Tuesday, 7 March 2017

The Science of 

Superfoods

Kale and chia, goji berries and blueberries, salmon and spinach. JAMIE MILLAR investigates the science behind whether superfoods are the magic bullet that can cure all our ills, and which ones deserve their ‘super’ prefix


Tricky to study

  The proof of the superfood pudding is in the eating – by humans, not mice or rats. But unfortunately, most scientific research is not conducted this way. “Nutrition studies often don’t apply to real life on a 1:1 basis,” “If you want to test, say, the effect of grape juice on cognition, you’d give it enough time, plus you’d check to make sure they actually drink it. In real life, that almost never happens.” Lifestyle factors are difficult if not impossible to separate. And there are other problems, pilot studies and animal trials will often use larger dosages, while ‘acute’ studies will look at just the food without any other things consumed. Meanwhile, eating different foods together, which is what most of us do, can dramatically alter their effects for better or worse: “Co-consumption makes things more complicated.” 
  Another issue affecting superfood research is that it is often paid for by interested parties. “We’re funded by food and supplement companies in many of the studies we conduct,” admits Professor David Nieman,Director of the Human Performance Labs at Appalachian State Universityin North Carolina. “But the North Carolina university system demands contractual agreement that gives the primary investigator ‘academic
freedom’, or the right to publish the data, positive or negative. Many of the companies I work with are so convinced that their product has special effects that they sign these agreements.” What buyers should beware of are studies conducted in-house by companies, which are “close to worthless”, says Prof. Nieman. But while industry-funded doesn’t mean false, the anointed superfood might not be much better than a cheaper, less exotic equivalent that doesn’t have the same commercial imperative. The problem is not so much that superfoods are a con – many of them, like chia seeds (right) or kale,are highly nutritious – more that calling them ‘super’ gives unrealistic expectations of what they will do. “I prefer the concept of ‘high nutrient density’ foods, which is a central theme in the new 2015-2020 dietary guidelines for Americans,” says Prof. Nieman. “The term ‘superfood’ is not used by most scientists in the field, because the implication is that one can expect quick and high-end health benefits.” By all means, sprinkle some chia seeds on your oatmeal, and even stir in some blueberries. You’ll get a nutritional boost, you just won’t instantly become immortal: “What matters is the habitual eating pattern over months and years.”

The goji berry boosts more vitamin C than oranges, more beta carotene than carrots and more iron than spinach



Many of superfoods are highly nutritious, but calling them ‘super’ gives unrealistic expectations

A balanced diet
  By seeing superfoods as a magic bullet, we risk shooting ourselves in the foot. “Some people think if they eat one ‘superfruit’, they don’t need to eat the recommended 2-4 servings of fruit a day,” says Dr. Blumberg. But no one superfood is a panacea; nor will it make up for other deficiencies. “Adding superfoods to a good diet is fine,” says Dr. David Katz, Director of Yale University’s Prevention Research Center in the US. “Counting on them to compensate for a bad diet is not.” And undue emphasis on superfoods can be unhealthy. “The term helps companies sell product, and it ‘helps’ consumers oversimplify their diets,”. All the experts cited here stressed the importance of consuming a wide variety of natural, ‘whole’ foods, which in turn reduces their individual significance. “No single food or beverage is important enough to stand out from the overall lifestyle,” says Prof. Nieman


Inflated health benefits

The chia seed is a good example of how claims about superfoods can grow out of all proportion

  A variety of mint, over recent years chia has broken out of those novelty pet-shaped pot plants to become an Aztec warrior miracle food. It’s a complete protein with all the amino acids required to build muscle, plus more omega-3 than salmon, more fibre than flaxseed, and wealthier than Montezuma himself in antioxidants and minerals. Indeed, cheerleaders of chia allege you could eat it and nothing else. “It’s a good example of how companies and distributors promote the mystique and magical health benefits that go way beyond the science,” says Professor David Nieman, Director of the Human Performance Labs at Appalachian State University in North Carolina. “We conducted several randomised human trials showing that chia seeds provide good nutrition and can be included in a healthy eating pattern that over time – along with physical activity and weight management – is consistent with good health. But there’s nothing quick or miraculous about them.”



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