Heated Starches and Cancer Risk

Discussion and Comment

When this story was released, it created something of a stir, as you can imagine. Carbohydrates, particularly the starches, which are called 'complex carbohydrates' or 'polysaccharides', are what are supposed to be 'healthy'. But these cannot be digested without first being cooked. And, if the Swedish report is true, it is the heating of starches that causes the problem. So we have the situation where you can't eat tham without cooking, and cooking may make them likely to cause cancer.

Since the Swedish report was published, there has been some discussion about the scientists' evidence and the implications of their findings. I have been a member of that discussion. In the following discussion I have not published names but they are all at least doctors of medicine; some are professors.

Discussion

Two scientists suggest that this report is 'junk science'. One told me:

"Another food-scare. The hallmarks of junkscience are there.

"To present them: The claim is based exclusively on high dose studies in laboratory animals (genetically modified rats or mice prone to cancer). There is no evidence whatsoever that humans eating the foods in the press release are exposed to any risk of any cancer.

"The solemn calculations of a number of cancer cases per year caused by the food — all, of course, taken completely out of the blue. (serious business this, very.)

"This is done by using the myth of the no-threshold. Forgetting that everything is toxic — or not-toxic — it's all a matter of the dose.

"(Cancer researchers call the presentation highly misleading.)

"Forgetting that we every day are stuffing ourselves with natural plant-derived (fruit and vegetables) cancerogenous substances and still have managed to survive and prosper the last 500,000 years. (Hey, what a liver we have)

"The researchers chose, instead of using the normal procedure for scientific work — the peer reviewed publication — to (frantically) go public in a press conference. Nice to get in the papers!!

"They are already applying for grants ( a few millions at least) from EU to carry on the important work, which they'll probably get. (before any publication. Sic!) And a good income is worth its weight in gold these days.

"Everything taken in consideration, you probably can't even use it as an argument for or against the prudent diet. Sorry, that's how bad it is."

Another doctor agreed with this.
However, this was countered from a third with:

"I beg to differ. The number of cancer cases can never be ascertained, but when WHO has set a limit of 1 microgram/d, is then 2000+ micrograms per kilo in many nutrient deficient "foods" insignificant? Compared with paleolithic times, the level of carcinogens in the environment must have increased thousands of times — why is it that another insult could not be a significant factor in carcinogenesis?"

This found agreement from doctor four:

"You are absolutely correct. To assume there is no threshold in estimating the risk of cancer is junk science. The dose is what counts.

"Also ignored is the fact that at doses below the threshold there are usually hormetic (beneficial) effects. Evidence from many animal studies show that animals dosed at levels below the threshold level (no effect level) are often healthier than the control (zero dose) animals.

"By the way, have you read Alice Ottoboni's book, The Dose Makes the Poison , John Wiley and Sons, Publisher?

Doctor five told me:

This new research (told by our food experts at Livsmedelsverket) says that acryl amid — normally seen as a carcinogen and a neurotoxic compound — is (seems to be) created in many kinds of food, mainly with fried or heavily heated starch. There are still too many questions to be answered. E.g. how amid is created and which is the nitrogen source, proteins etc?

The risk estimations (by Livsmedelsverket) say that up to 700 cases/year of cancer can be caused by acryl amid in Swedish food. This is an extremely high risk level if this is true. The general accepted/tolerated risk level of a single carcinogen in our society is usually 1 case among 1.000.000 persons during a lifetime. In our case the estimated level is up to 5000 higher than that?

By the way polyacryl amid (with some acryl amid as a monomer) is used in the food industry as a flocculant, e.g. sugar production. And the sewage sludge is heavily loaded with these two compounds.

We will inform you about the continuation of this Swedish drama. As I said, many questions need to be answered and the doubt is there.

So who is right? And, what are we to make of this? I agree with an American expert in nutrition who wrote to me:

"But we have ample evidence that it is the sugars in carbohydrates that cause the metabolic imbalances that lead to many diseases, so we do not need to invoke any other reason that carbohydrates are the source of dietary-related illness."

Conclusion

There is no doubt that although fats are blamed for most diseases today, there is much compelling evidence that carbohydrates are the real culprits. Whether this latest research from Sweden is confirmed or not, the fact that simple carbohydrates (sugars) and non-starch polysaccharides (fibre) have both been shown to be harmful in terms of increased cancer risk; and all carbohydrates, including starches, have been shown to increase the risk of obesity, diabetes and heart disease, is already sufficient reason to eat foods such as bread, pasta and starchy vegetables with care.

Last updated 27 April 2002

Last updated 27 April 2002