressant-Like Behavioral and Spatial Memory Effects in Peruvian Red Maca (Lepidium meyenii)-Treated Rats. Pharmacognosy Journal. 2021 Jan 8;13(1):81–8.
11. Guo SS, Gao XF, Gu YR, Wan ZX, Lu AM, Qin ZH, et al. Preservation of Cognitive Function by Lepidium meyenii (Maca) Is Associated with Improvement of Mitochondrial Activity and Upregulation of Autophagy-Related Proteins in Middle-Aged Mouse Cortex. Evidence-based Complementary and Alternative Medicine. 2016;2016.
12. Fu P, Luo S, Liu Z, Furuhara K, Tsuji T, Higashida H, et al. Oral Supplementation with Maca Improves Social Recognition Deficits in the Valproic Acid Animal Model of Autism Spectrum Disorder. Brain Sci. 2023;13(2).