Monday, 14 July 2014

Acrylamide: A shady side of yumminess

'Homemade freedom fries'
by sean dreilinger under
a CC license
EFSA has recently published a draft scientific opinion indicating concerns regarding acrylamide intake and its potential role as carcinogen.

If that is as alarming as it sounds, why don't we take action now to eliminate it from our food?

And, at any rate, what can we do about it?

The brief answer to the latter is that acrylamide is not easy to get rid off entirely, as is forms during common food processing, both at the kitchen level and the industrial level. But, yes, we can reduce it further by modifying the cooking and processing steps. "Brown it lightly, don't burn it" is the simple rule to follow!

The answer to the former, however, is a bit more difficult to give using hard data to back it up, because total acrylamide intake is normally rather low and there is not too much evidence on the effect of acrylamide consumption on consumers, yet. So right now, reasonable caution is the most prudent thing one can advise.

OK. If you are still with me and can bear with me for a little longer, here is the slightly more detailed version of the story...

Acrylamide is a chemical compound formed in starchy foods when they are heated at high temperatures, starting at low rates from about 120 oC,  for prolonged time. It is just one of the many products of the so-called Maillard reaction, which actually is a large set of reactions, that take place when amino acids (the building blocks of proteins) and reducing sugars are heated together. The Maillard reaction products contribute considerably to the brown colour and the characteristic taste and flavour of baked, grilled, fried, etc. products.

Most of the food-contained acrylamide comes from the consumption of potato crisps, fried potatoes and coffee. Other starch-containing food that have been subjected to high temperatures, such as rusks, bread, etc., also contain acrylamide but typically in lower (or much lower) concentrations. EFSA's draft opinion quotes a mean intake that ranges from 0.3 to 1.9 μg/kg body weight. Indicatively, smoking also adds to the acrylamide intake by 0.5 to 2  μg/kg body weight. Once consumed, acrylamide is metabolised either to N-acetyl-S- (3-amino-3-oxopropyl) cysteine or Glycidamide. It is mainly the latter metabolic product that raises the concerns for acrylamide's genotoxic and cancerogenic properties.

So how big is the risk?

EFSA follows the Margin of Exposure (MOE) approach. MOE is the ratio between the dose where no adverse effect is observed to the estimated human exposure. To estimate the risk level, MOE is compared with the product of the uncertainty factors that need to be taken into consideration. Those are factors applied to data obtained from animal studies and account for the various differences between species (taking into consideration safety factors, as well). In the current case of examining acrylamide's genotoxic and cancerogenic properties, EFSA calculated a MOE much higher lower than the product of the uncertainty factors, thus indicating concern.

Acrylamide production during food processing is not a new story. In fact, there are indications that acrylamide content has been reduced lately as awareness for acrylamide concerns increases.

Currently there is little evidence through human studies on any alleged effects of acrylamide. Evidence comes mostly from animal studies, where acrylamide's consumption effects have been observed. Such toxicological studies often study consumption regimes unrealistically higher than normal human intake, within non-typical diets. The latter implies that the ingestion of acrylamide is not accompanied by ingestion of other ingredients that may - in vivo - play a role in its actual effect. Despite those uncertainties, that doesn't mean that acrylamide concerns should be dismissed. Rather that caution should be advised and studying of the issue should continue.

In Europe, sampling and analyses for acrylamide content in food has been ongoing for several years now. Parallel to that, the food industry has been using an acrylamide "toolbox" in an effort to reduce acrylamide content in processed food. At the industry level, there is also the possibility to use different raw materials (less prone to acrylamide formation), enzymes (to break down or modify the protein content that contributes to acrylamide formation), etc. All those are steps towards the right direction and take place in parallel to the efforts to fully characterise the risk.

Acrylamide, as mentioned previously, also forms during cooking food at home. There, the rule of thumb is "Lightly brown it - Don't burn it!". Which goes together with the common sense advice to maintain a balanced diet with variety in the foods consumed.
Note: Various organisations across Europe have produced relevant FAQs or info-sheets. If you are in Europe, it's worth checking at your national Food Authority's website. E.g., BfR (DE), ANSES (FR), EFET (GR), FSAI (IE), FSA (UK), AECOSAN (ES), etc.

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