Black Maca

Summary of Findings:

• A daily dose of 2,500 mg of black maca was taken twice daily in capsule form for 4 weeks

• Significant improvement in muscle endurance (p<0.05 and p<0.01)

• Significant improvement in cardiopulmonary endurance (p<0.001)

Summary of Findings:

• A daily dose of 5 grams per day of black maca was taken by men for 12 weeks. 

• Black maca resulted in significant improvements in Aging Males' Symptoms scale (AMS), International Index of Erectile Function (IIEF), and International Prostate Symptom Score (IPSS)  (p<0.0001)

• Further, Androgen Deficiency in the Aging Males (ADAM) score was significantly reduced (p<0.0001), showing an improvement in androgen deficiency symptoms. 

Summary of Findings:

Black maca extract (2,300 mg twice daily) was studied and resulted in:

• Significant increase in muscle endurance, agility, muscle strength, flexibility, and power 

• Significant decrease in inflammatory markers (IL-6 and TNF-a) 

• Significant increase in total cholesterol

• Significant decrease in lactic acid and C-reactive protein (statistical ranges vary based on the sport of the athlete)

Summary of Findings:

• Pregnant mice were injected with valproic acid during pregnancy. The male offspring, 6-12 weeks old, were examined in this study.

• Maca improved cognitive function and spatial memory in the mice models 

• Maca improved the mice's social acquisition and recognition. 

• Maca increased neuronal activation.

• "These results reveal for the first time that maca is beneficial to social memory and that it restores social recognition impairments by augmenting the oxytocinergic neuronal pathways, which play an essential role in diverse social behaviors."

Summary of Findings:

• 2.5 grams of black maca was consumed daily for 4 weeks.

• Black maca consumption resulted in a significant decrease in ammonia levels (p<0.05).

• Improvements in muscle endurance and strength (p<0.05) was noted with black maca intake.

Summary of Findings:

• Black maca (5 grams per day) was combined with regular exercise and resulted in a significant decrease in BMI, inflammatory markers (CRP and CK), and increased muscle endurance in 4 weeks.

Of note, only the abstract is available for this Korean language published article.

Summary of Findings:

• Aqueous extract of black maca (AEM) was studied. 

• 32 bioactive compounds targeting 16 proteins involved in metabolism disorders were identified.

• AEM promoted glycolysis, inhibited gluconeogenesis and upregulated tricarboxylic acid cycle. 

• Lipid lowering effects were also observed including enhanced fatty acid oxidation and lipogenesis pathway inhibition.

Summary of Findings:

• Black, yellow, and purple maca was investigated for their activity in diabetic rats.

• Black maca exhibited the highest levels of macamides.

• All maca extracts enhance antioxidant activity (superoxide dismutase and catalase) of the liver and red blood cells. 

• Glutathione levels were not enhanced with black maca. 

Summary of Findings:

• Men with mild erectile dysfunction took 5 grams per day of  either 1) gelatinized and dried  black maca OR  2) fermented black maca

• Sperm concentration and motility were significantly improved (p<0.05) in the groups taking black maca compared to placebo.

Findings of this study were reported in:  Lee MS, Lee HW, You S, Ha KT. The use of maca (Lepidium meyenii) to improve semen quality: A systematic review. Maturitas. 2016;92:64-69. doi:10.1016/j.maturitas.2016.07.013

Summary of Findings:

• Yellow and black maca were studied.

• Yellow maca had better antioxidant capacity compared to black maca. 

• Total phenolic content was better in the methanolic fraction than in the aqueous fraction of both yellow and black maca, though it was higher in black maca compared to yellow. 

• Methanolic extract of black maca resulted in higher concentration of sperm count in epididymis and vas deferens compared to yellow.

Summary of Findings:

• Participants living in low altitudes (LA) 150 meters above sea level in Lima, Peru and high altitudes (HA) 4,340 meters above sea levels in Cerro de Pasco, Peru were included in the study comparing efficacy of black and red maca.

• About 50% of all participants reported an increase in sexual desire.

• Higher quality of life was reported in both red and black maca groups (p<0.05).

• In HA participants, black maca reduced hemoglobin levels, glucose levels  (p<0.05),  systolic blood pressure (p<0.01) and chronic mountain sickness (p<0.05).

Summary of Findings:

• The effect of gamma irradiation of black and red maca were compared.

• Gamma irradiation increased antioxidant capacity. 

• Black maca contained higher polyphenols. 

• Higher swimming endurance capacity was observed in the black maca group, with irradiation increasing swimming time to exhaustion, which was not observed in red maca group.

• "In conclusion, irradiation does not alter the biological activities of both black maca and red maca extracts. It prevents the presence of microorganisms in the extracts of black or red maca, but the biological activities were maintained."

Summary of Findings: 

• Ethanol consumption can cause memory impairment. 

• Four doses of black maca (0.125, 0.25, 0.50 and 1.0 g/kg od body weight) were compared against ascorbic acid and a control for 28 days. 

• Mice treated with ascorbic acid and black maca reversed the deleterious effects of ethanol.

• The effects of deceased memory impairment caused by ethanol, was improved by black maca in a dose-dependent manner, likely due to its polyphenolic compounds. 

Summary of Findings:

• Red, yellow, and black maca demonstrated UVA/UVB absorptive properties and antioxidant activity.

• Highest activity was from red maca, followed by black and then yellow.

• Each of the three colors prevented the development of sunburns, epidermal hyperplasia, and leukocytic infiltration. 

• Black maca showed the highest superoxide dismutase levels and higher catalase levels in the skin.

Summary of Findings:

• Black maca decreased malonaldehyde (MDA) and acetylcholinesterase levels.

• Black maca increase latency and reduced the number of errors. 

• Black maca improved memory impairment induced by ovariectomy, due to is antioxidant and acetylcholinesterase inhibitory effects. 

Summary of Findings:

• Black and red maca reduced the negative effects of ovariectomy on bone health by increasing trabecular bone in the lumbar vertebrae.

• "Red and black maca have protective effects on bone architecture in OVX rats without showing estrogenic effects on uterine weight."

Summary of Findings:

• Increased daily sperm production with the ethyl acetate fraction of black maca.

• Increased sperm count in vas deferens with hydroalcoholic extract of black maca compared to other forms and control. 

• "Antioxidant components could play a role in the effect of increased epididymal sperm concentration observed in the model."

Summary of Findings:

• Two doses of aqueous extracts of black maca (0.50 and 2.0 g/kg of body weight) and two doses of hydroalcoholic extracts of black maca (0.25 and 1.0 g/kg body weight) were studied for its effect on memory impairment induced by scopolamine. 

• Both extracts of black maca significantly ameliorated the scopolamine-induced memory impairment.

• Black maca extracts inhibited acetylcholinesterase activity that was increased following scopolamine administration.

• Polyphenolic compounds, such as quercetin, anthocyanins, and alkaloids may be responsible for the favorable outcomes.

Summary of Findings:

• Black and yellow maca improved epididymal sperm count

• Black, yellow, and red maca improved sperm count in vas deferens.

• "Maca seems to act as a modulator of sperm count at the reproductive tract level."

Summary of Findings:

• Increased epididymal sperm count on days 1, 3, and 7 after the administration of black maca

• Increased vas deferens sperm count on days 3, 5, and 7 after the administration of black maca.

• Increased daily sperm production after 7days of treatment with black maca.

• "In conclusion, Black maca affects sperm count as early as 1 day after beginning of treatment."

Summary of Findings:

• Yellow, black, and red maca were studied

• Black maca provided the most beneficial effects on latent learning, particularly on trained mice though all phenotypes were effective for trained and non-trained mice (p<0.05)

• All varieties demonstrated anti-depressant effects.

Summary of Findings:

• Increased daily sperm production

• Increased epididymal sperm motility