Unspecified Color

Summary of Findings:

• Unspecified color of maca was taken at a dose of 200 mg twice daily by women reporting fatigue

• Significant decrease in fatigue (p<0.001), as measured by visual analogue scale (VAS) in women 20-45 yo

Summary of Findings:

• Unspecified color of maca was taken in a dose of 1,000 mg twice daily

• Significant increase in sperm concentration (p<0.011) by 31.69%

• Though not of statistical significance, sperm motility increased by 10.48% and morphology of spermatozoa increased by 6.33%.

Summary of Findings:

• Unspecified color of maca known as Maca-BG1.2, was taken in a dose of 300 mg per day

• E2 level showed a 2.2-fold increase though not of significance; further analysis revealed serum E2 level in the peri-menopausal subjects with regular menstruation cycle displayed a mostly significant change

• Marginal decrease in insomnia and hot flushes. 

• Women with mild symptoms achieved the greatest improvements in reducing menopausal symptoms. 

Summary of Findings:

Maca extract 

• Significantly suppressed multiple inflammatory cytokines

• Moderated liver injury in ConA-induced acute hepatitis

• Suppressed infiltration of natural killer T cells and macrophages

• "In this study, we found that the protective effects of Maca extract ameliorate ConA-induced acute hepatitis (CIH) and underlying mechanisms."

Summary of Findings:

• Maca treated mice had improvements in memory retention.

• Improved motor coordination was observed in mice that were administered maca. 

• A significant increase in swim time to exhaustion, suggesting maca's antifatigue property.

• A significant increase in oxidative phosphorylation enzyme complexes, suggesting an improvement in mitochondrial function. 

• A significant upregulation of the expression of autophagy-related proteins.

• "In summary, the present study demonstrated for the first time that maca improves cognitive function in middle-aged mice, and this effect may be associated with improved mitochondrial respiratory function and upregulation of autophagy-related proteins."

Summary of Findings:

Unspecified color of maca was taken for 6 weeks at a dose of 3.3 grams per day, with a 6-week crossover of placebo.

After 6 weeks of treatment, the maca group showed significant changes in:

• Decrease in systolic (p=0.05) and diastolic (p=0.01) blood pressure

• 10.8% increase general well-being (p<0.05)

• 13.5% increase mental health (p<0.05)

• 16.4% increase social functioning (p<0.05)

• 13% increase mental component score (p<0.05)

• Significant reduction of menopausal symptoms measured by GCS by 30% (p=0.04) including reduction in anxiety (p=0.02, depression (p<0.01) and somatic (p<0.03);

• No differences in E2, FSH, LH, SHBG, glucose, lipid profile, serum cytokines or vasomotor symptoms

Summary of Findings:

• An ethanolic extract of maca was given to ovariectomized rats for 28 weeks in two doses, 0.096g/kg body weight (low dose) and 0.24 g/kg body weight (high dose).

• At 28 weeks, a significant increase in estradiol and a significant decrease in FSH was observed using the lose dose of maca. 

• The higher dose of maca did not affect estradiol levels. 

Summary of Findings:

• Female rats were fed 5%, 25% or 50% diet of maca.

• A significant increase in luteinizing hormone and follicle stimulating hormone levels (p<0.01). 

• "The present study demonstrates that Maca uniquely enhances the LH serum levels of pituitary hormones in female rats during the pro-oestrus LH surge and acts in a pharmacological, dose-dependent manner. These findings support the traditional use of Maca to enhance fertility and suggest a potential molecular mechanism responsible for its effects."

Summary of Findings:

Population based study, comparing individuals who consumed maca, as a food source, to those who did not.

Compared to non-consumer, the regular consumers of maca had: 

• Higher serum Estradiol (E2) (p<0.01) and health scores (p<0.01)

• Lower systolic blood pressure (p<0.05), serum T levels (p<0.05),T/E2 ratio (p<0.05), serum IL-6 levels (p<0.05), and CMS scores  (p<0.01)

• Performed better on the lower limb strength test (p<0.01)

• The lowest IL-6 levels were observed when maca was consumed in greater quantities (15.9+/- 3.08 grams per day) and for the longer durations (17.8 +/-4.48 years for 41.9+/- 4.48 days per year)

Summary of Findings:

• An unspecified color of maca was taken in a dose of 1 gram twice daily for 90 days. 

• Maca improved sperm motility (p<0.05)

Summary of Findings:

• Unspecified maca extract was consumed, 1 tsp. powder daily

• Maca consumption increased plasma testosterone levels without features of virilization. 

• Maca may cause testosterone immunoassay interference in females. (Testosterone immunoassays use direct immunoassays which are prone to interference from androgenic compounds resulting in falsely elevated testosterone levels.)

Summary of Findings:

• An unspecified color of maca was taken for 12 weeks by infertile men at a dose of 3,000 mg per day.

• The group taking maca experienced:

• Improvements in sperm motility (p<0.0001), vitality (p<0.01) and morphology (p<0.01), immature germ cell (p<0.01)

• No changes in hormone levels were observed.

Note: Article is in Spanish, details retrieved from English abstract. 

Summary of Findings:

• An unspecified maca extract was taken at a dose of 2,000 mg per day. 

• Maca extract significantly improved 40 km cycling time performance compared to the baseline test (P=0.01), but not compared to the placebo trial after supplementation (P>0.05). 

• Maca extract significantly improved the self-rated sexual desire score compared to the baseline test (P=0.01) and compared to the placebo trial after supplementation (P=0.03).

Summary of Findings:

• Unspecified color of maca was taken for 12 weeks in a dose of 1,200 mg twice daily

• Both the placebo group and maca group reported significant improvements,

• The maca group experienced more significant effects after 12 weeks of treatment including:

• International Index of Erectile Function (IIEF-5) score (p < 0.001)

• Improvement in psychological performance-related Satisfaction Profile (SAT-P) score, (p< 0.05).

• Only maca-treated patients experienced a significant improvement in physical and social performance-related SAT-P score compared with the baseline (p< 0.05).

Summary of Findings:

• Unspecified color of maca was taken for 12 weeks in a dose of 3.5 grams of maca powder one time per day

• No estrogenic or androgenic activity was detected in the maca used for the study.

• Significant reduction (p<0.05, 30%) in symptoms as rated by Greene Climatic Scale, including decreased anxiety and depression and improved sexual function (p<0.05)

• No differences were seen in serum concentrations of estradiol, follicle-stimulating hormone, luteinizing hormone, and sex hormone-binding globulin. 

• Post hoc analyses revealed significant increase in estradiol would only be detected at a 30% increase.

Summary of Findings:

• Unspecified color of maca was taken at either 1.5 g/day (low dose) or 3.0 g/day (high dose)

• Both groups had significant improvement in mean ASEX and MGH-SFQ score. 

• For the group taking 3 g/ day

• An increased improvement in sexual function was observed compared to the low dose groups, as measured by ASEX (p=0.028) and MGH-SFQ (p=0.017)

• Significant improvement in libido (P<0.05), with increased sexual attempts (p=0.048) and enjoyment (p=0.019)

• Small but significant decrease in depressive symptoms (p=0.047)

ASEX= Arizona Sexual Experience Scale; MGH-SFQ = Massachusetts General Hospital Sexual Function Questionnaire

Summary of Findings:

• Maca protected spermatogenesis and increased epididymal sperm count. 

• Maca administration reduced the deleterious effect on daily sperm production caused by lead acetate (LA) treatment. 

• Maca prevented LA-induced spermatogenic disruption in rats and it may become in a potential treatment of male infertility associated with lead exposure.

Summary of Findings:

• An extract of an unspecified color of maca was given for 28 weeks in two doses (0.096 or 0.24 g/kg body weight) to ovariectomized rats.

• "The findings derived from the basis of bone mineral density, biomechanical, biochemical and histopathological parameters indicated that higher dose of ethanol extract of Maca was effective in the prevention of estrogen deficient bone loss."

Summary of Findings:

• An unspecified maca extract was taken at a dose of either 1,500 mg or 3,000 mg per day

• At week 8, the group treated with maca had a significant increase (40%) in sexual desire (p<0.008);

• At week 12, the group treated with maca had a significant increase (42.2%) in sexual desire (p<0.006);

• No differences in the effect were noted between the dosing groups.

• No changes in hormone levels (testosterone or estradiol) or mood (depression/anxiety) were observed.

Summary of Findings:

A dose of 1,500 or 3,000 mg of maca was taken daily by men.

Maca increased: 

• Seminal volume

• Sperm count per ejaculation

• Motile sperm count

• Sperm motility

Dose did not impact the outcomes. 

Summary of Findings:

• Two formulas of unspecified colors of maca, called M-01 and M-02 were used. 

• M-01 contained more polysaccharides and less macaenes and macamides compared to M-02.

• "Oral administration of M-01 and M-02 enhanced the sexual function of the mice and rats, as evidenced by an increase in the number of complete intromissions and the number of sperm-positive females in normal mice, and a decrease in the LPE in male rats with erectile dysfunction."

• "The present study reveals for the first time an aphrodisiac activity of L. meyenii, an Andean Mountain herb."