Refined sugar has long been known to be extremely harmful in the diet. However, we do like the sweet taste in our drinks and foods. In addition many foods simply do not taste good without added sweeteners, especially low fat products. All this has caused the consumption of the artificial sweetener aspartame to skyrocket. It is now found in 6000 products including health supplements. Only now are people beginning to realise that aspartame is not a healthy option. The bad health effects outweigh those of sugar itself. Luckily there is an all natural, zero calorie alternative to both sugar and aspartame, that not only will make your food taste good, but is actually good for you- stevia.


Aspartame is the most commonly used artificial sweetener. It is made by chemically linking two amino acids, aspartic acid and phenylalanine, and methanol. The resulting dipeptide is hundreds of times sweeter than sugar, so the amount used to achieve a sweet taste has negligible calories. In the body aspartame is broken down to its constituent amino acids, and to methanol. Although methanol is a known toxin, the proponents of aspartame argue that it is produced in amounts that are too low to affect health. In humans the methanol is metabolised to produce formaldehyde, which can then function to cross link proteins.

The safety of artificial sweeteners is a matter of big debate. A range of studies in both animals and humans exist, with quite conflicting results. A sad fact of life is that the food industry wields immense lobbying power, and can unduly influence regulatory bodies to pass food additives without sufficient testing.

The most worrying aspects of aspartame are several animal studies that link the artificial sweetener to increased risk of developing cancer in rats. The first such study to raise concerns was done in 1970, it showed that aspartame increases the risk of developing brain tumours. Initially the independent FDA review panel concluded that aspartame was not safe for human consumption, but later they reversed their opinion. In another study, a team working in the Ramazzini Foundation in Bologna, Italy, studied the effects of different doses of aspartate on 1800 rats, from 8 weeks of age till their natural death. After death the animals were autopsied to determine the cause of death. The team discovered that the animals that were exposed to aspartame had an increased rate of leukaemias, lymphomas, kidney, and brain cancers. This is just one of the studies by independent scientists that concluded that aspartame increased the risk of developing tumours.

The FDA and its European equivalent criticised the methodologies of these studies, arguing that leaving the animals to die naturally invalidated the results. But other scientists do not share these concerns and think that the reason that the study found an increased risk of cancer where other animal studies didn’t is because it used many more animals and allowed them to live longer. Most animal studies in rats only study the animals for two years. A two years old rat is equivalent to a 65 years old human.

The same Bologna team published another rat study in 2007 starting the exposure while the animals were still in the womb, and another study in 2010 using mice. Both of these studies concluded that aspartame increases the risk of cancer in animals.

A human study by scientists from the Harvard University School of Public Health found an increased cancer risk from aspartame in men but not in women. The researchers hypothesised that the difference might be due to the higher levels of the enzyme that turns methanol into formaldehyde in men.

The American Centre for Science in the Public Interest, a non-profit organisation, states that in view of these studies, the FDA should reverse its opinion on aspartame, and the sugar substitute should be withdrawn from the market at least until more studies are carried out.


The other worry with aspartame is that one of its products in the body is aspartic acid. This amino acid not only acts as a building block for proteins, but also functions in the brain as an excitatory neurotransmitter. Some experts worry that it can lead to cytotoxicity, a pathological phenomenon in which neurons that receive too many excitatory signals are damaged, and can die.

Of the more than 10,000 reports submitted to the FDA by consumers, neurological symptoms predominate. By far the most frequently cited adverse reaction was migraine headache, but more serious effects such as dizziness, and even hallucinations. In total consumers complained of 92 different symptoms to the FDA.


Stevia is a leafy shrub that grows in South America, and had been used there to sweeten foods and beverages and for its medicinal properties for centuries. It contains two phytochemicals, stevioside and rebaudioside, that are much sweeter than sucrose (sugar).

Not only is Stevia natural and considered completely safe, but it comes with some important beneficial effects on health. One of those is that it appears to lower blood pressure. As almost everybody knows, high blood pressure is dangerous, increasing the risk of heart disease, kidney disease and stroke. A double blind, placebo controlled, randomised study in China, looked at the effects of Stevia on the blood pressure in 175 patients with mild hypertension over two years, and concluded that Stevia has a significant beneficial effect. The natural sweetener also decreased the risk of right ventricular hypertrophy, a type of heart disease caused by high blood pressure.

Another study on the effects of stevia showed that it, or rather stevioside, one of the sweet compounds in stevia, shows that it can improve glucose metabolism, and might be used in the treatment of people with type II diabetes. Type II diabetes is an acquired insensitivity to insulin, or inability to produce the hormone, and is reaching epidemic proportions in the UK and the US. A study in mouse showed that stevioside enhanced the secretion of insulin from the pancreas in the presence of glucose. Another study in rats showed that stevioside increases insulin sensitivity. Although some of these studies are done in animals, and others have only a small number of participants, the preliminary data is very encouraging.

Given all the above, which sugar substitute, do you think you prefer? On the one hand we have aspartame, an artificial sweetener, which three animal studies, and one human study link to an increased risk of cancer, and which caused neurological symptoms in thousands of people. On the other hand, there is stevia, a natural botanical extract, which not only hasn’t had any negative side effects associated with it, but also may lower blood pressure and blood glucose levels. I think the choice is very simple!


The first study finding carcinogenic effects of aspartame in rats:

The second study on the effects of low doses of aspartame and cancer risk in rats:

Aspartame induces cancers in mice:

Harvard School of Public Health study on aspartame and the risk of leukaemia:

Stevia lowers blood pressure:

Stevioside lowers glucose levels in patients with type II diabetes:

Stevioside increases insulin sensitivity in rats: