The black mashua, whose scientific name is Tropaeolum tuberosum, is a tuber native to the highlands of the Andean region, which includes countries such as Peru, Bolivia, Ecuador, and Colombia. It belongs to the Tropaeolaceae family and stands out for its particular conical and sharp shape, whose size varies from 7 to 33 centimeters long.
It’s estimated that there are about 100 types of mashua, also known by names such as mashwa, bitter potato, cubio or majua. Its main difference is the color, as there are yellow, orange, brown, and a purple, almost black variety, which is the one we will discuss below.
Main characteristics of the black mashua
The black mashua is one of the rarest varieties of this tuber species. It usually grows in the Andean mountains, at 3000 to 4000 meters above sea level.
Its cultivation doesn’t require much care, and it reproduces easily and quickly. Hence the fact that it’s used in various culinary preparations.
The shape resembles that of the common potato or the Andean chuño; however, its skin is soft, firm, and waxy. The flesh maintains the purple tones so characteristic of this food.
When raw, its flavor is described as spicy and bitter. However, it acquires a slightly sweet taste when cooked.
- The plant as such emits a strong odor. In fact, it seems to function as a natural insect repellent. In Peru and other Andean countries, it’s often planted in gardens to ward off pests.
- It’s also the fourth most important tuber in the Andean region, after the potato, oca, and olluco.
Nutritional composition of black mashua
One of the reasons why mashua has gained recognition in its countries of origin is because of its nutritional value. Information disclosed through Galoá Proceedings details that the tuber contains protein, fiber, carbohydrates, and high levels of Vitamin C. In addition, it makes a small contribution of minerals such as iron, zinc, and manganese.
The amounts of these nutrients tend to vary according to the form and area of cultivation. To be a little more precise, a chapter of the book Bioactive potential of andean fruits, seeds, and tubers details that mashua tubers contain the following:
- Carbohydrates: between 69.7% and 85.8%
- Proteins: between 6.9% and 15.7%
- Fiber: between 4.8% and 8.6%
- Fat: between 0.1 % and 1.0 %
- Starch: 41.35%
This same document states that the insoluble fiber values reach 10.55%, which exceeds the contribution of other tubers, such as oca and olluco, which contribute 6.85% and 7.22% respectively. In addition, its total sugar content is 27.7%.
Meanwhile, the book Lost crops of the Incas: little-known plants of the Andes with promise for worldwide cultivation states that every 100 grams of dried specimens of these tubers provide the following:
- Calories: 371
- Total carbohydrates: 78.6 grams
- Protein: 11.4 grams
- Fiber: 5.7 grams
- Ashes: 5.7 grams
- Fat: 4.3 grams
- Calcium: 50 milligrams
- Phosphorus: 300 milligrams
- Iron: 8.6 milligrams
- Beta-carotene: 214 micrograms
- Thiamine: 0.43 milligrams
- Riboflavin: 0.57 milligrams
- Niacin: 4.3 milligrams
- Ascorbic acid (vitamin C): 476 milligrams
The International Journal of Food Science highlights that black mashua is one of the tubers with the highest vitamin C content. It should also be noted that the Tropaeolum tuberosum species is an abundant source of antioxidant substances.
Also, this study lists mashua as “a valuable natural source of phenols and anthocyanins with high antioxidant activity”.
Health Benefits of Black mashua (Tropaeolum tuberosum)
Due to its interesting nutritional value, the consumption of black mashua is associated with some health benefits. However, it should be noted that the evidence supporting its effects is still limited. What is known so far?
1. Antitumor potential
Black mashua supplements were long touted as ‘anti-cancer’ products. Due to the results of some research, the idea was spread that it could be a natural product for fighting cancer.
However, it’s important to clarify that it’s not an approved treatment against this disease.
Although the findings are promising, larger and more conclusive studies are lacking to corroborate its effects on human health. With that clear, let’s see what the research says.
An in vitro study by researchers published at the Journal of Ethnopharmacology found that an extract of black mashua exhibited cytotoxic and anti-inflammatory activity, suggesting its potential to support the treatment of cancer and diseases of inflammatory origin. Compounds such as flavonoids and polyphenols would be behind these effects.
In other research, reported in the journal Phytochemistry, two alkaloids isolated from the black tubers of Tropaeolum tuberosum were found to have the potential to kill cancer cells in lung, bladder, kidney and prostate cancer. Cytotoxic activity was also observed.
Meanwhile, an in vitro study shared by Biomedicine and Pharmacotherapy concluded that ethanolic extracts of black mashua, moringa, and custard apple have inhibitory properties on colorectal cancer cell lines. And while further studies are needed, they are believed to be future candidates for improved therapy against this form of cancer.
2. Natural diuretic
As a folk remedy, black mashua is used to promote the relief of fluid retention. Anecdotal data suggest that extracts of the plant increase diuresis (urine secretion), which in turn promotes de-inflammation.
However, there are not enough pharmacological studies to confirm these properties. In a study at the Universidad Peruana Unión, researchers observed a possible diuretic effect when using an aqueous extract of Tropaeolum tuberosum in mice. These effects are believed to be due to its content of tannins, anthocyanins, and flavonoids.
3. Cardiovascular health
Black mashua is one of the varieties of Tropaeolum tuberosum with the highest concentration of antioxidants. Scientific evidence has been able to corroborate its abundant content of phenolic compounds, tannins, anthocyanins, phytosterols, and fatty acids, which are key to the prevention of chronic diseases.
In terms of cardiovascular health, these substances help inhibit the negative effects of free radicals, involved in the onset of heart and cerebrovascular diseases.
4. Pain relief
In folk medicine, black mashua supplements are considered anti-inflammatory and analgesic. Because of this, they are used as a supplement to promote relief from various ailments. A review shared in the Journal of Ethnopharmacology cites its use against kidney and bladder pain.
In addition, because of its high concentration of anthocyanins, it’s believed to promote relief from cyclic breast pain, sports injuries, and pain associated with chronic inflammation.
5. Skin health
Consumption of black mashua is linked to several skin benefits. First, its abundant antioxidant content helps inhibit the negative effects of oxidative stress, a process related to premature aging.
These substances, together with their vitamin C content, also have positive effects on collagen production, which aids in the skin regeneration process. In this regard, studies in mice found that topical formulations of T. tuberosum have wound-healing activity.
6. Antihistamine potential
This tuber is used in traditional medicine as a remedy to soothe allergy symptoms. Although there are no concrete studies on these properties, it’s believed to be due to its high flavonoid content.
As stated in a study reported in Allergology International, adequate intake of flavonoids serves as a preventive strategy against allergic diseases. It has been observed that these substances help inhibit the release of histamine.
7. Antidiabetic effect
Anthocyanins, like other polyphenols present in black mashua, help inhibit enzymes involved in the digestion of carbohydrates. Thus, they are useful in regulating postprandial glycemic response (blood sugar levels after ingesting meals).
A 2019 study found that steamed black mashua tuber provides significant amounts of polyphenols, which confer anti-diabetic properties. Specifically, it helps modulate the absorption of sugars and oxidative stress.
Other uses of black mashua (Tropaeolum tuberosum)
The nutritional value and properties of black mashua have been valued by several ethnic groups that inhabit the Andes Mountain range. In these cultures, the tuber has been given other applications, beyond those just mentioned.
However, the evidence on its efficacy is insufficient.
For now, these uses are only supported by anecdotal data. They are detailed below:
- Kidney and liver health: it’s believed to help eliminate kidney stones and protect the liver against inflammation and fat accumulation. This is explained by the effects of its antioxidants. However, there are no studies to corroborate this.
- Remedy for anemia: in its countries of origin, black mashua is considered a supplement to promote the resolution of anemia, as it provides iron.
- Lice remedy: Black mashua root powder is applied to the scalp to help eliminate lice. A decoction of the tuber can also be used.
- Venereal and pulmonary infections: extracts of Tropaeolum tuberosum have antibacterial qualities that support the treatment of venereal and pulmonary infections.
Side effects and contraindications of black mashua
Consumption of black mashua is considered safe for most healthy adults. However, it’s believed that its long-term intake could cause fertility problems in men.
A study in mice suggests that mashua decreases their reproductive function by reducing the number and quality of sperm. However, research is needed to see if the same is true in humans.
On the other hand, its use is contraindicated in children, pregnant or breastfeeding women, as well as in patients with hypothyroidism and goiter. Nor is its simultaneous consumption with drugs for diabetes, arterial hypertension, anticoagulants, and antidepressants advised. In case of being under these treatments, it’s necessary to consult the doctor.
It should be noted that excessive amounts of this tuber are linked to dehydration and damage to the nervous system. For this reason, it’s suggested to consume it only 3 to 4 times a month.
Mode of consumption and presentations
Mashua is considered a versatile food, since it can be prepared in several ways. According to a publication of Peru Info, it can be eaten cooked, fried, in purees, in soups, in stews, and even as a dessert.
It can also be added to beverages. For this last purpose, it’s usually distributed in powdered form. It’s also available in capsules.
What to remember about black mashua (Tropaeolum tuberosum)?
Black mashua (Tropaeolum tuberosum) is a tuber native to the Andean region of South America. Like potatoes and other tubers, it has several gastronomic applications.
However, it also has a long history as a natural remedy for soothing pain, protecting cardiovascular health, and preventing diseases associated with inflammation. Due to its significant concentration of antioxidants, research has associated the use of its extracts with several health benefits.
Despite this, there is a need for more extensive studies in humans. Therefore, moderate consumption is suggested merely as a dietary supplement.