Stevia is a plant from which an extract is obtained that can be used instead of sugar. It is an all-natural sweetener. With two advantages: zero calories and, unlike artificial sweeteners, no contraindications.
In Japan, stevia has been used for more than twenty years to sweeten foods and drinks. Chewing gum, dry foods and cereals, yoghurts and ice creams, teas, toothpastes and mouthwashes. Furthermore, they also use it for salty foods because it helps to mitigate the taste of salt (typical of the sweet and sour culture of oriental cuisine).
Contrary to sugar, stevia does not provide calories and behaves like dietary fiber. In fact, it is digested in the colon thanks to the metabolic activity of intestinal bacteria.
In addition to imparting the perception of sweet taste, the molecules extracted from stevia have a positive impact on glucose metabolism and are able to counteract the formation of plaques and cavities in the oral cavity.
Although the safety of its consumption has been much debated, to date it is considered scientifically safe. It is widely used as a sweetener in low-calorie diets and in the food industry as an ingredient in sweetened drinks and confectionery products (chewing gum, candies, etc.). The steviol glycosides extracted from it are recognized as food additives, with the initials E960, therefore, considered to all intents and purposes a food from a legislative point of view.
Stevia: what is it
Stevia Rebaudiana Bertoni is a perennial plant that belongs to the Asteraceae (or Compositae) family.
It is native to South America where it grows spontaneously. More than 150 species of the Stevia genus have been described, but Rebaudiana Bertoni is the only one characterized by a strong sweetening power.
In fact, glycosides responsible for the sweet taste can be extracted from its leaves, which have the advantage of not adding calories. These are found on the market as natural sweeteners (indicated with the initials E960), in mixtures containing purified glycosides, stevioside and rebaudoside.
- Domain: Eukaryota.
- Kingdom: Plants.
- Classe: Magnoliopsida.
- Subclass: Asteridae.
- Order: Asterales.
- Family: Asteraceae.
- Kind: Stevia.
- Species: S. rebaudiana.
Is it a safe product?
In America and in the other countries of the European Union, the use of stevia remained prohibited until 2011.
Since, in 1999, the Commission on Food Additives of the WHO and the Scientific Committee for Food of the European Union gave a negative opinion on its use. In fact, it was believed that steviol, a metabolite of substances present in stevia, could be carcinogenic.
After years of studies, in 2004, researchers from the Belgian University of Leuven organized an international symposium, “The safety of stevioside“. It ended with a certainty: stevia is a safe product. Thus, the WHO has also revised its opinion, especially on the basis of the results from countries where stevia has been used for years.
Since 2 December 2011, the EFSA (European Food Safety Authority) has also given the green light to the use of stevia in the European Union, and therefore also in America.
Now you can buy stevia-based sweeteners. No contraindications or side effects have been reported so far.
Studies conducted on animals to verify the possible toxicity and to identify the lethal dose have ascertained that it is a dose so high as to be almost impossible to reach. And even prolonged use presents no problems.
Stevia: properties and benefits
It is about 150 times more potent sweetener than sucrose. But not being composed of absorbable sugars, it does not provide calories. It’s a blend of two sugars, stevioside and rebaudioside, and comes from a plant, so it’s an all-natural sugar.
Stevia leaves are rich in nutraceutical compounds of great nutritional value (primarily steviol glycosides) which bring numerous benefits to the body.
It has a positive impact on glucose homeostasis
Stevioside and other steviol glycosides are able to reduce the glycemic index (blood glucose concentration), acting on several fronts.
They regulate glucose uptake
They act on pancreatic beta cells, increasing the secretion of insulin (molecule capable of subtracting glucose from the blood district to store it in the cells, as an energy reserve).
At the same time, they are able to regulate the activity of pancreatic alpha cells, reducing the production of glucagon (the enzyme antagonist of insulin).
In this way, stevia shifts homeostasis in favor of glucose utilization.
Reduce gluconeogenesis (endogenous glucose synthesis)
They exert their action directly, slowing down the expression of a gene involved upstream of the glucose biosynthetic pathway (PEPCK gene).
They increase insulin sensitivity
They are able to activate the glut1 transporter (glut4 isoform), increasing the uptake of glucose into cells. This mechanism increases the sensitivity of the insulin receptor, facilitating glucose uptake indirectly.
Stevia helps in weight recovery
Stevia is a functional ingredient that can help as a sweetener in low-calorie diets such as the Tipsforwomens diet. In fact, it has a double advantage: it is able to satisfy the desire for sugar without adding calories. Furthermore, it has a direct action on glucose metabolism.
It has anti-inflammatory action
Stevioside, contained in stevia leaves, is able to modulate the action of an important transcription factor (NF-kB) involved in the mechanisms of response to cell damage and tissue inflammation.
Regulates blood pressure
In conditions of hypertension (blood pressure levels greater than or equal to 90 mmHg, diastolic, and 140 mmHg, systolic) stevia leaves can be used as a cardiac tonic, for:
- normalize blood pressure levels
- regulate the heartbeat and for other complications related to the cardiovascular system.
They go to act at the level of cell membranes by blocking calcium channels. This action has a direct effect on the walls of the arteries, relaxing the muscles and reducing blood pressure.
Reduces cholesterol
A regular intake of stevia can facilitate a reduction of LDL cholesterol and triglycerides in the blood, while increasing the levels of HDL lipoproteins (“good” cholesterol, useful for cellular metabolism).
Stimulates kidney functions
Steviol glycosides have a diuretic effect. The action of steviol glycosides on the calcium channels determines the vasodilation of the afferent arterioles (those that carry blood to the kidney). It follows an increase in glomerular filtration and, consequently, an increase in diuresis.
Counteracts the onset of caries
The consumption of simple sugars has always been correlated with the increase in the incidence of dental caries. Using stevia instead is, in this sense, preventive.
Fights cellular aging
Thanks to the presence of flavonoids and other nutraceutical elements with an antioxidant value, stevia is able to counteract the action of free radicals, the main causes of cellular ageing.
Hence, it is useful for skin care, effective against acne and skin blemishes.
Stevia is recommended in case of candidiasis
Candidiasis is an infection caused by the fungus Candida albicans. It is a very frequent condition, especially in women, which can be prevented or eradicated with the help of a diet devoid of simple sugars.
The use of stevia in place of sucrose is advisable in this condition.
Relieves symptoms of intestinal disorders
Polyphenols and steviol glycosides exert an anti-inflammatory effect on colon cells, capable of inhibiting spasms and muscle contraction, limiting disorders related to irritable bowel syndrome (IBD), episodes of diarrhea and abdominal pain.
Stevia: contraindications
The safety of using stevia has been much debated for years due to the chemical nature of its components.
Steviol and steviol glycosides have an easily reactive hydroxyl group (OH) and potentially capable of generating an epoxy derivative. Epoxides are highly reactive molecules, considered genotoxic, as they are able to interfere with the nitrogenous bases of DNA.
Toxicological studies have shown that the secondary metabolites present in stevia have no teratogenic, mutagenic, genotoxic or carcinogenic effects on humans. Furthermore, the scientific studies conducted have not reported any correlation with the malfunction of the human reproductive system or the growth retardation in children.
Therefore, stevia consumption has been assessed as safe in normal doses of use, even for prolonged periods.
Instead, if taken in high doses, stevia could cause:
- Hypotension.
- Hypoglycemia.
- Laxative effect.
Stevia: nutritional values and calories
Stevia is a herb rich in nutrients:
- water
- Amino acids.
- Fibre.
- Sugars.
- Lipids.
- Mineral salts (in particular, magnesium, iron, potassium and phosphorus).
- B vitamins.
- Ascorbic acid (vitamin C).
- Beta carotene (precursor of vitamin A).
In addition, it contains a good amount of aromatic compounds, flavonoids and essential oils:
- apigenina.
- Quercetin.
- Isoquercitrin.
- Luteolina.
- Miocene.
- Campferolo.
- Stigmasterolo.
- Xanthophyllus.
- Umbelliferone.
- Chlorophenic acid.
- Caffeic acid, etc.
The leaves have about 2.7 kcal/g of dry matter, although it is more common to consume the purified glycosides (extracted from…
