Latest news on the acrylamide front from the Danish Cancer Society:
Acrylamide, if you recall, is a substance found in a vast array of common cooked foods, foremost starchy foods like potato chips, French fries and bread. Research some years ago found a “probable” association between acrylamide and cancer based on telling animal studies. Subsequent research has linked the substance with muscle and neurological degeneration as well as Alzheimer’s disease. Although much was made of the findings at the time, no action or significant warnings were undertaken in the U.S. In Europe, however, food safety experts have begun initiatives to reduce acrylamide nutritional intake. Similar studies in the last few years have shown varying results, inhibiting further action or scientific consensus on the issue.
The findings show a positive association between an increased acrylamide-haemoglobin level and the development of breast cancer after adjustment for smoking behaviour. The risk of breast cancer doubles with a tenfold increase in the acrylamide-haemoglobin level. A tenfold increase in the acrylamide-haemoglobin level corresponds more or less to the difference measured between the women with the lowest and highest exposure. The study also shows a stronger association for estrogen receptor positive breast cancer.
Animal tests have shown acrylamide to be a carcinogen, but until recently no studies have demonstrated a link between acrylamide in foods and cancer in humans. Ours is the first epidemiological study using biological markers for measuring acrylamide exposure, and the first to report a positive association between acrylamide and breast cancer,’ says Henrik Frandsen, senior scientist at the National Food Institute, Technical University of Denmark.
This is a powerful study with striking results. Let us first say that we know a few studies have come out in the last year and a half that contradict the food and acrylamide association, including one with 100,000 American women. The key difference here, as noted in the excerpt, is the assessment method used. While past studies for acrylamide have relied on subjects’ self report in food questionnaires, this research team was the very first to use “biological markers,” in this case blood acrylamide-hemoglobin levels.
This is the thing with medical research: the methodology is everything. If you’re basing your findings on the ability and motivation of people to remember everything they’ve eaten as well as their capacity to accurately judge how much of each thing they’ve eaten, you’re working with an inherently sloppy model. And it’s surprising how many nutrition studies are based on these methods. In an interview for Sunday’s edition of the New York Times, Michael Pollan, noted author of Omnivore and In Defense of Food talks about this premise of nutrition studies: “If you try to fill out a food frequency questionnaire, you realize very quickly this is not good data. I was as honest as I could be and tried to remember what I’d eaten, and it claimed I was only eating 1,200 calories a day. Clearly, I was forgetting at least 1,000 calories. We know people underreport by about 30 percent. We don’t know the first thing about nutrition, which is, ‘What are people actually eating?’ It’s hard to build good science on top of that.”
Now, if you round up your human subjects, like we do lab animals, and keep them captive for the duration of your research, controlling every action (or inaction), every morsel of food and molecule of air they breathe, then you might be getting closer to a reasonable level of reliability. For good reason, this approach is illegal. So, there you have the conundrum of human research – when it relies on self-report.
In this study, however, the biological marker tests allowed researchers to directly and accurately assess how much acrylamide the study subjects had consumed. Now this is a study worth its salt, and it’s not good news for carb addicts, in particular.
Nonetheless, the research team cautions that their study still doesn’t fully confirm the food-based acrylamide and cancer association. It’s possible that other compounds formed during cooking may be responsible. Additionally, the study cannot rule out acrylamide sources other than cooked food. So, the research will continue.
In the meantime, what should we take from this? Well, if you’re in the better safe than sorry camp, you might want to steer clear of cooked carbs (imagine hearing that on this blog!), and consider using alternative, lower temperature cooking methods.
The culprit, after all, seems to be the cooking process itself. Higher cooking temperatures are generally associated with higher levels of acrylamide. Most vegetables and high protein foods like chicken and beef show only moderate amounts of the substance, although experts suggest slow cooking at lower temperatures. Among cooked or baked starchy foods (which topped the list of acrylamide levels), scientists have found especially significant amounts of acrylamide in potatoes, when fried or cooked in either microwave or conventional ovens. Although the current EPA limit for acrylamide in drinking water is .12 micrograms per 8 ounces, the acrylamide load in a large order of Mickey D French fries weighs in at a whopping 82 micrograms, according to the Center for Science in Public Interest. In addition to bread and other baked goods, research shows relatively high amounts of the substance in coffee and dried fruits, especially prunes and pears.
So, maybe stick with fresh fruit. If you can’t bear to give up coffee (I understand), consider halving your intake and using green or black tea for an alternative caffeine boost.
As for the ongoing battle between raw foodies and grandmas, raw foodies, you seem to score a major point this time. But Grandma, you’re far from out of the game here. You were clearly onto something with all those slow cooked stews and crockpot meals. Give credit where credit’s due.
jetheriot Flickr Photo (CC)