Maca (maca or Lepidium meyenii) belongs to the cruciferous vegetables and grows exclusively in the Peruvian Andes. The plant thrives at high altitudes (at 3,500-4,500 meters), in particularly harsh climates with strong sun, high temperatures during the day and low temperatures at night. The edible part of the plant is its root which is found in various colors such as white, yellow, pink, red and black. There are about 13 varieties but the most common is the yellow maca.
Although maca root was originally used as food, today it is consumed in powder form, as a dietary supplement – it is sometimes called Peruvian ginseng although both plants do not have any affinity. You can also find it in the form of a capsule or extract. It is an important export product for Peru.
Maca and nutritional value
Maca contains sufficient amounts of protein and fiber. Its powder contains 10-16% protein (as a percentage by weight), 59% carbohydrates, 2.2% lipids and 8.5% fiber. The most common amino acids it contains are leucine, arginine, glutamic acid and aspartic acid. 100 grams of maca contains vitamin C (8 mg), copper (150 mg), potassium (2,050 mg) vitamins B1 and B2, iron, zinc and manganese. Its different varieties may have somewhat different biological properties. For example, red and black maca have high levels of choline while red maca has high levels of GABA.
Maca and properties
Maca has been used for centuries for therapeutic purposes and mainly to enhance fertility and sexual drive. For example, it is used in animal husbandry to increase the fertility of animals. Scientific research confirms that maca may be effective in improving health and especially reproductive function.
- Improves male fertility
In men, maca increases fertility by improving both the quantity and quality of sperm. One study found that it increased sperm production in nine men . Another study showed increased sperm count in rats . It also increases sperm motility. Black maca and to a lesser extent yellow are the varieties that increase sperm count and motility – red may have no effect.
- Increases sexual desire
The plant is considered an aphrodisiac. One study showed that it increased sexual desire in men  while another study showed that it reduced sexual dysfunction in postmenopausal women . A 2010 review of four randomized clinical trials with a total of 131 participants found evidence that maca improves sexual desire after at least six weeks . However, this sample size is considered small and the average methodological quality of the studies was limited to draw solid conclusions.
Note that maca does not work through hormones and does not increase testosterone. It may increase estrogen in women but studies have shown mixed results.
- Relaxes and lowers blood pressure
There is evidence that maca boosts mood, relaxes and reduces stress. It also seems to lower blood pressure levels. A randomized, double-blind, placebo-controlled study included 29 postmenopausal women from Hong Kong. Participants received 3.3 g. daily or a placebo for six weeks and this was repeated for another six weeks by reversing the dosing regimen in both groups. Maca did not have a hormonal or immune effect but reduced the symptoms of depression and improved diastolic blood pressure . One explanation for the effect on blood pressure is that it contains a significant amount of potassium.
- It can enhance athletic performance
Maca root powder is a popular dietary supplement among athletes and bodybuilders. It is believed that it can help build muscle, increase strength and improve exercise performance. Studies in rodents have shown an improvement in their endurance . In addition, a small study of eight cyclists found that after 14 days of filling with maca extract, the completion time of a 40 km race improved. Another study showed that 80% of participants (175 people) reported improved mood and energy . There is no scientific evidence to support muscle mass or strength.
Maca and dosage
Doses of up to 3 grams per day appear to be safe when taken for up to 4 months. The dosage used in studies generally ranges from 1.5 to 5 grams per day.
Maca is easy to incorporate into your diet. You can start with a teaspoon (about 5 grams) to get used to the taste that not everyone likes – it has been characterized as earthy and dry. You can add a little powder to your coffee or tea. You can also add it to smoothies, oats, yogurt, milk, salads and recipes. Maca can be added to almost any dish and you can also make recipes with the main ingredient maca.
Maca and side effects
There are no reports of side effects after consuming maca as a food. However, the locals, in the highlands of Peru, suggest boiling maca before eating it. The traditional method of boiling up to 20 grams of powder to make juice has not been associated with toxicity. The boiling process seems to increase some metabolites but destroys other compounds -e.g. It is known that heating significantly reduces the content of vitamin C.
Side effects reported include impaired menstrual cycle, stomach cramps, discomfort and insomnia.
If you have thyroid problems, you need to be careful with maca because it contains substances that can affect the normal functioning of the gland. These compounds are more likely to affect you if you already have impaired thyroid function.
Maca contains a compound called MTCA and has the potential to cause DNA damage. In view of this risk, a French health organization said that consumers should be careful. This has been disputed by researchers who said that MTCA is inactivated during cooking. This substance is also present in other foods e.g. in oranges  and in some it is even found in a higher concentration than in maca.
The safety of taking maca supplements during pregnancy and lactation has not been evaluated.