Page 24 - BBC - The Scientific Guide to a Healthier You
P. 24
DIET
5“Plus, our body’s own antioxidant systems expectations of what they will do. “I prefer
– involving compounds like glutathione – are the concept of ‘high nutrient density’ foods,
more powerful than what we can get from food.” which is a central theme in the new 2015-2020
dietary guidelines for Americans,” says Prof
TRICKY TO STUDY Nieman. “The term ‘superfood’ is not used
The proof of the superfood pudding is in the by most scientists because the implication is
eating… by humans, not mice or rats. But that one can expect quick and high-end health
unfortunately, most scientific research is not benefits.” By all means, sprinkle some chia seeds
conducted this way. “Nutrition studies often on your oatmeal. You’ll get a nutritional boost,
don’t apply to real life on a 1:1 basis,” says but you won’t instantly become an Olympian
Patel. “If you want to test, say, the effect of athlete. “What matters is the habitual eating
grape juice on cognition, you’d give it enough pattern over years,” says Prof Nieman.
time, plus you’d check to make sure they
actually drink it. In real life, that almost never The problem is not that
happens.” Lifestyle factors are difficult if not
impossible to separate. And there are other
problems, says Patel – pilot studies and animal superfoods are a con – many
trials will often use larger dosages, while ‘acute’
studies will look at just the food without any are highly nutritious – but
other things consumed. Meanwhile, eating
different foods together, which is what most calling them ‘super’ gives
of us do, can dramatically alter their effects us unrealistic expectations
for better or worse.
Another issue affecting superfood research
is that it is often paid for by interested
parties. “We’re funded by food and supplement A BALANCED DIET
companies in many of the studies we conduct,” By seeing superfoods as a magic bullet, we risk
admits Prof David Nieman, director of the shooting ourselves in the foot.
Human Performance Labs at Appalachian State “Some people think if they eat one ‘superfruit’,
University in North Carolina. “But the system they don’t need to eat the other recommended
demands contractual agreement that gives four servings of fruit a day,” says Dr Blumberg.
the primary investigator ‘academic freedom’, But no one superfood is a panacea – nor
The blueberry is often
or the right to publish the data, positive or referred to as the will it make up for other deficiencies. “Adding
‘grandaddy’ of the
negative. Many of the companies I work with superfoods to a good diet is fine,” says
superfood movement
are so convinced that their product has special Dr David Katz, director of Yale University’s
effects that they sign these agreements.” Prevention Research Center. “Counting on them
What buyers should beware of are to compensate for a bad diet is not.”
studies conducted in-house by Undue emphasis on superfoods can be
companies, which are “close to unhealthy. “The term helps companies
worthless”, says Prof Nieman. But sell product, and it ‘helps’ consumers
while industry-funded doesn’t mean oversimplify their diets,” says Patel.
false, the anointed superfood might All the experts cited here stressed
not be much better than a cheaper the importance of consuming a wide
equivalent that doesn’t have the variety of natural, ‘whole’ foods, which in
same commercial imperative (see turn reduces their individual significance.
‘Everyday heroes’, page 26). “No single food or beverage is important
The problem is not so much that enough to stand out from the overall lifestyle,”
superfoods are a con – many of them, such as points out Prof Nieman.
chia seeds or kale, are highly nutritious – more Another unintended consequence of the GETTY IMAGES
that calling them ‘super’ gives us unrealistic fashionable superfood label can be felt in 5
24 BBC SCIENCE FOCUS MAGAZINE COLLECTION
