Maca (Lepidium meyenii) and yacon (Smallanthus sonchifolius) in combination with silymarin as food supplements: in vivo safety assessment.

2008-03
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 46(3)
- Katerina Valentová
- David Stejskal
- Josef Bartek
- Svatava Dvorácková
- Vladimír Kren
- Jitka Ulrichová
- Vilím Simánek

PubMed: 18054420
DOI: 10.1016/j.fct.2007.10.031

Study Design

Type: Randomized Controlled Trial (RCT)
Population: patients suffering from the metabolic syndrome
Methods: randomized placebo-controlled study
Blinding: Double-blind
Duration: 90-day
Funding: Unclear

Yacon and maca are native Andean crops with growing popularity as food supplements often in combination with other components, e.g. silymarin. There are however no published data on their toxicity and safety in humans. The aim of our randomized placebo-controlled 90-day study was to evaluate the effects of yacon and maca in combination with silymarin on plasma and lipoprotein lipids, serum glucose and safety parameters in patients suffering from the metabolic syndrome. No adverse effects were found in volunteers using silymarin (0.8 g/day), silymarin+yacon (0.8+2.4 g/day) and silymarin+maca (0.6+0.2 g/day). A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day). In conclusion, the combination silymarin+yacon appears to be promising as a nutraceutical in the prevention of diseases with a proatherogenic lipoprotein profile and liver steatosis. The effect of maca on AST level and blood pressure must be considered when using high doses of maca powder. This effect could be reversed by supplementation with silymarin.

Research Insights

Thistle→Reduced Aspartate Aminotransferase Level
No adverse effects were found in volunteers using silymarin (0.8 g/day), silymarin+yacon (0.8+2.4 g/day) and silymarin+maca (0.6+0.2 g/day). A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day).
Effect
Neutral
Effect size
Small
Dose
0.8 g/day
Thistle→Reduced Diastolic Blood Pressure
A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day).
Effect
Harmful
Effect size
Moderate
Dose
0.6 g/day
maca→Increased IL-12 Levels
A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day).
Effect
Harmful
Effect size
Moderate
Dose
0.6 g/day
maca→Reduced Diastolic Blood Pressure
A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day).
Effect
Harmful
Effect size
Moderate
Dose
0.6 g/day

Adverse Events Reported

maca→ast level increase
A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day).
Finding
Increased risk
Grade
moderate
maca→diastolic blood pressure increase
A moderate AST level and diastolic blood pressure increase was found in volunteers using maca (0.6 g/day).
Finding
Increased risk
Grade
moderate
Thistle→Overall tolerability
No adverse effects were found in volunteers using silymarin (0.8 g/day), silymarin+yacon (0.8+2.4 g/day) and silymarin+maca (0.6+0.2 g/day).
Finding
Reported