By now you’ve probably read one of the countless news stories proclaiming that Nutella causes cancer. And if you’re like me you’ve reluctantly resigned yourself to your fate at the hands of such hazelnutty goodness. I dug a bit deeper to learn about the science behind the viral headline and what it means for our favorite toast spread.
Did a team of scientists sit down to besmirch our beloved Nutella? Not quite, no. In fact, Nutella was not mentioned once in the studies conducted.
The European Food Safety Authority (EFSA) regularly publishes an annual overview of food safety science conducted over the course of the year. In 2016, one such study looked at the presence of three known carcinogenic (cancer-causing) compounds in vegetable oils and processed foods: glycidyl fatty acid esters (GE), 3-monochloropropanediol (3-MCPD), 2-monochloropropanediol (2-MCPD).
Vegetable oils. Ah-ha! Now we’re getting somewhere. One of the primary ingredients in Nutella is palm oil. Did you know that palm oil smells? It’s quite pungent in fact. It doesn’t ruin the flavor of your food because food processors remove the odor before production. The deodorizing process involves heating the oil to significant temperatures (above 200°C). During that process, the contaminants form.
Herein lies the problem. Glycidol, the parent compound of GE, is both carcinogenic and genotoxic (capable of damaging DNA) and as such there are no safe limits of consumption. In animal studies, 3-MCPD caused kidney and reproductive damage in males. Palm oil contains both contaminants in significant quantities.
The EFSA report presents that “palm oil and fat contain the highest levels of both contaminants: both average and high GE and 3-MCPD levels are some six and four times higher, respectively, than the amounts in the next highest category (normal fat margarine). Low fat margarine contains approximately three times less GE and 3-MCPD than normal fat margarine.”
So what’s the risk? As with most things in life, the answer is complex. Dosage matters. Yes, 3-MCPD is carcinogenic and yes animal studies have shown other rather unfortunate side effects. The World Health Organization (WHO), based on toxicology studies in animals, sets the LOEL (lowest observed effect level) at 1.1 milligrams/kilogram body weight/day before cancer of the kidney was noted. In other words, chronic consumption would need to exceed 1.1 mg/kg bw/day for danger. According to the same EFSA study, the average European adult was exposed to 0.4 mcg/kg bw/day of 3-MCPD, which is equivalent to .0004 mg/kg bw/day.
WHO provides a tolerable daily intake (TDI) level of 2 mcg/kg bw/day. Much lower than the LOEL, but generally recognized as the number you would do best to remain below.
Does Nutella cause cancer? That’s an overly simplistic question. As currently formulated with palm oil, the data suggest that Nutella increases your risk of cancer if and only if the palm oil is heated to the temperature required to produce the contaminants.
You would need to eat an unrealistically large amount of Nutella to put yourself at any immediate risk assuming Nutella has not taken the requisite steps to prevent contaminant occurrence. Will consuming palm oil based food stuffs increase your risk of cancer over the long term relative to similar products that use other vegetable oils? The data suggest that it will.
And that is the key takeaway. Risk is assessed on a dietary-wide scale meaning that singling out an item of food is generally unhelpful in assessing overall risk. Instead, understanding total uptake of specific ingredients better suits an informed discussion of risk. Then again, people are far more likely to read a story about Nutella than about one of its ingredients, palm oil.