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  • superfoods

  • Hello, and welcome to Zoe shorts.

  • The bite-size podcast, where we discuss one topic around science and nutrition.

  • I'm Jonathan Wolf.

  • And as always, I'm joined by Dr Sarah Berry and today's subject is superfoods.

  • Yeah, that's right Jonathan from blueberries to salmon, to kale, it seems like anything

  • and everything can be classed as a super food these days.

  • Supposedly they can prevent everything.

  • Cancer reduce inflammation, help you live longer and make you look 20 years younger

  • as well.

  • Which you definitely don't need Sarah.

  • And I think the question today is, are some foods really more super than others?

  • Or is this just another clever marketing ploy?

  • I have quite clear on, so on this one.

  • Brilliant.

  • Maybe let's start with where the term superfoods, uh, originated.

  • And we did a little research on this.

  • The world's first so-called superfood was the humble banana.

  • In 1918, the Scientific Monthly published an article called The Banana, A Food Of Exceptional

  • Value.

  • Sure enough, food manufacturers got excited and the United Fruit Company ran with this,

  • putting out a massive marketing campaign around the time of world war one.

  • They said bananas are practical, cheap, and nutritious, and should be added to every meal.

  • Superfoods really took off in the 1990s where the us government endorsed blueberries has

  • been little antioxidant, rich disease fighters.

  • The department of agriculture retracted this research 20 years ago, but it didn't matter.

  • Blueberry production doubled and superfood mania took off.

  • These days it seems like there's a new superfood every week.

  • Garlic cinnamon, ginger green tea.

  • And so Sarah, what actually our superfoods.

  • So there is actually a dictionary definition for a superfood and the dictionary says it's

  • a food that's rich in compounds that are beneficial to health.

  • But there's actually no scientific definition of a superfood between the period of 2011

  • and 2015, there was about a 200% increase in the number of new foods and drink products

  • launched around the world that had the term superfood brand all over them.

  • And so what do they do?

  • Well, they're thought to contain all of these healthy nutrients and bioactives.

  • So antioxidants minerals, vitamins, as well as fiber and healthy sources of fat.

  • And so claims of superfoods and their supernatural ability have included everything from aiding

  • our digestion, preventing cancer, improving our brain function, reducing symptoms of autism

  • and so, so much more.

  • And one of the reasons why superfoods have been such a big deal is because it allows

  • them to talk about being really big in individual nutrients.

  • So the question is like, why are we so obsessed by this idea of single nutrients?

  • It turns out that this really comes from the history of nutrition and nutritional science.

  • Many of us probably remember at school, studying about scurvy happening to British sailors

  • who were stuck on a boat for too long, and suddenly realizing that they needed limes,

  • is why I understand I'm a limey, but actually it went much further than that.

  • And so a lot of nutritional science research in the 19th century was understanding a whole

  • series of different nutrients that we require, but this really became a big deal with governments

  • in world war one.

  • Different governments discovered that they had all of these soldiers that they couldn't

  • conscript.

  • Because of nutritional deficiency.

  • And so suddenly that really focused this idea that, you know, they might be getting enough

  • calories at this point, but they were really missing single nutrients.

  • And Sarah, I think that sort of continued through then into things like guidelines and

  • labels, hasn't it?

  • Yeah, absolutely.

  • So historically we've had nutrient based guidelines, but we don't eat nutrients.

  • We foods, we don't even eat single foods.

  • We consume dietary patterns.

  • And are we in a world still where most people, you know, in the west have to worry about

  • nutrient deficiency.

  • So nutrient deficiency is now really rare.

  • They're are a certain proportion of the population where iron deficiency anaemia is a problem.

  • But for the majority of people, nutritional deficiencies are just not a problem.

  • So we've come from this world of single nutrients.

  • Now we're talking about superfoods, like what do the research studies actually show?

  • So there's lots of research looking at single foods and single nutrients in relation to

  • cancer, heart disease and other conditions.

  • So for example, a recent review of cancer studies found that people who include mushrooms

  • in their daily diet had lower risk of cancer.

  • And this was thought to be because mushrooms contain ergo thianine, which is an antioxidant

  • rich chemical to protect cells, there's been research into nuts showing that people that

  • consume more nuts have 50% lower risk of cancer research in tomatoes because they contain

  • cancer-fighting lycopene.

  • All of these studies though, are either using supplements or using mega doses of these amounts

  • of plants.

  • So how they translate in real life is questionable.

  • I can see that the American Institute for cancer research says that the evidence is

  • too limited to draw any real conclusions.

  • Uh, cancer research UK says there is no good evidence that any one food prevents cancer,

  • including superfoods, it's true that a healthy, balanced diet can help to reduce the risk

  • of cancer, but is unlikely that any single food will make much of a difference on it's

  • own.

  • Yeah, and foods work in unison and how one nutrient and one food impacts, another nutrient

  • is really important.

  • So that's again, why we have to be cautious making interpretations from some of these

  • either supplement studies or megadose food studies in relation to their health qualities.

  • And I think the other thing we have to do is really look at the details of the research,

  • right?

  • So in general, there's a big claim out of a particular paper.

  • It gets blown up in the media and it's not necessarily backed up really by the evidence.

  • So if you look at many of these studies, right, they're on very small numbers of people.

  • They're done for a few months.

  • Some of them are not even done on human beings.

  • There are one or two examples.

  • Aren't there, Sarah of single food studies that actually go on for many years and enough

  • time to actually see whether it has any impact on these health outcomes.

  • There are only a couple of these kind of studies because they're so challenging, uh, to run,

  • for example, a study called the cosmos trial that was looking at how polyphenols impact

  • a whole host of outcomes using a supplement.

  • But generally they all suffer from the limitations that you've just listed.

  • So we're left saying, you know, can there be a superfood?

  • What's the bottom line from where we are today, Sarah?

  • So in my opinion, there is no superfood that there is a super diet, and this is a diet

  • that's diverse.

  • That's packed full of fruits, vegetables, legumes of a plant-based and also a highly

  • unprocessed diet as well.

  • Now I think we can say that there are some foods that have super healthy effects on us,

  • but I still wouldn't class them as superfoods.

  • And by these, I mean, berries, fish, leafy greens, nuts, olive oil, live yoghurt and

  • legumes.

  • And if we can get a decent amount of those into our diet, then I think we're onto a super

  • healthful diet.

  • And is that because the big challenge with the idea of superfood is it suggests that

  • you can keep your current diets and just add this superfood sort of like a drug, right.

  • We were used to this idea that you can get some sort of magic drug that solves your infection

  • or whatever it is.

  • And it's that way you're you're so against the idea of a superfood.

  • Yeah.

  • I think it's a really reductionist approach.

  • Just so like the reductionist approach that you mentioned earlier with us focusing on,

  • on single nutrients.

  • And I think it's because it's our whole dietary pattern that actually determines the healthiness

  • of our diet rather than a single food.

  • Often we have to consume huge amounts of these so-called superfoods to reap the health benefits.

  • And we also have to consider the food that it's displacing and replacing.

  • So by adding a large amount of one particular food into our diet, what are we actually displacing

  • for our diet?

  • Are we still getting a balanced amount of other nutrients and other foods?

  • And, and when he's still having that most important component of our diet, which is

  • diversity.

  • And what about olive oil?

  • If there's anything that could be a superfood, surely it's olive oil.

  • There's a real long-term randomized control trial, right?

  • With PREDIMED CORDIOPREV of over seven years, there was genuine impact on heart disease.

  • Doesn't that get to be a superfood, Sarah?

  • So olive oil is one of those that I just listed as being a super healthy food, but it's more

  • that terminology that we can focus on a single food to elicit good health in us.

  • So this is like you can't eat McDonald's and then have olive oil and somehow be healthy.

  • And this is what's standing in the way of it getting the, uh, the Sarah Berry super

  • food.

  • Absolutely.

  • That's brilliant.

  • What about I thought about this also.

  • I think there's one other potential sort of superfood, cause I think one of the biggest

  • challenges is, you know, how do you take all of that advice into real life, particularly

  • if you have a family.

  • And so, you know, I definitely see this, you know, with my kids in particular, trying to

  • get them to eat a healthier diet.

  • And so my other thought about a superfood is, well, sometimes our superfood is something

  • where you can do a swap.

  • You've made it significantly healthier for your family.

  • And actually they're very happy to have that, you know, quinoa is a good example of something

  • which was described as a superfood.

  • I know you hate the idea of it as the superfood, but we know that if you're swapping out, you

  • know, rice, for example, for quinoa like you've significantly improved.

  • The property is because of it's whole grain.

  • It's got more protein, less refined starch, or indeed.

  • I've managed to get the whole family to swap out regular pasta for whole wheat pasta and

  • they're completely happy.

  • So are we allowed to think of those as a sort of minor superfood or, or am I pushing too

  • far?

  • I think we can think of them as a super swap.

  • And I think that super swaps is a great dietary strategy to modify your diet and make it healthier

  • because.