Maca (Lepidium meyenii)

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What is Maca?

Maca is the highest altitude crop in the world.

It’s native to the high Andean mountains— known for being some of the most difficult climates in the world for a plant.

It’s fitting that a plant that can survive such stressful environments is used to improve our ability to endure stress.

Maca is a prime example of an adaptogenic plant.

Long term use has been shown to provide modulation of the hypothalamus pituitary adrenal axis (HPA axis), which is critically involved with the bodies stress response system.

Maca is also a popular herb for promoting libido and sexual fertility and overall function, as well as hormonal imbalances in men and women. Taking maca to achieve these effects needs to be regular, and in fairly high doses.

 

Featured Maca Supplements

 

What is Maca Used For?

Maca is mainly used as an aphrodisiac, athletic enhancement supplement, and to improve the bodies ability to resist stress. It is useful for adapting to altitude sickness, pushing through intense training regimens, and other high-stress periods.

Medicinally, it is useful for post menopausal women to prevent or resist osteoporosis, and to improve fertility in both men and women.

 

Traditional Uses of Maca

+ South America

Maca has been domesticated for about the last 2000 years by the Incas, and archaeologists have found primitive cultivars of the plant dating back as far as 1600 B.C [8].

The Andean Indigenous people's live in a region virtually inhospitable to most plants, with hot direct sunlight, high winds, and freezing temperatures all in the same place, not to mention the rocky, nutrient deficient soil. Maca is one of the few edible plants growing in that region, so it has significant value on the cultures living there. Maca is often traded with cultures living at lower elevations for other staple foods like rice, corn, green vegetables, and beans [8].

Peruvians in particular have used Maca for thousands of years both as nutrition and medicine (Taylor L. 2005). The root is eaten here either fresh, or dried, and is often cooked in a similar fashion as sweet potatoes. The dried roots are instead boiled in water or milk to make a porridge, or juice. Alcoholic drinks can be made and are referred to as Maca chica. Jams, puddings, and sodas can be made as well [5].

Maca has been used for centuries by various cultures in the Andes, including spanish conquistadors, as a fertility enhancing agent, in both humans and animals [5].

Today, Maca is still used in Peruvian medical systems to treat anemia, tuberculosis, menstrual disorders, menopause symptoms, stomach cancer, memory loss, reproductive disorders, and as an immunostimulant [8]. Throughout America, The United States, Europe, and Australia, Maca has been growing in popularity for a wide range of illnesses, and as a general health promoting agent through various attributes. Some of these include: fertility enhancement, aphrodisiac effects, sports performance, hormone balancing, increased stamina, male impotence, promoting mental clarity, menstrual irregularities, blood glucose balancing, and chronic fatigue syndrome.

+ Culinary Uses

The taste of Maca can be compared to that of butterscotch, with different varieties producing slightly different tastes and colours, but most producing a slightly tangy, sweet flavour.

 

Herb Details: Maca

Herbal Actions:

  • Adaptogenic
  • Anti-diabetic
  • Antioxidant
  • Aphrodisiac
  • Neuroprotective
  • Thyroid supportive

Weekly Dose

Part Used

Roots

Family Name

Brassicaceae

Distribution

South America, Andes mountains.

Constituents of Interest

  • Beta-ecdysone
  • Alkaloid content

Common Names

  • Maca
  • Peruvian ginseng
  • Peppergrass
  • Chichira

CYP450

Unknown

Nature/Taste

Unknown

Pregnancy

Unknown

Duration of Use

  • Avoid long-term use in therapeutic doses.

Botanical Information

Maca is part of the Brassicaceae or "mustard" family of plants. The Lepidium genera is one of the largest in the family.

Maca is famous for its incredibly high distribution. It thrives where very few other plants will grow, at altitudes of up to 4500 M above sea level.

+ Learn More

The hypocotyls (roots) are used nutritionally and medicinally, and resemble turnips in size and shape (in the same family). The root is cultivated in many South American countries, around the Andes mountains, particularly in the Carhuamayo, Junin, and Ondores in the Junin Plateau. The elevation of the mountains is necessary for the quality cultivation of this tuberous root vegetable. Typically, cultivators grow Maca as if it were an annual, even though technically it is a perennial. It takes roughly 7-9 months to produce roots ready for harvest.

Cultivation of this herb has grown substantially in recent years. Less than 50 hectares of land were devoted to the cultivation of this plant back in 1994, just 5 years later it was reported that 1200 hectares of land were in use for Maca production [8]. In fact, the exportation of maca from Peru has increased from 1,415,000 USD in 2001 to USD 6,170,000 USD in 2010 [2].

+ Confusion Around The Species

Although Maca is often listed as Lepidium meyenii most Maca is a different species (L. Peruvianum). This was backed up when a study done investigating the similarities of the two species, found that the Maca cultivated in the Peruvian Andes was indeed L. peruvianum [4].

This same study also confirmed that although many sources will refer to L. Meyenii, and L. peruvianum as synonymous, they are in fact dissimilar. This brings questions as to which species of “Maca” has actually been used in many of the scientific literature simply referring to its common name as “cultivated Peruvian Maca”.

+ Red, Black, and Yellow Maca

13 varieties of maca have been described ranging in color (and thus common name) from white, red, yellow, and black, with yellow being the most frequent [5]. Of the varieties, slight differences in biological properties have been reported.

Black maca has presented the greatest effect on spermatogenesis, and latent learning, though did not have as strong an effect on prostate reduction as compared to other varieties [5]. Black maca has also been reported to have positive effects on sperm motility [2].

Red maca was shown to have the strongest effect on prostate size [5], but little effect on sperm motility [2].

Yellow maca was noted to have a positive effect on sperm counts in rats, as well as improved sperm motility, and a medium effect on prostatic-hyperplasia [2]. All three varieties (yellow, black and red) were noted to have the same effect on depression in mice [5].

 

Habitat, Ecology, Description

Maca is found in the central Peruvian Andes [2], usually about 3500 meters or more above sea level. There seems to be much debate over what altitude is preferred by this plant, some sources listing an exclusive altitude between 4000 meters, and 4500 meters above sea level [2], others listing that it grows between 8000 and 12000 feet (~2500 - 3600 meters) [8].

Whatever the case, it is apparent that maca needs the high altitude in order to thrive. With this comes, searing hot sun at times, freezing cold weather at others, high winds, and often periods of intense dryness.

 

Harvesting, Collection, & Preparation

Maca (of all varieties), is generally found in dried, powdered form, due to its ease of use, and long shelf life. The hypocotyls of Peruvian Andes maca, range in size greatly, and fall into a range from about 7g to 24g of dried hypocotyls each [2]. Fresh roots contain about 80% water, and look about the size of turnip.

Gustavo F. Gonzales (2012) makes note that the boiling or otherwise heating of maca roots changes the metabolite levels. He reports that the aqueous extract of maca effective if it has been boiled, and suggests that the boiled aqueous extract, has similar effect as hydroalcoholic extract of Lepidium spp.

Maca contains glucosinolates, which are sensitive to heat. On the other hand, sulforaphane in maca is actually increased if undergone heating. Other metabolites influenced by heat include antioxidants (found to increase with heat in tomatoes), and Vitamin C (heat sensitive) [2].

Other factors to note when preparing maca for medicinal purposes, is to consider the variety. Red maca is best for prostate hyperplasia with yellow a good second choice, and black for increasing fertility, with yellow following behind as a good second choice for this a well. All three work close to the same on depression. Since yellow maca is by far the most common on the market today, it can be suggested that yellow maca is a good choice for most medicinal uses of maca.

 

Pharmacology & Medical Research

+ Adaptogen

The term "adaptogen" refers to plants or other substances that augment non-specific resistance in the body, and help the body to adapt to various situations. Therefore protecting it from stressful events and factors. [9].

Therefore, it could be argued that maca may fall under the classification of an adaptogenic botanical based on the following effects: supportive effect of the HP axis [4], antioxidant, fertility enhancing effects, and Neuroprotective effects [2].

The effects maca appears to produce on the HP axis, in turn, improves the function of endocrine glands throughout the body, provide a non-specific effect on vitality, and adaptability in the body through various organ systems. These effects can be noted in macas antidiabetic, neuroprotective, antidepressant, anti-stress, fertility enhancing, aphrodisiac, antihypertensive, and menopausal supportive effects. All of these pathologies are corrected by improving the normal functioning of the body, rather than through stimulation of processes in a single direction. The author notes that he has not found evidence of bidirectional action in maca. However, he has noticed the effects are normalizing in almost all aspects of the effects produced. A few exceptions include maca inhibitory effects on angiotensin I-converting enzyme [2], more research is needed in this area to determine how far this inhibition will go.

The very low toxicity noted in maca is another important factor to consider in classifying this substance as an adaptogen.

At this time, the author suggests Lepidium meyenni, and L. peruvianum should be considered and researched further as an adaptogenic botanical.

+ Depression

A study done comparing the effectiveness in three varieties of maca (yellow, red, black), found that all three had a similar effect on depression in mice [5].

+ Hypertension

Maca was shown to significantly inhibit angiotensin I-converting enzyme (ace) in vitro [2]. This enzyme, as well as potassium, which is contained in fairly high amounts, are both relevant in the pathophysiology of hypertension. Thus maca may produce antihypertensive effects.

+ Osteoporosis

Extracts of both red maca, and black maca have both shown protective effects in the bones of ovariectomized rats, while appearing not to affect estrogen levels [2], providing some evidence that maca has anti-osteoporosis effects in postmenopausal mammals.

+ Antioxidant

Black maca has been reported to provide support in memory impairment, through its antioxidant, and Ache inhibitory effects [2].

+ Prostatic Hyperplasia

It has been reported by various studies that red maca has the most significant effect on prostatic-hyperplasia [2, 5], with yellow maca offering intermediate support for the condition.

The constituents to be held responsible for these effects are under debate; however, with some researchers suggesting benzyl glucosinolates, and others suggesting polyphenols [2].

With treatment of red maca on TE-treated rats, effects were reversed, reducing prostate weight and zinc levels, however, no change was observed on seminal vesicle weight which is another organ dependent on androgen [2]. These results offer more indication that macas effects on the sexual organs are not through androgen receptors.

+ Aphrodisiac

N. S. Chauhan et al., (2014) reports that the improved sexual desire in both males and females is not related to changes in the pituitary or gonadal hormones. They note that maca does not activate androgen receptors, and conversely may, in fact, block androgen receptors instead.

This evidence was contradicted by other research investigating macas effects on hormones in relation to menopausal symptoms, these researchers suggested the effects produced were a result of HP axis related activity from the alkaloids contained within maca, which in turn improve the function of the adrenals and thus, androgen production [4].

The conflicting evidence may be a result of the design of the studies.

+ Athletic Performance

Despite various companies, and websites advertising as such, maca does not affect serum testosterone, or intratesticular testosterone [2], or other pituitary, and gonadal hormones. It doesn't appear to function through stimulation of the androgen receptors [6], though this evidence is conflicting, and suggested to affect these receptors as a secondary process from the improvement of the HP axis instead [4], possibly through normalizing effects rather than stimulation.

+ Fertility

The fertility-enhancing effects of maca were reported back in 1961, and since then has been the subject of much research looking closer at these effects. [2, 8].

Taylor L. (2005), warns that many of the research conducted on maca has been funded by two foremost marketers of Maca products in the United States. She also warns of studies conducted that measure libido enhancement, as this is a very subjective measurement, and should not be taken as hard scientific evidence.

Taylor L. (2005) suggests that the fertility, and libido enhancing properties of maca, may simply be a result of Macas high protein, and vital nutrient profile. Dried Maca root contains roughly 10% protein, derived from amino acids, these amino acids are necessary for many cellular functions within the body, including sexual processes (Taylor L. 2005). She refers to the neurotransmitters dopamine, and noradrenaline which both play a major role in sexual arousal, and physical performance during sex. These neurotransmitters require phenylalanine, tyrosine, and histidine, all of which are contained within Maca root.

Arginine is another amino acid with strong connections to fertility, especially in males. There are multiple libido enhancement supplements on the market that contain arginine for this reason (Taylor L. 2005). N. S. Chauhan et al. (2014) reports the improvement of L-arginine-nitric oxide activity from Maca use and relates this to a decrease in ejaculation latency in mice.

Histidine is another amino acid contained in Maca root that plays an important role in sexual function specifically for men. The body uses histidine to produce histamine, which is then used in the corpus cavernosum to produce ejaculation [8]. Maca, therefore, may be useful in treating fertility problems relating to anorgasmia, due to its histidine content.

A study done investigating the effects of various plant medicines on sexual performance and virility, suggests the mechanism of action of L. meyenii on virility, lies in its action on spermatogenesis and decreases in the latent period of erection and ejaculation. This effect was noted to be much more significant in mice with less sexual experience, or mice with ED, and disappeared over prolonged use [6]. This suggests a normalizing, over stimulating effect, which is parallel to the thoughts suggested by Taylor L. (2005) placing responsibility on maca's nutritional profile for its impact on sexual performance and virility.

Gustavo F. Gonzales (2012) reports that maca has been found to increase sperm count in both normal rats, as well as rats with pathological conditions produced from exposure to high altitude, lead acetate, and malathion. He also notes yellow maca, and black maca, had a positive effect on sperm motility, but no effects were noted in this area from red maca.

Both histidine and arginine also offer vasodilation effects within the body [8], which in turn increase blood flow to the sex organs in both males and females.

According to Gustavo F. Gonzales (2012), macaenes and macamides have been reported to have probable responsibility as well with the improved sexual behavior noted with maca. However, more research in this area is needed.

+ Hormones

Macas hormone balancing effects may relate back to its amino acid content as follows; although hormones are very chemically diverse, they are constructed simply from amino acids and cholesterol. If the body is given the building blocks more readily, it is much easier to produce these hormones when they are needed.

It has been reported that maca does not activate androgen receptors [6], however, in ovariectomized rats, treatment with an ethanol extract over the course of 28 weeks was shown to produce support for postmenopausal symptoms related to hormones [7]. This conflicting evidence suggests hormonal effects are likely due to nutritional, or other means, rather than direct stimulation of androgen ergic system, or that the different durations of the two tests may have influenced the difference in results.

Other research, suggests that the hormone balancing effects maca has is through HP axis support, which in turn improves functions of the endocrine glands throughout the body [4].

The author suggests a combination between improvement of the HP axis function through alkaloids present within the plant, as well as an increase in amino acid, and cholesterol content needed to produce various neurotransmitters throughout the body. If this were the case, it would explain maca's adaptogenic effects, thyroid supportive effects, antidepressant effects, stress supportive effects, menopausal supportive effects, antidiabetic effects, and neuroprotective effects.

+ Menopause

A study investigating the effects of Lepidium meyenii on the hormonal levels in ovariectomized rats concluded that "Long-term Maca supply modulates endocrine hormone balance in OVX rats, especially it decreases enhanced FSH levels. It is proposed that maca may become a potential choice for postmenopausal women" [7].

Researchers refer to a previous study done by another group over the span of 6 weeks that noted no change in hormonal levels. They postulate that the longer duration of the experiment (28 weeks) that they conducted may have been responsible for the conflicting results. They determine that the mechanism in which maca is affecting hormone levels in ovariectomized rats is unknown during the time this study was conducted. This action is suggested to be the result of HPA axis support [4].

+ Neuroprotection

Gustavo F. Gonzales (2012) reports that "Black maca seems to improve experimental memory impairment induced by ovariectomy, orchidectomy, scopolamine, and alcohol due in part to by it's antioxidant and Ache inhibitory activities" (Page 4).

Other aspects that may provide neuroprotection may be result from the support maca alkaloids are suggested to have [4].

+ Thyroid Support

Maca alkaloids act upon the hypothalamus-pituitary axis, as this explains why its effects on endocrine glands are not limited to the ovaries or the testes, but instead on adrenals, thyroid, and pancreas as well as all endocrine glands throughout the body [4]. This is the suggested mechanism of action by these researchers for balancing female hormones post menopause (via ovariectomized mice).

If this is the case, the author suggests that improved thyroid health would most likely only be noticed in thyroid deficient people caused by low TSH rather than with a problem from the thyroid function itself. In other words, it appears maca does not "stimulate" the thyroid, but rather improves HP axis function, and thus thyroid function. Maca seems to be more adaptogenic in endocrine function than it is a stimulant for thyroid or metabolic functions.

 

Phytochemistry of Maca

Nutritionally, Maca has the highest nutritional value out of any food crop grown in the Peruvian Andes. It is rich in sugar, protein, starches, and essential nutrients (most notably iron and iodine) [8].

The main constituents include alkaloids, amino acids, beta-ecdysone, calcium, carbohydrates, fatty acids, glucosinolates, iron, magnesium, p-methoxybenzyl isothiocyanate, phosphorous, potassium, protein, saponins, sitosterols, stigmasterol, tannins, vitamin B1, vitamin B2, vitamin B12, vitamin C, vitamin E, and zinc.

Nutritional Summary Of Maca

Nutrient % Dried Weight Amount Per 5g Serving
Protein 10.2% 0.5g
Carbohydrates 59% 3g
Insoluble Fiber 8.5% 0.43g
Lipids 2.2% 0.18g

Chemical Breakdown

A more complete description of the composition of dry maca provided by Gustavo F. Gonzales (2012) shows 10.2% proteins, 59% carbohydrates, 2.2% lipids, and 8.5% of fibre.

Maca also contains free fatty acids including linoleic, palmitic, and oleic acids.

Saturated fatty acids represent 40.1% compared to unsaturated fatty acids which are 52.7%.

Maca contains amino acids (listed in mg/g protein) including:

  • Leucine (91.0mg)

  • Arginine (99.4mg)

  • Phenylalanine (55.3mg)

  • Lysine (54.3mg)

  • Glycine (68.30mg)

  • Alanine (63.1mg)

  • Valine (79.3mg)

  • Isoleucine (47.4mg)

  • Glutamic acid (156.5mg)

  • erine (50.4 mg)

  • Aspartic acid (91.7 mg)

  • Histidine (21.9 mg)

  • Threonine (33.1 mg)

  • Tyrosine (30.6 mg)

  • Methionine (28.0 mg)

  • Hydroxyproline (26 mg)

  • Proline (0.5 mg)

  • Sarcosine (0.70mg)

Maca is also rich in minerals including:

  • Iron (16.6 mg/100 g dry matter)

  • Calcium (150 mg/100 g dry matter)

  • Copper (5.9 mg/100 g dry matter)

  • Zinc (3.8 mg/100 g dry matter)

  • Potassium (2050 mg/100 g dry matter)

Secondary metabolites include macaridine, macaene, macamides [2].

 

Nutritional Breakdown of Maca

Nutrient Class Individual chemical Amount in mg/g
Protein Leucine 91
Arginine 99.4
Phenylalanine 55.3
Lysine 54.3
Glycine 68.3
Alanine 63.1
Valine 79.3
Isoleucine 47.4
Glutamic acid 156.5
Serine 50.4
Aspartic acid 91.7
Histidine 21.9
threonine 33.1
Tyrosine 30.6
Methionine 28
Hydroxyproline 26
Proline 0.5
Sarcosine 0.7
Minerals Iron 0.166
Calcium 0.15
Copper 0.06
Zinc 0.04
Potassium 20.5
 

Clinical Applications Of Maca:

In order to get the full benefits of maca, it needs to be consumed in high doses, on a regular basis, over long periods of time. It is a great supplemental herb for athletes, those seeking to improve libido, or to buffer overall stress resistance. It is also highly useful in this way for post-menopausal women to avoid symptoms, and slow the onset of related disease states such as depression and osteoporosis.

 

Cautions

Histidine may cause issues with allergies through histamine response.

It’s been reported that maca contains MTCA, which has been suggested to be toxic. However, this chemical is a natural component in many plants, including oranges, grapefruits, fermented garlic, and several other plants with which consumption is not associated with toxicity. Maca should not be considered toxic for this reason. Population studies have been conducted on maca as well, resulting in no toxicological indications from prolonged use of high dosages of maca as a nutritional agent [2].

No hepatotoxic effects, or general toxic effects, including in embryo development in mice, have been found associated with maca or maca extract [2].

 

Synergy

A randomized double-blind study done on 95 patients with osteoarthritis who were administered with a combination of Uncaria guianensis (300mg), and Maca(1500 mg), twice a day for 8 weeks, and reported substantial improvement in pain, and stiffness in the participants (broken source).

One study found synergy between Lepidium meyenii (Black maca), with Fragara tessmannii in the improvement of male reproductive organ activity [1].

 

Author

Justin Cooke, BHSc

The Sunlight Experiment

(Updated November 2018)

 

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References:

  1. Lembè, D. M., Gasco, M., & Gonzales, G. F. (2014). Synergistic effect of the hydroalcoholic extract from Lepidium meyenii (Brassicaceae) and Fagara tessmannii (Rutaceae) on male sexual organs and hormone level in rats. Pharmacognosy research6(1), 80.Chicago

  2. Gonzales, G. F. (2012). Ethnobiology and ethnopharmacology of Lepidium meyenii (Maca), a plant from the Peruvian highlands. Evidence-Based Complementary and Alternative Medicine, 2012.

  3. Meissner, H. O., Mscisz, A., Kedzia, B., Pisulewski, P., & Piatkowska, E. (2015). Peruvian Maca: Two Scientific Names Lepidium Meyenii Walpers and Lepidium Peruvianum Chacon–Are They Phytochemically-Synonymous?. International journal of biomedical science: IJBS, 11(1), 1.

  4. Meissner, H. O., Mrozikiewicz, P., Bobkiewicz-Kozlowska, T., Mscisz, A., Kedzia, B., Lowicka, A., ... & Barchia, I. (2006). Hormone-balancing effect of pre-gelatinized organic Maca (Lepidium peruvianum Chacon):(I) biochemical and pharmacodynamic study on Maca using clinical laboratory model on ovariectomized rats. International journal of biomedical science: IJBS, 2(3), 260.

  5. Rubio, J., Caldas, M., Dávila, S., Gasco, M., & Gonzales, G. F. (2006). Effect of three different cultivars of Lepidium meyenii (Maca) on learning and depression in ovariectomized mice. BMC complementary and alternative medicine, 6(1), 23.

  6. Chauhan, N. S., Sharma, V., Dixit, V. K., & Thakur, M. (2014). A review on plants used for improvement of sexual performance and virility. BioMed research international, 2014.

  7. Zhang, Y., Yu, L., Jin, W., & Ao, M. (2014). Effect of ethanolic extract of Lepidium meyenii Walp on serum hormone levels in ovariectomized rats. Indian journal of pharmacology, 46(4), 416.

  8. Taylor, L. (2005). The healing power of rainforest herbs. Raintree Nutrition Inc., Carson City, NV, 89701, 122-125.

  9. Mendes, F. R., & Carlini, E. A. (2007). Brazilian plants as possible adaptogens: an ethnopharmacological survey of books edited in Brazil. Journal of Ethnopharmacology, 109(3), 493-500.