Introducing Evidence-based Keto: Your no-hype guide to the ketogenic diet
We've spent the past year analyzing the research on the keto diet, and have just released Evidence-based Keto.
Clocking in at over 200 pages with 500+ references, it's the unbiased guide you need to the ketogenic diet.
Last week was abuzz with headlines ranging from …
● “Nutella causes cancer!” to …
● “Don’t worry, Nutella doesn’t actually cause cancer!”
Which one is correct?
Neither. Here’s what the research actually said. If you’re in a rush, read the blue boxes or the end of the post. If you’re curious, read the whole thing. It’s super interesting, we swear!
A report came out in May of 2016 from a European food safety agency. Under review were some potentially carcinogenic compounds found notably in refined palm oil. And Nutella contains refined palm oil.
So why did all the buzz happen seven months after that report? Because the Italian maker of Nutella, Ferrero (which invented the chocolate-hazelnut spread in the 1940s and currently uses about a quarter of the world’s hazelnut supply), decided to start fighting back this month, responding to outcry and proposed regulations in Europe. And the media took note.
Anyway, back to the report. It focused on three specific compounds:
● GE (Glycidol Ester) is the compound that gets most of the press. The GE content of palm oil is much higher than that of other oils.
● 3-MCPD and 2-MCPD can both be produced alongside GE, and can be harmful on their own.
The report found that GE is bad news, at least in animal studies. As a “genotoxin”, it can damage DNA, which is a causative step in the formation of cancer cells. 3-MCPD harmed the kidneys and male reproductive organs of the experimental animals. Data on 2-MCPD were scarce, so we won’t talk more about it.
A report from May of 2016 was revisited by the media in January of 2017, after the makers of Nutella launched an ad campaign defending its use of palm oil — a campaign spurred by Nutella being pulled off the shelves of some Italian supermarkets, and by potential regulations in Europe. The report looked at three potentially harmful compounds in palm oil, with the media especially focusing on GE (Glycidol Ester).
It turns out that babies are at the greatest risk of consuming too much GE, because some babies rely on infant formulas as their sole food source. And guess what can be quite high in GE? Yup, infant formulas. This is yet another reason why breastmilk is pretty great, though in some cases formulas are the only option to feed a baby.
The below chart, copied from the European agency’s report, shows two important points:
● Babies and children tend to consume much more GE (and 3-MCPD) than adults.
● Babies who drink formulas have it the worst off, with more than twice the average intake.
Hold on a sec! This whole Nutella scare may actually apply more to babies (particularly those fed formulas) than to adults. That’s because adults eat a variety of foods, whereas babies don’t. Older children aren’t off the hook, since they often eat a lot of snacks that can contain GE, and also eat a lot in proportion to their bodyweight in order to grow.
People absolutely love shrugging off cancer reports. Either that, or letting the report scare the heck out of them. We like to take the middle ground, as in the case of last year’s big red meat and cancer report. So … how important is it for you to cut down on Nutella?
The full paper is massive (159 pages) and contains one little line that isn’t mentioned in the abstract:
The report looked at animal studies, mostly in rats and mice. None of the studies were in humans. This severely limits the conclusions that can be drawn from the data, for two reasons:
● We aren’t exactly like rodents. For example, they can make their own vitamin C out of glucose; we can’t, so we have to eat it. More to the point, cancer studies in rodents often don’t translate to humans, partly because rodents seem to be more susceptible to cancer.
● When you lack human data, you end up with really rough risk estimates. For GE, the report’s authors took the dose that caused cancer in rats and divided it by 25,000, then used that number as the “safe” level in humans. Without human data, though, it’s hard to know if this really, really large (and somewhat arbitrary) number isn’t overly cautious.
Finally, one should remember that, in real life, people don’t consume steady supplies of isolated compounds. Nutella is composed of several ingredients, and we eat it in combination with other foods, in different and varying amounts over time.
We lack human data on those compounds, so nobody knows how dangerous they really are. Given the discrepancies that can occur between rodents and humans with regard to cancer, the report might not apply all that well to us. That doesn’t mean you should eat refined palm oil or Nutella all day every day; it just means that the report was really just an initial step in the research.
The report was not a study of Nutella, and that’s what scaremongers don’t seem to understand. GE is formed at processing temperatures above 200ºC (nearly 400ºF). Nutella is processed at much lower temperatures specifically so as to reduce the production of contaminants like GE.
Plus the report explicitly states that between 2010 and 2015, GE levels in palm oils and other fats went down by half due to changes in manufacturing.
Nutella is produced at fairly low temperatures that minimize the production of GE. The report is of greater concern for people who eat refined palm oil that isn’t known to be produced at safe temperatures.
That doesn’t mean you should ignore the report, though. At the very least, you should ask yourself this question: Why was refined palm oil targeted? The answer: Because it is rich in a type of fat called DAG (diglyceride), whereas other oils have more of the normal stuff, triglyceride. And as far as the research group could tell, refined oils are the only direct source of GE in the human diet.
Smelly oils, like palm oil, often need higher heats to deodorize them, otherwise people wouldn’t use them as cooking oils and in food products. And while vegetable oils are somewhat low in DAG when fresh (around 1–3%), once stored and transported they can have double that amount even before refining.
Purified DAG oil was actually studied for genotoxicity back in 2005, with no link being found. Which may seem confusing, since purified DAG oil has around 80% DAG and palm oil around 10% — but genotoxicity tests can differ, as can refining processes. Anyway, purified DAG cooking oil was a big hit in Japan, under the name of Enova, and there’s been a decent amount of research into purified DAG potentially helping with weight loss and metabolic syndrome.
But wait, why don’t you see Enova on supermarket shelves anymore? Because it was voluntarily discontinued in 2009 due to potential toxicity concerns! In other words, it was a canary in a coal mine.
The high DAG content of palm oil is part of what makes it potentially harmful. People don’t use purified DAG oil anymore, but high-DAG oils could be a concern. If you don’t eat refined oils, nor foods that contain them, you don’t have to worry about this report.
DAG can’t produce GE without reacting with chlorine. In fact, 3-MCPD fits under the category of CHLOROpropanol, so chlorine is crucial to this story. Therefore, to be safe:
● Don’t cook your oils in chlorinated pool water (joke).
● Be careful when heating Splenda/sucralose (not a joke).
Splenda, a.k.a. sucralose, is a polychlorinated artificial sweetener. So it’s got chlorine in spades. While Splenda is safe according to current evidence, not much of that evidence is on heated Splenda. It turns out that heating Splenda could generate substantial amounts of the potentially harmful compounds we talked about above.
Other ways chlorine might figure in the equation aren’t that well researched. For instance, it’s possible that fertilizers containing chloride could make the problem worse, but there’s been very little research.
Heating Splenda (e.g. baking with Splenda) may generate chloropropanols. Researchers don’t know much about this, but keep it in mind if you’re a Splenda junkie.
Although palm oil has an especially high GE content, other oils can be a concern, too. Moreover, most people eat foods containing refined oils (e.g. potato chips and baked goods) more often than they eat isolated refined oils (e.g. sunflower oil), so those foods are the greater practical concern. The charts below (copied from the report) show GE levels per kilogram of foods and isolated oils.
Although palm oil has been singled out, other refined oils, whether in isolation (e.g. sunflower oil) or in foods (e.g. potato chips and baked goods), can also be a concern.You probably just want to know the answer to this question: Should I worry? Luckily, the answer is similar to our takeaways from other reports.
If you eat a diet of mostly unprocessed plants and animals, you’re fine. Carcinogens are everywhere; it’s the dose that makes the poison. But if you eat foods containing refined oils on a daily basis, especially high amounts of refined palm oil, you may want to lower your intake.
High-heat processing is not very healthy, especially for oils; it can produce a variety of potentially toxic substances, from the ones mentioned in this report to other scary initialisms like PAHs (polycyclic aromatic hydrocarbons). Again, of course, it’s the dose that makes the poison, so the occasional junk food or fried food isn’t a deal breaker.
Humans may eat unhealthy foods and live unhealthy lifestyles, but we’re not lab rats. The report covered only animals studies, which often don’t apply all that well to humans. We don’t know if humans detoxify these compounds differently from rats. We do know that, in our bodies, some of these compounds are conjugated to glutathione in order to neutralize them, and that glutathione is one of our bodies’ powerhouse antioxidants — the production of which is also supported by a healthy diet. So eat your greens!Like this article? There’s a reason we’re one of the most trusted sources in nutrition and supplement research. If you’re tired of sensationalist headlines and want to get to the facts, sign up for our free supplement course in the box below.
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