Tuesday, October 29, 2013

Sweetening agents 2

There is nothing quite like commenting on sweetening agents to generate a response, often quite emotional. A couple of comments that are suitable for publication are reproduced in the letters section below. If I say something positive about a sweetener, especially aspartame, then someone will want to disagree. Let’s be honest, there are far more negative than positive comments about “artificial sweeteners” on the internet.
One enduring concern is that sweeteners cause cancer. This has been refuted by the Cancer Council and the famous Mayo Clinic and others, but maybe they are all working in collusion.

500 year old advice still relevant
Last month I attended the International Union of Nutrition Science conference in Spain. There I met Sir Andrew Renwick, Professor of Medicine at the University of Southampton, UK who has spent all his professional life in toxicology. He said that in “the last 46 years in studying sweeteners I have not seen any scientifically reproducible evidence that any sweeteners cause any harm to humans in the amounts normally consumed.”

He referred to the famous quote by Paracelsus (1493-1541) that “all things are poison … only the dose which makes something a poison”. There are variations on the translation, but simply put, it is the dose that determines whether something is good, neutral or bad for you.

He singled out aspartame, now approved in over 90 countries, stating that it has a larger safety database that any other food additive. Aspartame is a methylated dipeptide, comprising two amino acids phenylalanine and aspartic acid. You will remember from biology that amino acids make up proteins.

Some methanol is produced when aspartame is consumed, and you will hear people tell you scary stories about methanol, only because they don’t understand what Paracelsus said 500 years ago. Yes, methanol is produced but only in very small, non-harmful, amounts. There is more methanol in the same volumes of orange juice, apple juice and tomato juice than in a soft drink sweetened with aspartame. In fact there is six times more methanol in tomato juice than a diet drink, but you don’t hear scary stories about tomato juice, and neither should you because it is all about dose.

Nobody listens, no matter how many authoritative scientific reviews take place. Low-calorie sweeteners are among the most extensively studied of all food additives. Media stories about “health concerns” usually focus on a single recent observation and ignore the totality of the database available,” said Renwick.

Of course, because he says this, his words are quoted by agencies and companies that have a vested interest in sweeteners, so then people think that he has become a mouthpiece for sweeteners and can’t be trusted. That’s the way conspiracy theories work. One final comment he made was that the Wikipedia entry on the aspartame controversy was “surprising unbiased.”

I was asked about Natvia, which is a mix of Stevia and erythritol. Stevia has been discussed in an earlier blog. It is quite safe.

Erythritol is not often found in foods, although it comes from a common family of sugar-alcohols, a bit like mannitol and sorbitol often used for its sweetness, mainly back in the 1980s in confectionery such as gum and mints. Some of you will remember Blizzard mints with sorbitol. I always remember them because, when lecturing at a university I mentioned Blizzard mints as an example of a product with sugar-alcohols. After a few minutes one quizzical student put up her hand and asked: “Where do you buy “lizard mince”?” A reminder to me to enunciate better. Yes, it was funny, and no, I don’t think lizard mince is legal either.

Anyway, erythritol is a sweetener with about two-thirds the sweetness of sugar. It has passed all the safety and toxicology tests thrown at it, even at high doses. It is absorbed from the gut and excreted through the kidneys unchanged. Its sweetness works well in combination with stevia.

What does it all mean?
If you eat sensibly, then there is a very good chance that you will eat somewhere between none and very little intense added sweetener, in which case it shouldn’t alarm you. If you are consuming two litres of diet soft drink, a litre of diet cordial, 1 kg of diet yogurt and 10 cups of tea with two tablets of sweetener per cup then I’m willing bet that your overall diet is pretty crap anyway. My blunt and unattractive view is that people focus way too much on minor issues of no consequence, distracting them from doing something useful like giving to charity, walking the dog and reducing the amount of the most dangerous food additive known to man. It’s called salt, but who cares?

And yes, I do enjoy a diet soft drink after a long bike ride (60+ km for me), so don’t think that I can be trusted to give you a balanced argument on sweeteners!