Everyone eats food. This is one of the upsides of communicating science as a nutrition researcher: it will always be relevant, and everyone can see why it matters to them.
But it’s also one of the worst things, because it means that everyone has an opinion and feels empowered as an expert on food.
I often find myself debating with people who have strong opinions on nutrition that aren’t really backed up by the science. What starts as good nutrition research is so easily twisted by marketing hype into overblown health claims.
Goji, acai, coconut water, kale and quinoa are some examples you’d be familiar with. There’s also things like shilajit resin, which is basically overpriced Himalayan compost. More recently, it’s cockroach milk that’s being touted as the superfood of the future. Just as an aside, it really does come from cockroaches, but it’s not technically milk.
Superfoods are marketed as miracle foods that can apparently make you live longer, and cure and prevent all kinds of diseases.
But the science doesn’t really support the hype. I’m not saying that there’s no scientific research into superfoods, but we definitely don’t call them super.
Is acai a superfood?
For example, let’s look at a study that showed that eating acai pulp increased the level of antioxidants in the blood. Antioxidants neutralise free-radicals — molecules that can damage our cells.
Taken in isolation, maybe this does look like evidence for acai as a “superfood”, but it’s not nearly that simple.
To start with, the study cohort was super small: only 11 people. And although they did show a rise in antioxidant levels after eating the acai, they got the exact same spike after the participants ate the control food, which was apple sauce, and I’m pretty sure no one is calling applesauce a superfood.
Also, the dose was very high. A participant who weighed 70 kilos would have had to eat about 500ml of the acai and apple sauce. When did you last sit down to eat half a kilo of berries or six apples all in one go?
Finally, showing a spike in antioxidants in the blood does not necessarily prove a health benefit. When it comes to antioxidants, and vitamins in general, more is not always better, especially if you aren’t deficient in the first place.
In fact, in very high concentrations and when reacting with certain chemicals, antioxidants can actually act as pro-oxidants, which have the complete opposite effect! You’re probably better off just avoiding sources of free radicals to start with, like drinking and smoking.
The downside of superfoods
I’m not saying these studies are “bad science”. It makes sense to study the way popular foods change our body chemistry, and all studies have limitations.
But you can’t take a bunch of studies like this that test high concentrations of foods, on small cohorts, over short durations of time, in ways that aren’t reflective of regular eating habits and arrive at the claim that superfoods can stave off illness and old age — especially not when a standard fruit like an apple, which costs a fraction of the price, can give you the same result.
It’s easy to see why the superfoods idea is so popular; it’s a cure-all in tasty food form. But rather than making us healthier, the superfood concept might actually be doing us harm.
Superfoods foster the idea that we can somehow compensate for our other bad habits. You could convince yourself that cocktails aren’t so bad if they have acai in them, or that giant muffin you had this morning is a health food because of all the blueberries.
Cost is also an issue. Super berries cost 10 times that of your average every day berries, but they certainly don’t have 10 times the nutritional value.
If you like them and want to splash the big bucks, go ahead, but be aware that this price bump helps perpetuate the myth that it’s more expensive to eat a healthy diet.
What most of our diets are lacking is variety. No single superfood, or even a collection of the top superfoods, will save you from an overall bad diet.
Too much of anything isn’t good
Just as there’s not one thing that will save us, there’s also not one single thing that’s killing us. Often, when people find out what I do for a living, they want to know which is worse: fat or sugar? I can see why they ask, every week there’s a new fad diet or media piece declaring that it’s one or the other that’s “really” killing us.
But you don’t have to quit things to be healthy, and likewise you aren’t automatically healthy just because you’ve quit something. Sure, too much of anything isn’t good for you, that’s precisely why we call it “too much”.
It doesn’t have to be all or nothing. In fact, some sugar, and some fat are vital for good health. You need fat to build new cells, absorb fat soluble vitamins, make hormones, and both sugars and fats are important sources of energy. In fact, glucose, a sugar, is literally the only source of molecular energy that can run our brain cells.
Exclusionary diets promote anxiety and orthorexia, an obsession with healthy eating. And people are also often misled about the health benefits of the much more expensive substitutes they’re eating. For example, in the absence of an allergy or an intolerance, there is no health benefit associated with going gluten free, but it will cost you more.
Most “sugar free” recipes call for ditching cane sugar and switching to alternatives, like agave, or malt rice syrup. These are still sugars, they’re only marginally more nutritious, but they cost dramatically more than cane sugar, again, perpetuating the myth that it’s more expensive to eat a healthy diet.
Bad science can make big money
From a public health perspective, we’re better off teaching a good relationship with food that promotes moderation and variety based on the dietary guidelines, rather than promoting fear and loathing.
By the way, just because you know someone who lost weight on an exclusionary diet that does not mean it’s healthy. Slim people can be poorly nourished, and overweight people can be metabolically healthy. Weight is only one marker of health, and rapid weight loss can actually be an indicator of poor health.
I got into nutrition science because I wanted to understand how our bodies work, and ultimately improve health outcomes in the future. But nutrition is also a multi-billion-dollar industry and the good science sometimes gets obscured by even better marketing.
Sometimes I think about the money that can be made, and I wish I had a few less scruples. But then I think of the harm that nutrition myths can do, and I’m very happy forgoing fortune for science.
Dr Emma Beckett is a postdoctoral fellow in the School of Medicine and Public Health, University of Newcastle. This is an edited extract of her talk for Ockham’s Razor.