Maca (Lepidium meyenii)

Common Names:

• English: Maca, Peruvian Ginseng, Andean Ginseng
• Dutch: Maca, Peruaanse Ginseng, Andes Ginseng

Binomial Name:

Lepidium meyenii

Family:

Brassicaceae (Mustard family)

Used Plant Parts:

• Root (primary part used)
• Leaves (less commonly used)

Maca grows at 3,800–4,500 meters (12,500–14,800 feet) above sea level, making it one of the highest-altitude cultivated crops in the world.

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Origins, Distribution, and Habitat

Origin and Historical Background

Maca (Lepidium meyenii), often called Peruvian Ginseng, is a root vegetable native to the high-altitude regions of the Andes Mountains in Peru and Bolivia. It has been cultivated for over 2,000 years, primarily by the Inca civilization, which revered maca for its energy-boosting and fertility-enhancing properties.

Historical records suggest that Incan warriors consumed maca before battles to increase strength and endurance. However, after conquests, they were restricted from using it to preserve the fertility of captured women, highlighting its legendary status as an aphrodisiac. Spanish colonists later documented its use and even traded maca as a valuable commodity for gold and silver.

Geographical Distribution

Maca is endemic to Peru but has been introduced to other regions with similar climates. Today, it grows in:

• Central and Southern Peru – Primarily in the Junín and Pasco regions, where it thrives at extreme altitudes.
• Bolivia – Found in smaller quantities in the Andean highlands.
• China – Cultivated in select areas with controlled high-altitude conditions.
• Other Andean Countries – Small-scale cultivation exists in Ecuador and northern Argentina.

Although maca has gained global popularity, Peru remains the largest producer and exporter, with strict regulations to protect its cultural and agricultural heritage.

Preferred Habitat and Growing Conditions

Maca is one of the few crops capable of surviving in harsh, high-altitude environments, typically between 3,800 to 4,500 meters (12,500 to 14,800 feet) above sea level. It thrives in:

• Rocky, mineral-rich soils – The Andean highlands provide nutrient-dense volcanic soil, essential for maca’s growth.
• Extreme temperatures – Maca tolerates freezing nights (-10°C/14°F) and intense daytime sun (20°C/68°F).
• Low oxygen environments – Few plants can survive at such elevations, making maca a unique, highly adaptable crop.

Despite these challenging conditions, maca is resilient and often grown as a rotation crop to restore soil nutrients.

Ecological Role

Beyond its agricultural and medicinal value, Lepidium meyenii plays an important ecological role:

Supports local biodiversity – As a traditional crop, maca cultivation maintains ancestral farming practices and helps preserve Andean agricultural heritage.

Prevents soil erosion – Its deep-rooted system helps stabilize Andean soil.

Botanical Description:

Plant Structure and Growth Habit

Maca (Lepidium meyenii), a member of the Brassicaceae (mustard) family, is a biennial or annual herbaceous plant primarily cultivated for its underground root. Unlike most root crops, maca is uniquely adapted to high-altitude environments, thriving in the harsh Andean climate.

It has a low-growing, rosette-like structure, typically reaching a height of 10–20 cm (4–8 inches) above the soil. The plant’s resilience allows it to survive strong winds, extreme temperature fluctuations, and nutrient-poor soils.

Leaves and Foliage

The leaves of maca grow in a basal rosette, meaning they form in a circular pattern close to the ground. Key characteristics include:

• Shape – Initially oval and smooth, but later developing into deeply lobed, feathery leaves as the plant matures.
• Size – Young leaves are small, but older leaves can reach up to 10 cm (4 inches) in length.
• Color – Varies from light green to dark green, depending on growing conditions.

Maca’s leaves play a minor role in its commercial use but are occasionally harvested for animal fodder or local medicinal preparations.

Flowers and Reproductive Features

Maca produces small, self-fertile flowers typical of the mustard family. These flowers exhibit:

• Pale yellow to white petals, forming clusters at the top of the flowering stem.
• Four-petaled structure, a common trait of plants in the Brassicaceae family.
• Tiny size, usually no more than 3–5 mm (0.1–0.2 inches) in diameter.

Pollination occurs primarily through wind or self-fertilization, ensuring successful reproduction even in the isolated high-altitude regions where it grows.

Root System and Variability

The most important part of maca is its hypocotyl, the swollen underground structure often mistaken for a true root. This fleshy, turnip-like organ serves as the nutrient storage center of the plant. Notable features include:

• Shape – Round, oval, or elongated, resembling a radish or small turnip.
• Size – Typically 4–8 cm (1.5–3 inches) in diameter, though some can grow larger in ideal conditions.
• Color Variations – Maca comes in several color varieties, including:
  • Yellow (the most common, mild-flavored variety)
  • Red (considered the most nutrient-dense)
  • Black (associated with higher energy content and resilience to harsh conditions)
  • Purple, cream, and green varieties, though less common

These different colors are not just cosmetic—they also indicate variations in phytochemical composition, leading to diverse nutritional and medicinal properties.

Seed Production and Dispersal

After flowering, maca develops tiny, round seed pods, each containing one to two small seeds.

• Size – Approximately 2 mm (0.08 inches) in diameter.
• Color – Light brown or tan.
• Dispersal Method – The plant relies on wind dispersal or human cultivation to spread.

Due to its high-altitude environment, maca does not face significant competition from other plants, allowing its seeds to germinate successfully with minimal interference.

Adaptations to Extreme Conditions

Maca thrives in one of the world’s harshest agricultural environments, surviving at elevations of 3,800 to 4,500 meters (12,500 to 14,800 feet). Its adaptations include:

• Resistance to freezing temperatures, allowing it to survive nightly frosts.
• Efficient water absorption from the thin, rocky Andean soil.
• Strong underground storage to conserve energy and nutrients, ensuring survival in nutrient-poor conditions.

Maca contains over 60 different phytochemicals, including 20 amino acids, high levels of iron, calcium, and essential fatty acids.

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Active Compounds

Maca (Lepidium meyenii) is a nutritionally dense root that contains a unique blend of bioactive compounds, contributing to its resilience in extreme environments and its traditional value as a staple food in the Andes.

These compounds influence the plant’s flavor, aroma, and biochemical composition, making maca a subject of increasing scientific interest.

Macamides – Unique Maca Compounds

One of the most distinctive sets of compounds in maca are macamides, which are long-chain fatty acid derivatives unique to this plant. These compounds:

• Are believed to contribute to maca’s adaptability to extreme climates.
• Play a role in lipid metabolism (how fats are processed and stored in plant cells).
• Are structurally similar to cannabinoids (compounds that interact with the body’s endocannabinoid system), though their exact function in maca remains under study.

Macamides are not found in any other known plant species, making them a signature chemical marker for authentic maca.

Glucosinolates – Natural Plant Defense Compounds

Like many plants in the Brassicaceae (mustard) family, maca contains glucosinolates (sulfur-containing compounds responsible for the spicy or bitter taste of cruciferous vegetables). These compounds:

• Help the plant defend itself against insects and environmental stressors.
• Are precursors to isothiocyanates (compounds released when plant tissues are broken down).
• Contribute to maca’s earthy, slightly spicy flavor.

The glucosinolate content varies among different maca root colors, with black and red maca often containing higher concentrations than yellow maca.

Polyphenols – Antioxidant Compounds

Maca is rich in polyphenols (naturally occurring antioxidants that protect plant cells from damage). Key polyphenols in maca include:

• Flavonoids – Plant pigments that help absorb UV light and protect against oxidative stress (damage from free radicals, unstable molecules that can harm cells).
• Phenolic acids – Compounds that support plant growth and defense mechanisms.

These polyphenols contribute to maca’s ability to withstand intense sunlight in the high-altitude Andes.

Alkaloids – Nitrogen-Based Plant Compounds

Maca contains alkaloids, a group of naturally occurring nitrogen-based compounds that often influence growth and survival in plants. Though present in small amounts, the alkaloids in maca:

• Contribute to nutrient transport within the plant.
• May help regulate plant metabolism in extreme conditions.

Unlike some toxic alkaloids found in related plants, maca’s alkaloids are non-toxic and safe for consumption.

Sterols – Natural Plant Lipids

Maca contains sterols, which are plant-derived compounds similar in structure to cholesterol but with different biological functions. The most abundant sterols in maca include:

• Beta-sitosterol – A plant sterol that supports cell membrane stability.
• Campesterol – Involved in plant growth and hormone balance.
• Stigmasterol – Helps maintain structural integrity in plant cells.

These sterols assist the plant in adapting to low-oxygen, high-altitude conditions.

Essential Amino Acids – The Building Blocks of Proteins

Maca is a rare plant that contains all nine essential amino acids (the protein components that the body cannot produce on its own). These amino acids:

• Play a role in plant tissue repair and regeneration.
• Help the plant synthesize enzymes and structural proteins.

This high amino acid content makes maca a nutrient-dense crop, essential for survival in harsh Andean conditions.

Uses in Traditional Medicine

For over 2,000 years, Lepidium meyenii, commonly known as maca, has played a central role in Andean traditional medicine. Indigenous communities in Peru and Bolivia have long used this hardy root as both a staple food and a medicinal remedy.

Over time, maca’s reputation spread beyond the Andes, reaching Spanish explorers, European herbalists, and even Dutch apothecaries.

Andean Civilizations: The Sacred Root of the Incas

Maca was a vital crop for the Inca civilization, where it was considered a sacred plant. Its ability to thrive at extreme altitudes in the high Andes (3,800–4,500 meters above sea level) made it an essential food source for survival.

• Warrior’s Tonic – Inca warriors reportedly consumed maca before battles to enhance physical endurance and mental focus. After conquests, its use was restricted to prevent excess fertility and aggression.
• High-Altitude Adaptation – Andean healers gave maca to travelers and messengers crossing the mountains to help them adjust to low oxygen levels and extreme cold.
• Fertility and Reproductive Health – Indigenous Quechua and Aymara communities used maca to increase fertility in both humans and livestock. It was often fed to llamas and alpacas to improve breeding success.

In traditional Andean medicine, maca was prepared in various forms:

• Dried and ground into flour, used to make porridges and flatbreads.
• Boiled into a sweet, thick drink called “maca chicha”, consumed during religious ceremonies and festivals.
• Fermented into a medicinal tonic, given to women after childbirth to restore strength.

Spanish Conquistadors and the European Introduction

When Spanish explorers arrived in the Andes in the 16th century, they observed the unusual endurance and fertility of the indigenous people and their livestock. Conquistadors quickly adopted maca as a valuable trade commodity.

• Maca for Colonial Soldiers – Spanish soldiers consumed maca to help them cope with the harsh Andean climate and maintain stamina during long military campaigns.
• Trade with the Spanish Crown – The Spanish exported maca to Spain, where it was introduced as an herbal remedy for vitality among the European elite.

By the 17th and 18th centuries, maca was listed in Spanish botanical texts, but its popularity remained largely confined to Andean populations.

Maca in Dutch Herbal Medicine

Although not widely used in historical Dutch herbalism, maca did find limited use in European apothecaries during the colonial period. Dutch merchants, known for their extensive trade routes, encountered maca through Spanish networks.

• Recorded in Early Herbal Texts – Some Dutch botanical references mention maca as a tonic herb, although it was not cultivated in Europe.
• Rare Exotic Medicine – Maca was considered a curiosity rather than a mainstream remedy, occasionally sold in apothecaries catering to wealthy clientele.

Unlike ginseng and other adaptogenic herbs, maca never became widely integrated into traditional Dutch medicine, as it remained difficult to cultivate outside the Andes.

Traditional Use in Other Cultures

Maca’s reputation extended beyond South America and Europe, finding small-scale use in other traditional medicine systems:

• China – Early botanical explorers introduced maca to Chinese herbalists, who compared it to ginseng for its purported energy-boosting effects.
• Africa – Traders brought maca to North African markets, where it was sometimes used as an ingredient in herbal fertility blends.

Inca warriors consumed maca before battle, believing it boosted strength and stamina, a tradition that dates back over 2,000 years.

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Evidence-Based Medical Applications

1. Hormonal Regulation and Reproductive Health

Several studies confirm Lepidium meyenii‘s ability to regulate hormonal balance and improve fertility. A controlled study[1] showed that Maca consumption increased luteinizing hormone (LH) levels by 4.5-fold and follicle-stimulating hormone (FSH) levels by 19-fold in female rats (Uchiyama et al., 2014).

In men, Maca significantly improved[2] sperm concentration, motility, and seminal volume after 12 weeks of supplementation (Melnikovová et al., 2015).

Mechanism:

• Macamides modulate the hypothalamic-pituitary-gonadal (HPG) axis.
• Bioactive compounds enhance sperm production and oocyte maturation.

2. Sexual Function Enhancement

Maca improves sexual function and libido in both men and women. A placebo-controlled study demonstrated that Maca extract increased sexual desire by 40% after 6 weeks of use (Tafuri et al., 2019).

Mechanism:

• Alkaloids in Maca enhance dopamine and serotonin levels, improving mood and sexual desire.
• Increased nitric oxide production improves blood flow to genital tissues.

3. Energy and Fatigue Reduction

Clinical trials indicate that Maca supplementation reduces fatigue and improves endurance. A double-blind study[3] found that Maca extract enhanced physical performance in trained athletes after 14 days of use (Gao et al., 2019).

Mechanism:

• Maca polysaccharides increase mitochondrial efficiency and ATP production.
• Adaptogenic compounds regulate cortisol levels, reducing stress-related fatigue.

4. Cognitive and Neuroprotective Benefits

Maca has neuroprotective effects, reducing oxidative stress in brain tissues. A study[4] found that Maca extract reduced infarct volumes in rats subjected to cerebral ischemia-reperfusion injury (Pino-Figueroa et al., 2010).

Mechanism:

• Flavonoids act as antioxidants, reducing neuroinflammation.
• Improved synaptic plasticity enhances cognitive function.

5. Anti-Inflammatory and Pain Relief Properties

Maca inhibits soluble epoxide hydrolase (sEH), reducing inflammatory pain. A study found that N-benzyl-linoleamide, a Maca constituent, reduced LPS-induced inflammatory pain in rodents (Singh et al., 2020).

Mechanism:

• Alkaloids modulate prostaglandin synthesis, reducing inflammation.
• Enhanced endocannabinoid activity improves pain tolerance.

Applications Requiring Further Research

1. Cancer Prevention

Some Maca-derived compounds exhibit cytotoxic effects against cancer cell lines. A study found that (+)-Meyeniin A inhibited proliferation of HL-60, A549, and MCF-7 cancer cells with an IC50 of 14.41 μM (Zhou et al., 2017).

Proposed Mechanism:

• Imidazole alkaloids induce apoptosis in tumor cells.
• Macamides regulate oncogenic signaling pathways.

2. Cardiovascular Health

Preliminary research suggests Maca improves lipid metabolism and endothelial function. A 12-week study[5] observed a 10% reduction in LDL cholesterol in Maca-treated subjects (Ciocoiu et al., 2016).

Proposed Mechanism:

• Increased nitric oxide availability enhances vasodilation.
• Polyphenols modulate lipid metabolism and reduce oxidative stress.

3. Antiviral Activity Against HIV-1

Maca alkaloids have shown potential in inhibiting HIV-1 replication. A study[6] identified three thiadiazole alkaloids that inhibited viral integration and entry into host cells (Apaza-Ticona et al., 2024).

Proposed Mechanism:

• Maca inhibits NF-κB transcription factors involved in viral replication.
• Alkaloids block viral integration into host DNA.

4. Osteoporosis and Bone Health

Preliminary animal studies suggest Maca may enhance bone mineral density. Increased calcium and magnesium retention has been observed[7] in Maca-fed rodents (Gonzales et al., 2001).

Proposed Mechanism:

• Glucosinolates enhance osteoblast differentiation.
• Flavonoids inhibit osteoclast activity, reducing bone resorption.

Recommended Dosage

Standardized Dosage for Adults

General Health and Energy Enhancement

Studies suggest that Maca can improve stamina, mood, and energy levels. A randomized controlled trial[8] administered 1.5 g to 3 g daily for 12 weeks, reporting improved well-being without adverse effects (Gonzales et al., 2003).

Reproductive Health and Fertility

For male fertility improvement, 1.5 g to 3 g per day significantly increased sperm count and motility over a four-month period (Gonzales et al., 2001). A separate study showed enhanced sperm concentration after consuming 1.75 g per day for 12 weeks (Melnikovová et al., 2015).

Libido and Sexual Function

A double-blind clinical [9]. Andrologia, 41, 95-99. https://doi.org/10.1111/j.1439-0272.2008.00892.x” class=”js–wpm-format-cite”>trial[9] on men with mild erectile dysfunction found that 2.4 g per day for 12 weeks improved sexual well-being (Zenico et al., 2009).

Endurance and Physical Performance

A trial[10] in athletes found that 1.5 g per day for 60 days increased oxygen consumption by 10.3%, leading to better endurance (Ronceros et al., 2013).

Hormonal Balance in Women

For menopausal symptom relief, Maca extract at 3.5 g per day for 6 weeks showed[11] beneficial effects in reducing symptoms like hot flashes and mood swings (Meissner et al., 2006).

Cognitive Function and Neuroprotection

Animal studies[12] indicate that Maca enhances cognition. 1 g/kg body weight daily improved memory and learning in aging rats (Pino-Figueroa et al., 2010).

Standardized Dosage for Children

Nutritional Support

Maca is used in Peruvian high-altitude regions to enhance growth and energy. Traditional consumption in children ranges from 0.5 g to 1 g daily in powdered form mixed with food or beverages (Gonzales, 2012).

Cognitive and Developmental Benefits

There are limited clinical studies on children, but historical use suggests a safe range of 250 mg to 500 mg daily for improving energy and brain function (Gonzales, 2012). More research is required for definitive recommendations.

Side Effects

1. Hormonal Effects and Endocrine Disruptions

Maca is known to influence hormonal activity, particularly because it contains glucosinolates and macamides (compounds that may interact with hormone regulation). While maca itself does not contain phytoestrogens or hormones, some studies suggest that it may stimulate the endocrine system, affecting:

• Menstrual Cycle Irregularities – Some women report changes in their menstrual cycles, such as shorter or longer periods, after consuming maca for an extended time.
• Exacerbation of Hormone-Sensitive Conditions – Individuals with polycystic ovary syndrome (PCOS), endometriosis, or estrogen-sensitive cancers should use maca cautiously, as it may stimulate estrogen or testosterone activity.
• Acne and Skin Reactions – Due to its possible effect on androgen (male hormone) levels, some users experience increased oil production and acne breakouts.

2. Thyroid Function Concerns

Maca is part of the Brassicaceae (mustard) family, which includes plants known to contain goitrogens (compounds that may interfere with thyroid hormone production). In individuals with hypothyroidism (underactive thyroid) or iodine deficiency, maca may:

• Disrupt normal thyroid hormone synthesis, potentially leading to fatigue, weight gain, or metabolic slowdown.
• Increase the risk of goiter formation (thyroid gland enlargement) when consumed in large amounts over time.

3. Digestive Issues

Although maca is easily digestible when cooked or gelatinized, raw maca root may cause gastrointestinal discomfort in some individuals. Possible effects include:

• Bloating and gas due to its high fiber content.
• Mild stomach cramps when consumed in large amounts.
• Diarrhea or loose stools, particularly in individuals with sensitive digestive systems.

Traditionally, Andean populations boil or ferment maca to reduce digestive side effects.

4. Sleep Disruptions and Overstimulation

Maca is often described as energizing, similar to caffeine-free adaptogens like ginseng. However, excessive consumption may lead to:

• Insomnia or restless sleep, especially when taken in the evening.
• Increased heart rate or mild palpitations in sensitive individuals.

Those prone to anxiety, high stress levels, or nervous system overstimulation should consider starting with low doses of maca.

5. Blood Pressure Fluctuations

Some studies suggest that maca may have an impact on blood circulation and cardiovascular function. Potential risks include:

• Increased blood pressure (hypertension) – In some users, maca may elevate systolic and diastolic blood pressure, especially at high doses.
• Lowered blood pressure (hypotension) – In contrast, other reports indicate that maca’s effect on blood vessel dilation may lead to dizziness and lightheadedness in those with already low blood pressure.

Drug Interactions

1. Hormone-Based Medications

Due to its potential endocrine-modulating effects, maca may interfere with:

• Birth control pills – It may reduce effectiveness in some individuals by influencing hormone metabolism.
• Hormone replacement therapy (HRT) – Maca may alter estrogen and testosterone levels, possibly counteracting or enhancing the effects of synthetic hormones.
• Thyroid medications (Levothyroxine, etc.) – As a goitrogenic plant, maca may reduce the absorption of thyroid medications in individuals with hypothyroidism.

2. Medications for High or Low Blood Pressure

Maca’s effects on circulation may interact with drugs that regulate blood pressure, including:

• Antihypertensive medications (for high blood pressure) – Maca may either enhance or weaken the effects, leading to unstable blood pressure levels.
• Vasodilators (for heart conditions) – Because maca can increase nitric oxide levels, it may potentiate the effects of vasodilators, leading to excessive blood flow changes.

3. Diabetes Medications

Some studies indicate that maca may help regulate blood sugar levels, which could interfere with:

• Insulin therapy – Maca may increase insulin sensitivity, leading to unexpected drops in blood sugar (hypoglycemia).
• Oral antidiabetic drugs (Metformin, etc.) – Its effects on glucose metabolism may enhance or counteract the medication’s impact.

4. Anticoagulants and Blood Thinners

Maca contains flavonoids and sterols that may influence blood clotting. This could be problematic for individuals taking:

• Aspirin, Warfarin, or other blood thinners – Maca may increase the risk of bleeding or alter clotting times.

There are at least three primary maca root colors (yellow, red, and black), each with different bioactive compound compositions and traditional uses in Andean medicine.

Fact 4 of 4

Bibliography