Q&A: Artificial Sweeteners

Artificial sweeteners are a controversial topic, and something we get asked about a lot in relation to diet and cutting weight. This is a nice summary of the evidence by David Chalton PhD. 

Let’s get one thing straight right at the start. We’re not saying artificial sweeteners are an essential part of your diet. We’re not saying that you should have them. Some people prefer to avoid them for whatever reason, and that’s fine. However if your goal is to first reduce, then eliminate sugar sweetened beverages from your diet, then they can sometimes play a useful role.

It’s not too controversial to say drinking 4 litres of cola a day is bad for you (about 1700 kcals). Swapping it for 4 litres of diet cola (about 16 kcals) is better. Drinking your calories causes problems. Not only are you chugging down most of your daily allowance, but you’ll also tend to underestimate how much sugar you’ve actually had, leading to overeating. There are also other reasons to think that processed sugars may be one of the most significant dietary risk factors for a variety of health problems.

So what are Artificial Sweeteners?

The food industry likes to call them non-nutritive sweeteners. They are substances that are incredibly sweet, so sweet in fact that you only need really small amounts to make something taste sweet.

A regular can of cola contains about 39g of sugar (that’s about 10 teaspoons) if we used the same weight of aspartame (a commonly used sweetener in soft drinks) how many similarly sweet diet cola 330 ml cans could we make? Each can of diet cola contains around 0.18 g of aspartame

So we could make 216 cans and a half empty one!

The European Food Safety Agency has recommended maximum intake of 40 milligrams of aspartame per kilogram of bodyweight. So if you weigh 50 kilos you can safely consume 2 g of aspartame, that’s slightly over 10 cans. If you weigh 100 kilos you can safely consume slightly over 20 cans. But why would you?

Hold on! ‘Maximum intakes’? Doesn’t that mean they’re dangerous?

The short answer is no under normal consumption (but see the next section). A lot of internet search results will provide people’s own opinions on artificial sweeteners. Some of these are exceptionally dramatic, which tends to attract more attention than dull scientific facts. Controversy can be good business!

The most ‘controversial’ sweetener is probably aspartame, which has been blamed by various people at various times for a whole bunch of diseases, including Alzheimer’s disease, birth defects, diabetes, Gulf War syndrome, attention deficit disorders, Parkinson’s disease, lupus, multiple sclerosis and seizures. Phew!

Before flying into a panic and throwing out the kids’ sugar free squash, let’s look more closely at the evidence.

Aspartame is simply two amino acids linked together, in a way that makes them taste really sweet. Once you’ve drank the 0.18g of aspartame in a diet drink, they are broken down into their constituent amino acids; aspartic acid and phenylalanine (just like milk, which provides more phenylalanine and aspartic acid than diet cola).

So any web hoax/‘warning’ about aspartame that uses highly technical language to confuse you about how “it is the only substance that can pass the blood brain barrier and destroy the brain!” and cause a whole host of nasty diseases is wrong. In fact one of the initial pieces of research showed that if a 50 kg person drank the equivalent aspartame present in 56 cans of diet cola all at once (0.2g aspartame per kg of body weight) there would be ZERO aspartame in their bloodstream.

Most of the existing rumours about Aspartame can be traced back to a specific internet hoax in the 1990s, which picked up such unquestioning support from conspiracy theorists the US FDA felt it necessary to issue a statement dismissing the hoax.

The UK Scientific Committee on Food has reviewed over 500 scientific papers on the safety of aspartame.

But why do Aspartame containing products have a ‘Warning Label?’

A very small number of people (about 1 in 10,000) have an inborn error of metabolism, called Phenylketonuria (PKU). These people cannot metabolise the amino acid phenylalanine, (present in aspartame). This has nothing to do with aspartame itself.

A test has been performed in the UK during the first week after birth routinely since 1969 to diagnose PKU, as a prescribed diet during childhood, low in protein can help minimize any long term health problems from this genetic condition.

So important is the childhood diet, that it is a legal requirement (in the UK) to label aspartame containing products to make people aware of the phenylalanine content. But unless you or a family member have PKU (and if that’s the case, you’ll know about it), it’s not something you need to worry about.

I saw a report that diet drinks are associated with depression! That doesn’t sound good!

There are various studies that show an association between consumption of diet drinks and certain diseases. The trouble with this research is that it’s based on observations of what people do in real life. Real life is messy, and there are many different factors to take into consideration. What these studies show is not that diet drinks cause disease, but that people who choose diet drinks are more likely to suffer from certain conditions. That’s a whole different thing. (In scientific terms, a correlation doesn’t prove causation). In this case, a very plausible explanation for the results is that people who are on a low calorie diet are both more likely to drink diet drinks, and to be depressed. When you look at it this way, it would be more surprising if there wasn’t a link!

Action Plan:

•  If you are regularly drinking sugar sweetened soft drinks, aim to make your first step getting rid of them.
• Either swap them for diet versions, or if you prefer to avoid sweeteners, then try swapping them for sparkling water, tea, coffee, tap water. Essentially anything, apart from alcohol containing beverages!
• Adding a bit of lemon to sparkling water, might help give that bit of acid ‘zing’ you are used to in commercially produced drink.

A caveat

Switching from sugary drinks to low sugar versions will only have a positive effect if you’re not increasing your sugar intake elsewhere in your diet. Some research seems to indicate that people who choose diet drinks are more likely to reward themselves with sugary snacks – cancelling out the benefits from switching.

“Low-calorie sweeteners, including Aspartame are among the most comprehensively investigated food additives ever, and have been assessed by national and international regulatory bodies throughout the world, in all cases they have concluded that Aspartame is safe.” UK NHS