**6. Effect of nutritional physiology**

The results of pharmacological studies performed by several researchers confirm that beetroots can be used effectively and advantageously in the treatment of various diseases [17]. Betacyanins found in large quantities in beetroots counteract the harmful effects of oxidative stress and free radicals, have antibacterial and antiviral properties, inhibit the proliferation of cancer cells, and are involved in the prevention of cardiovascular disease [29, 60]. Because beetroots have many properties that have a positive effect on the human body, it has also become known as an herb. In addition, beetroots also have anti-inflammatory and hepatoprotective effects [61].

Its role in folk medicine is of great importance. A decoction made from the seeds of a vegetable has been used to treat intestinal and genital tumors. Beetroot juice has been thought to help fight tumors, leukemia, or other types of cancer. Among some of the components of the juice, betacyanins play an important role in inhibiting the metabolism of cancer cells. In addition, two very important components of amines are still present: choline and its oxidized form, betaine, in the absence of which experimental results have shown that tumors in the mice body have developed more likely [62].

VÁLI et al. [35] investigated the hepatoprotective properties of beetroot bioactive substances in a rat model of ischemia-reperfusion injury. As a result of feeding, global liver parameters and enzymatic antioxidants (glutathione peroxidase and superoxide dismutase) were significantly increased, indicating a positive effect of treatment. The results show that a diet rich in natural antioxidants has a positive effect on redox homeostasis during hepatic ischemia-reperfusion injury.

A colorant called betanin is known to have primarily lymphatic tumor inhibitor and antihypertensive effects. The proof of its antitumor effect is due to Sándor Ferenczi, who discovered in 1961 in animal experiments that the betanin colorant acts against cancer cells. He advised his patients to consume 1 liter of squeezed beetroot juice daily for 3 months, which not only works against cancer cells but also improves blood counts. In addition, next to Ferenczi, Rudolf Breuss the naturopath also recommended consuming 2.5−3 liters of beetroot, potato, celery, radish, and carrot juice. He discovered that this juice fasting cure helps to suppress tumor cells [63]. NYIRÁDY et al. [64] administered a commercially available natural beetroot preparation in a dose of 2 × 10 g to 24 patients with hormone-resistant and metastatic prostate cancer receiving taxane chemotherapy for 1 month to improve the quality of life. Their results showed that in the vast majority of patients, beetroots had a beneficial effect, and significantly high levels of Zn and free protoporphyrin in tumor patients were reduced, and transmethylation processes were accelerated.

Consumption of beetroots due to their high betanin content can cause beeturia (red urine) and red feces in people who are unable to degrade [65, 66]. The interest of the food industry towards betalaines has increased as they may provide protection against oxidation of low-density lipoproteins [67].

Like many other colorful vegetables, beetroots are considered an antioxidant gold mine [3, 68]. FIDELIS et al. [69] showed that beetroot juice (pH 5.45, 9°Brix) has higher total phenol (1169 mg GAE/l), flavonoid (925 mg catechin equivalent/l), and pigment content (854 mg/l) than citrus fruits, yellow passion fruit, apples and blueberries, which also results in a better antioxidant profile (325 mg AAE/l). WOOTTON-BEARD and RYAN [70] found that betanin and aglycone betanidine

have extremely high antioxidant activity, which has been shown to be effective in preventing lipid peroxidation [38].

Beetroot contains a number of bioactive compounds, which result natural antianemic, anti-inflammatory, antihypertensive, anti-cancer, antipyretic, antibacterial, detoxifying and diuretic properties [34, 71], as well as stimulating the immune system, and liver protection [72]. SLAVOV et al. [61] demonstrated that betalain pigments play a role in the chemoprevention of lung and skin cancer and inhibit cell proliferation of various human tumor cells. IGLESIAS et al. [73] have also proved their anti-cancer effects and slightly reduce the inflammatory response and modulate the immune response.

Nitrates present in beetroots are able to lower blood pressure, protect against ischemic reperfusion injury and modulation of mitochondrial function [74], and reduce bad cholesterol [29]. NINFALI and ANGELINO [8] also report the antihypertensive effect and hypoglycemic activity of beetroot extracts. A study by MONTEIRO and AZEVEDO [75] found that regular consumption of beetroots reduces the risk of inflammation (instinctive reaction, including infection, erythema, edema, trauma, fever, and cell damage caused by pain).

Beetroots are healthy food for the entire digestive system. The water, in which the beetroots are cooked, can be used to treat skin infections, acne, and ulcers [76]. Beetroot juice helps clean the blood, regenerate and reactivate red blood cells, and provide the body with fresh oxygen [77]. The copper content of beetroots promotes the absorption of iron. Beetroot can also be used to treat fever and constipation [13].
