Exploring the various types of artificial sweeteners, and the additives used to glaze foods

The industry recommended daily limit for aspartame consumption is 2,400mg. PHOTO: STEVE SNODGRASS/WIKICOMMONS
The industry recommended daily limit for aspartame consumption is 2,400mg. PHOTO: STEVE SNODGRASS/WIKICOMMONS

(THE STAR/ANN) - The artificial sweetener, E951 (aspartame) is ubiquitous in food items and the focus of much controversy.

Food regulators in the United States and the European Union assert that aspartame is a non-toxic compound – so how come there is so much controversy?

Well, there have been many odd events in the life of this compound (developed by G. D. Searle & Co) since it first gained approval in 1974 for use as a sweetener additive by the Food & Drugs Agency (FDA) in the United States.

However, this approval was rescinded late in 1975 due to highly questionable issues with the safety studies submitted by G. D. Searle & Co.

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 In May 1981, three out of six scientists at the FDA advised against approving aspartame, but in July the same year, the FDA commissioner ignored their concerns and unilaterally approved aspartame for use in dry foods.

This was followed by approval in July 1983 for aspartame use in carbonated drinks and syrups.

Even after approval, various steps were taken to establish the toxicity of aspartame, culminating in the FDA releasing a list in 1992 of over 8,000 complaints categorised by various reported symptoms.

Still, the advice was that aspartame is safe, except for people with phenylketonuria (a rare condition where sufferers cannot metabolise phenylalanine).

Then various European studies appeared to provide contradictory evidence. Tsakiris (2005) reported neurological issues with aspartame consumption by humans within the consumption limits recommended by the FDA – mostly it was related to learning impairment and memory loss.

Even earlier, a study by Trocho (aka Barcelona Study, 1998) had implicated aspartame in both organ and brain damage in test rats.

But possibly the most worrying reports were the 2005 Soffritti Study which claimed that aspartame is a carcinogen in test rats – and this claim was subsequently supported by another study by Ramazzini in 2007.

The case against aspartame was really not helped by a fake letter circulated in 1999 by a supposed “Nancy Markle” which claimed that the compound was responsible for multiple sclerosis, systemic lupus, and methanol toxicity, causing “blindness, spasms, shooting pains, seizures, headaches, depression, anxiety, memory loss, birth defects and death”. The false claims were easily disproved and led to justifiable accusations of a smear campaign against aspartame.

Regardless of the politics, the facts are quite simple. Aspartame is manufactured using the waste by-products of genetically-modified Escherichia coli bacteria breeding in warm tanks of carbohydrates, nitrogen compounds and other nutrients – however, medical insulin is also produced in a similar manner so this is not necessarily contentious.

 

When ingested, aspartame decomposes into two amino acids (40 per cent aspartic acid and 50 per cent phenylalanine) and 10 per cent methanol. Aspartic acid can be manufactured by the body itself but diet is the only source of phenylalanine    

 

(which is used as a precursor for dopamine, norepinephrine and epinephrine). Methanol is a toxic compound and is broken down first in the liver into formaldehyde (also toxic), and then into formic acid (yet another toxic compound) before finally

 

being detoxified into carbon dioxide.

Before you worry too much, methanol is a very common compound also found in fruits, vegetables, beers, et cetera – so this compound is not necessarily substantially contentious either, especially as the overall methanol load from normal consumption of aspartame is quite low.

What is curious is that there is some evidence that both dietary aspartic acid and phenylalanine can cross the Blood-Brain Barrier (BBB), and can therefore affect the brain.

The problem is that normal diets with common foods (eg. fish, meat, legumes, corn, soy-based foods, et cetera) have lots of the same amino acids – and fruits, vegetables, beers, wines, et cetera, contain methanol, so eating standard healthy meals might also be a bit risky if aspartame is indeed acutely toxic.

Also, many of the problematic test results involved rodents as test subjects – not humans, whose physiology is significantly different.

However, the human processing of large amounts of aspartame via carbonated drinks may enhance the uptake of aspartic acid and phenylalanine, not unlike people getting drunk faster with sparkling wines (because the bubbles induce a faster absorption of alcohol) – though no research has established yet whether this is of any relevance.

Perhaps more relevant is a 2015 study which showed that glucose intolerance in rodents and some humans can be induced by artificial sweeteners altering the balance of bacterial colonies in the gut microbiome.

The theory is that the low-calorie sweeteners favour proliferation of the bacteria that are better at extracting energy (ie. glucose) from food – this extra glucose finds its way into blood and body tissue where it promotes insulin resistance, which can eventually lead to health issues like obesity, diabetes and diseases of the liver and heart.

However, on balance, the evidence still suggests that aspartame itself is not toxic, especially if ingested and buffered with other foods – so perhaps do not drink a litre of diet soda at once without proper food.

In any case, there are no compelling medical or health reasons to ingest aspartame at all, so if you want to be safe, perhaps a sensible course of action might be to limit consumption to, say, a quarter of the Acceptable Daily Intake (ADI) of 40mg per kilo of body weight.

This means if your weight is 60kg, the industry recommended daily limit for aspartame consumption is 60 x 40 = 2,400mg – or if you want to be safe, 600 mg a day. Aspartame is 200 times sweeter than sucrose so a quarter of the ADI at 600mg is still equivalent to an amazing 120 grams (or over quarter of a pound) of sugar.

For reference, a single 330ml can of diet cola can contain 175mg of aspartame.

Even though it is heavily abridged, the overview of E951 above is important not only due to the many unusual scientific controversies over its use – but because there are also other less well-known, equally strident disputes about the safety of many other EU-approved sweeteners such as E950 (acesulfame K), E952 (cyclamic acids), E953 (isomalt), E954 (saccharins), E955 (sucralose), E957 (thaumatin), E959 (neohesperidine DC), E960 (steviol glycoside), E961 (neotame), E962 (salt of aspartame-acesulfame), E964 (polyglycitol syrup), E965 (maltitol), E966 (lactitol), E967 (xylitol), E968 (erythritol) and E969 (advantame).

Of the list above, both E961 and E969 are notably interesting as they are a new breed of super high-intensity sweeteners – neotame is around 9,000 times sweeter than sugar and advantame is an incredible 20,000 times sweeter.

E960 is a natural sweetener derived from the leaves of the Stevia Rebaudiana plant and is about 250 times sweeter than sugar – and research has currently found scant evidence of toxicity in the human use of steviol glycoside.

However, if you attempt to buy this rather expensive compound in the supermarkets, many of the packaged stevia-based sweeteners are substantially adulterated with other synthetic sweeteners – so please be aware of this. It seems that additives are even added to other additives now.

The high use and low cost of artificial sweeteners (and indeed sugar itself) means that it has been suggested that modern processed foods can taste around three times as sweet as similar foods only 50-odd years ago.

The per capita use of natural sugar itself has gone up 30 per cent between 1977 and 2010 in the United States – and consumption of High-Fructose Corn Syrup (HFCS) there has gone up 245 per cent between 1989 and 2000 alone.

The consumption statistics of artificial sweeteners is not easy to derive given the range of chemicals, producers and uses – but it would be reasonable to assume that the usage of artificial sweeteners has been on a pretty steep upward trend for the last few decades.

For example, in 2014, around 32 per cent of Americans routinely choose to consume artificial sweeteners on a daily basis.

Note that sweeteners are often used to mask the bitterness of other additives – and therefore many societies have generally grown accustomed to the extravagant sweetness of modern processed foods. Think of “honey-cured” meats, caffeine-laden canned drinks or frappucinos, for example.

There are some other curious additives in the E9xx section – and we will start with E900 (dimethylpolysiloxane). In real life, E900 is a compound used to make the silly putty children play with – but it is also used as an additive to frozen French fries and other commercial deep frozen fried foods.

This is because its strong anti-foaming properties help prevent hot oil from splashing or bubbling over when cooking, especially in large commercial deep fat fryers.

How it works is because this silicone compound has a relatively low surface tension and can therefore flow easily onto the external films of hot oil bubbles – once there, E900 acts as a surfactant to reduce the surface tension of the oil bubbles and also weaken the surfaces in between adjoining oil bubbles, causing them to fold gently back into the hot oil.

E901 (beeswax), E903 (carnauba wax), E904 (shellac), E905 (paraffin or microcrystalline wax) and E907 (hydrogenated poly-1-decene) are glazing agents, used to make sweets, fruits, confectionaries, medicine pills, et cetera, externally shiny. For example, the use of E901 and E903 is how chocolate Smarties get that attractive bright, polished look.

E913 (lanolin) is derived from the oily secretions from the sebaceous glands in the hides of sheep – these secretions are used to oil wool, and apparently often included as part of the gum base for use in chewing gums (though most of the gum base is made from other compounds). Lanolin is also used in cosmetics and bath soaps as a moisturiser.

If chewing on E913 now sounds a little icky, then consider the origins of E920 (l-cysteine) – it is a dough conditioner commonly used to ensure commercial breads remain soft and fluffy long after they have been baked.

E920 was originally derived from human hair though it can also be extracted from bird feathers and animal hairs – in the EU, E920 sourced from human hair cannot be used.

However, in China it seems that much of the E920 produced there is still based at least in part on using human or pig hair – there is no way to test for the origin because the molecules are homogenous after processing into l-cysteine. China is a major exporter of l-cysteine to the world.

E927 (azodicarbonamide) was famous a few years ago for its dual use in making yoga mats and improving the textures of bread rolls in some popular food chains – but it is now banned in the EU.

However, E927b (carbamide) is still permitted as an additive to improve the colour and baking quality of flour. A more common term for carbamide is urea, though of course the urea used in baking is not derived from human or animal waste.

Gases are also considered additives, though it would be rare to see them listed on a supermarket label as they are usually exhibited only for commercial bulk packaging – E938 (argon), E939 (helium) and E941 (nitrogen) are used as packaging gases to prevent the spoilage of food; E942 (nitrous oxide) is used as a spray propellant for other additives and oils; E943a (butane), E943b (iso-butane) and E944 (propane) are used as flammable gases to char or singe surfaces to finish the presentation of foods such as creme brulee, moussaka, lasagna, et cetera; E948 (oxygen) is used to oxidise food quickly to obtain a matured or aged look; and E949 (hydrogen) is used to hydrogenate fats.
The last of the E9xx series is E999 (quillaia extract) which is used commonly as a foaming agent to improve the bubbles in beer and other fizzy drinks – it is also a natural humectant, often used to keep cakes, puddings and other desserts moist for extended periods of time.

Yet again, I have to add that over-consumption of many additives may lead to possible health hazards and side effects – and it is simply not possible to cover all potential reactions due to the numbers and combinations of additives.

However, most food additives are regulated in their use and therefore should not cause problems when processed foods are consumed in reasonable amounts by healthy humans.