Acrylamide

[arcticpenguin]

http://sciencenow.sciencemag.org/cgi/content/full/2003/130/2

Study finds no link between acrylamide consumption and cancer

Interesting result. This is one of those studies where they ask a bunch of people what they eat and then estimate their acrylamide consumption, so the methodology is not all that impressive.

I have been wondering; humans have been cooking foods for tens of thousands of years, shouldn't we be selected for acrylamide resisitance by now?

[aerocontrols]

Originally posted by arcticpenguin

I have been wondering; humans have been cooking foods for tens of thousands of years, shouldn't we be selected for acrylamide resisitance by now?

I doubt it, since most cancers occur after the age of fertility. Add to that the fact that over the majority of those tens of thousands of years, humans had a very low average life span, any sort of resistance to acrylamide probably didn't change ones chance of being 'naturally selected'.

MattJ

[Goshawk]

Eh, AP, your link won't let me read it without registration. It's the "fries won't give you cancer after all" story?

http://news.bbc.co.uk/2/hi/health/2702241.stm
High levels of a chemical found in foods such as chips, crisps and bread do not, as feared, seem to raise the risk of cancer, research suggests.

Research in the past year has shown that many types of cooked food contained moderately high levels of a chemical called acrylamide, which is considered to be potentially carcinogenic. So, once again the Scientific Community does an Emily Latella "...never mind..." :rolleyes:

April, 2002 (http://news.bbc.co.uk/2/hi/health/1949413.stm), "French fries cause cancer!" :eek:

August, 2002 (http://news.bbc.co.uk/2/hi/programmes/4x4_reports/2183386.stm), "And microwaving, too! So you can't have even microwave fries!" :eek:

And now it's "... :D never mind..." ?

I'm going to stop listening from now on. Next time I hear some health pundit say, "New research has shown...", I'm going to cover my ears and go, "La la la la la la I can't hear you..."

[gmol]

Originally posted by arcticpenguin
http://sciencenow.sciencemag.org/cgi/content/full/2003/130/2

Study finds no link between acrylamide consumption and cancer

Interesting result. This is one of those studies where they ask a bunch of people what they eat and then estimate their acrylamide consumption, so the methodology is not all that impressive.

I have been wondering; humans have been cooking foods for tens of thousands of years, shouldn't we be selected for acrylamide resisitance by now?

(JTBP: just to be pedantic):
I believe that shoud be "poly" acrylimide; the acrylimide monomer is a potent (I think neuro) toxin; the polymer is not obviously harmful.

I don't follow your reasoning. Why in the world would you expect us to have evovlved acrylimide resistance? I don't think that humans were ever subjected to selective pressure on acrylimide resistance....I always thought polyacrylimide was a modern polymer...(i.e. not used for thousands of years)...?

We were however subjected to selective pressure from bacterial, viral infection and sharp pointy things, things that go "bang",fire and cyanide...

We didn't evolve resitance to all of those things just because they were around.

[Goshawk]

The difference between acrylamide and polyacrylamide.
http://www.fsai.ie/rapid_alerts/alerts/an_2002_cancer_chemicals.htm
http://www.techno-preneur.net/timeis/andhra/invopp/Mineral/pAPacrylamide.htm
Acrylamide is an active vinyl monomer with two functional groups. It is marketed in solid form and also as aqueous solution.

Acrylamide is almost entirely utilised in the manufacture of different grades of polyacrylamide for use in a number of industries, particularly as floculants in liquid solid separation. The deal with acrylamide was that carbohydrates like potatoes and cereals, when heated, produce naturally-occuring acrylamide, which is technically classed as a "possible" human carcinogen. I don't think people would have needed to evolve resistance to a carcinogen, because cancer tends to be a slow-moving degenerative disease of middle and old age, by which time you've already reproduced. People have evolved resistance to things like measles because those are diseases that strike fast and weed out the weaker members right away. Those individuals that have resistance to a fast-moving disease, and survive it, will reproduce, but with cancer, it's not necessary.

[arcticpenguin]

Originally posted by gmol


(JTBP: just to be pedantic):
I believe that shoud be "poly" acrylimide; the acrylimide monomer is a potent (I think neuro) toxin; the polymer is not obviously harmful.

I don't follow your reasoning. Why in the world would you expect us to have evovlved acrylimide resistance? I don't think that humans were ever subjected to selective pressure on acrylimide resistance....I always thought polyacrylimide was a modern polymer...(i.e. not used for thousands of years)...?

We were however subjected to selective pressure from bacterial, viral infection and sharp pointy things, things that go "bang",fire and cyanide...

We didn't evolve resitance to all of those things just because they were around.
If you're going to be pedantic it pays to be correct. Work on that. http://news.bbc.co.uk/1/hi/health/1993435.stm

Yes, the new one is the "fries won't give you cancer" story.

[gmol]

Originally posted by arcticpenguin

If you're going to be pedantic it pays to be correct. Work on that. http://news.bbc.co.uk/1/hi/health/1993435.stm

Yes, the new one is the "fries won't give you cancer" story.

Re -reading, I did misinterpet your original post...
It wasn't clear to me that they were talking about acrylimides formed in the food as opposed to acrylimides leeched from the polyacrylimide in food packaging (used to package things like cereal, chips etc.)...thanks for clearing that up Goshawk.

That being said, I still don't see why you would expect humans to nessecarily evolve resistance to a carcinogen? Would that not imply that there would be people today who are not genetically pre-disposed to certain types of cancer? People have been exposed to cancer for generations and we haven't evolved resitance to it either!

[Jon_in_london]

It amazes me that everyone is still ignoring the fact that acrylamide is a POTENT CUMULATIVE NEUROTOXIN
:rolleyes:

[gmol]

I thought begining to think that my professor was just scaring me when we made up those polyacrylamide gels...

[Jon_in_london]

I thought begining to think that my professor was just scaring me when we made up those polyacrylamide gels...

No! honestly! We had this one lecturer who lost all feeling in his finger tips from not using gloves when handling acrylamide (I think it affected his brain too, but thats just my opinion, he was a bit er... eccentric).

[spoonhandler]

Hi all.

Reading through my copy of the MSDS on acrylamide suggests that it is a potent neurotoxin even at very low levels and that its carcinogenic effects are more related to its ability to cause germ cell mutations (inheritable disorders in offspring) rather than any links with spontaneous tumours in adults. The exposure standards apparently allow for those toxic effects that are symptomatic (central nervous system injury) but reproductive health damage occurs at much lower levels (at least that's how I interpret the information).

Whenever we use the stuff, we treat it with respect - lots of controls to prevent exposure.

I think if people are looking for a reason to be concerned about acrylamide in fried food, it might be related to all the talk about increasing rates of infertility, birth defects and so on.

It's interesting to ask the question whether a germ cell mutagen can be 'out-evolved' so to speak. We'd have to consider whether some offspring have better evolved or more efficient repair mechanisms than others and so on. Of course, we already have very sophisticated means of detecting and disposing of mutated cells that pose a threat to the status quo. Only when these mechanisms are either overwhelmed by whatever is causing the damage or undermined by faulty genes in the first place do they fail.

I think...

:)

[Goshawk]

But...nobody's saying that acrylamide isn't poisonous, that it's not a neurotoxin. That's not in question. The point of the original "medical alert" was that acrylamide was suddenly discovered to occur in certain cooked foods, and that technically acrylamide might (repeat, might) be a human carcinogen. "Carcinogen" is different from "neurotoxin". Obviously there isn't enough acrylamide in French fries to make people keel over sick or dead when they eat them, because somebody would have noticed. The Powers That Be were just concerned about cancer developing in people who ate French fries every day for 20 years.

And so the point of the followup medical alert is that there's now officially no link discovered between eating cooked foods that may have acrylamide in them, and cancer.

If somebody's going to start worrying about a connection between acrylamide in fried foods and birth defects or infertility, they'll have to get a new grant from somewhere and do a new study. This study was just about cancer.

[Jon_in_london]

Gos,

My point is that while everyone was in a flap about some tenuous 'probable carcinogen' thingy they were ignoring the fact that it is a potent cumulative neurotoxin- ie. repeated small doses have a cumulative effect. Anyway........

About the germ line mutagenesis: could this be a factor in the flagging fertitlity rates in the western world?

[Mr. Turquoise]

With regard to the health risks that fried foods pose, after high blood pressure, heart disease, diabetes and obesity, if you are still looking for a reason to cut down, then a POSSIBLE cancer risk isn't likely to be a big motivator. I mean, has anyone really changed thier diet because of a news story?

The lesson to be learned here is that the media jumps on board anything that it can sensationalize, and otherwise rational people decide to start doing irrational things like wearing aluminum foil on their heads.:mad:

Just my opinion.

Mr. Turquoise

BTW, thanks for the heads up on this story arcticpenguin; it flew right under my radar.

[spoonhandler]

I agree with Mr Turquoise - living has been shown to be associated with an increased risk of death and the media love to remind us of all the different ways we can die. :)

I realise what the recent reports into acrylamide in food have been about Goshawk - I was interested in arcticpenguin's original question about whether organisms can develop a resistance to something like this and Jon-in-London's point that surely we'd all be suffering CNS damage before cancer was an issue.

As a germ cell mutagen, acrylamide could potentially cause birth defects or impact on fertility rates. I should also have pointed out that acrylamide may cause mutations in the genome of otherwise apparently healthy offspring that later on contribute to the development of adult cancers (loss of heterozygosity, activating mutations, etc, etc), either in them or their own offspring. It could be that acrylamide is contributing to cancer rates worldwide.

Which gets back to arcticpenguin's question - can we evolve resistance to this phenomenon? If so, it would be based on an organism's ability to detect and eliminate mutations.

We evolved a sophisticated mechanism of detection and repair or removal of cells damaged by UV which allows us to live in sunlight, but too much exposure overwhelms this system, leading to cancer. Alternatively, offspring with damaged repair systems, faults in the genes that are involved in preventing UV damage from getting out of hand, result in someone almost guaranteed to get skin cancer even if they never experienced sunburn, tanning, etc. If the repair system is really faulty, they may get cancers at such a young age they do not get the chance to pass their genes on.

Acrylamide in very, very low doses could introduce defects into the germline without leading to clinical neural damage that is not otherwise considered part of the aging process. Maybe the issue of acrylamide in food should be given consideration along these lines.

The day I heard peanut butter gives you cancer was the day I stopped worrying about what we had to eat to avoid death from something unpleasant. Now I just try be moderate and stay happy.

[Soapy Sam]

gmol- we may well have evolved resistance to certain cancers. Those would be the ones nobody dies of anymore and which don't get studied for that very reason. (Medecine evolves too!)

Also the "resistance" we have evolved may have taken precisely the form of only allowing the oncogene to be expressed late in life. Possibly once upon a time, some cancers which now occur in later life were common in young individuals. The ones who developed it later had more time to reproduce their late developing gene.

Evolution is sneakily complicated.

[gmol]

Of course we have, but my point is that there are many we have not. The mere existance or constant exposure of something harmful does not imply the development of resistance. It may be that if you cook up enough potatoes in your average lifetime, you get cancer from acrylimide. People may have been doing this for thousands of years; that (and the fact that we are alive right now) does not imply that we would evolve resistance to it. There may be no genetically tractable mechanism of resistance to some things, selection is always being carried out in the context of competing pressures etc.

I remeber being taught in school(!) that girls will eventually lose their hymen and we will all eventually lose our appendicies. This IMHO, represents a fundmental mis-understanding of evolution (assuming of course that those tissues are functionless). The original statement echoed the same kind of vibe...

Originally posted by Soapy Sam
gmol- we may well have evolved resistance to certain cancers. Those would be the ones nobody dies of anymore and which don't get studied for that very reason. (Medecine evolves too!)

Also the "resistance" we have evolved may have taken precisely the form of only allowing the oncogene to be expressed late in life. Possibly once upon a time, some cancers which now occur in later life were common in young individuals. The ones who developed it later had more time to reproduce their late developing gene.

Evolution is sneakily complicated.