Wednesday, 13 February 2008


So lots of stuff about sweeteners in the news so I'm going to talk about them some more...

The study everyone's talking about is one that fed 1 group rats a liquid sweetened with normal sugar and the other group with a liquid sweetened with saccharin.
After 10 days of exposure, the rats were allowed to eat a high-calories chocolate-flavoured snack. The saccharin group ate more and gained significantly more weight than the sugar group.

They also found that rats that were accustomed to eating the sweetener didn't have a temperature change after eating- normally, body temperature should rise after eating.
They suspect that that could mean that the rats' appetite control mechanism was disrupted as a result of consuming sweetener, possibly leading to them overeating.

Their theories/interpretations of their results, in a nutshell, are:

1. Artificial sweeteners may disrupt the body's natural ability to 'count' calories based on the food's sweetness. Early in life, our bodies learn that sweet foods and dense foods have more calories. It's
a Pavlovian type of behaviour. Sweeteners impair this natural relationship. The body may be fooled into thinking a product sweetened with sugar has no calories. As a result, people become unable to regulate their food intake... and therefore, their weight.

2. Liquids, diet or not, are not as satisfying as solid food.

Challengers of this study (like the Calorie Control Council that represents companies that sell artificial sweeteners!), say the research oversimplifies the complex issues that contribute to obesity in humans and lots of studies have shown that artificial sweeteners can help with weight loss.
The researchers point out that the increase consumption of artificial sweeteners is not the sole cause of obesity, but it can be a contributing factor.

Other challengers say that the study was done on rats, not humans. True. However, other studies done on humans have shown a link between artificial sweeteners and weight (see previous blog). The researchers do point out that the results need to be replicated on humans. They also want to look at whether age and gender are contributing factors...
I would like to point out though that in 1958, in the US, Congress passed the Delaney amendment to the food and drug laws which required the FDA to ban any substance from the food supply shown to cause cancer- in people or animals and even rats.

Challengers also point out that saccharin is banned in Canada. True. However, researchers say that the results would apply to other artificial sweeteners .
Supposedly, Canadian officials are reviewing the restriction on saccharin in light of new research showing it may not be harmful to humans... not sure about that one though. In 1977, saccharin was banned in the US because it was shown to cause bladder cancers in mice and rats. However, the Calorie Control Council launched a huge publicity 'freedom of choice' campaign and, Congress allowed saccharin back on the market. Interestingly, it cost 6% less to sweeten cola with saccharin versus sugar at that time... hmmm.

These are the sweeteners that Health Canada has approved for use and some comments:

1. Aspartame (Equal, NutraSweet, Sugar Twin, Sweet n' Low, also added to foods). According to Health Canada, safe for use in pregnancy. Acceptable Daily Intake (ADI): 40mg/kg body weight per day. One can diet pop= 200mg. So, a 110lbs person can safely have 2000mg a day= 10 cans Diet Coke/day. Flavour may change when heated.

2. Acesulfame-K (Added in packaged foods and beverages). Safe in pregnancy. ADI= 15mg/kg body weight/day. One can diet pop sweetened with acesulfame-K=42mg. A 110lbs person can safely have 750mg per day = 18 cans Diet Coke/day.

3. Cyclamate (Sugar Twin, Sweet n'Low, Sucaryl). Avoid when pregnant.
ADI= 11mg/kg body weight/day. One packet Sugar Twin=264mg. A 110lbs person can safely have 550mg per day = 2 packets/day.

4. Saccharin (not allowed to be added to foods and beverages but available in tablets as Hermesetas). Avoid when pregnant. ADI= 5 mg/kg body weight per day. One tablet Hermesetas has 12 mg saccharin.

5. Sucralose (Splenda, also added to foods and beverages). Can be used for baking or cooking. Safe in pregnancy. ADI= 9mg/kg body weight per day. One packet of Splenda contains 12mg and 1 cup Splenda has ~250mg. A 110lbs person can safely have 450mg sucralose per day.
Interestingly, Whole Foods Market refuse to sell products containing sucralose since it's not metabolized in the body and could be potentially unsafe. The products goes against the company's philosophy of selling "the highest quality natural and organic products available".

Bottom line: A healthy diet should not rely on soft drinks- diet or not- or sweeteners.


Jme said...

Well if the rats on sweetener learned that sweet foods are NOT high in calories then it should be fairly easy to extend the study and see if having access to sweet and high calorie snacks reverses this in any way. Like if there is a balance somewhere between the immediate affects and what their behaviour would be if they had access to the high calorie snacks more often.

Sybil Hebert, RD said...

Hi Jme,
I'm sorry but I don't think I understand your comment.
Are you saying that if you now feed the heavier rats that were used to artificial sweetener regular sugar, they would lose weight?

Jme said...

hey Sybil,
i was saying that it seems like the rats had a bad reaction to the high calorie snacks because they were refused sugar for the 10 days. Now that they are being fed both the sweetener and the high calorie snacks maybe their body will adjust and recognize that sugary foods are high in calories? though not as much as the rats that are being fed sugar water and high calorie snacks.

Sybil Hebert, RD said...

I see, yes... maybe you're right about that.... Humans would most likely not eliminate all sugar from their diet and consume only artificial sweetened stuff and then re-introduce sugar.... So, in that sense, the experiment doesn't mimic real.
As I mentioned, other studies done on humans have shown that those that ate more artificial sweetener tended to be heavier than those that didn't. The rat experiement introduces another theory as to why that is...
Evidently, more research has to be done though.