22 BBC SCIENCE FOCUS MAGAZINE COLLECTIONDIETilled as the superheroes
of the culinary world,
today, superfoods are as
widespread as comic-book
movies – every day it feels
like a new one is being introduced.
“There is neither a regulatory nor scientific
definition of a ‘superfood’,” says Dr Jeffrey
Blumberg, from the Friedman School of Nutrition
Science and Policy at Tufts University, Boston.
“It is a marketing term that marketers do not
wish to define either.” But through an equally
unscientific survey of the books and blogs
that liberally use the term, some common
characteristics of these
so-called superfoods
can be discerned.
Superfoods typically
have high levels of
certain nutrients, such
as the goji berry, which
boasts more vitamin C
than oranges, more beta
carotene than carrots
and more iron than
spinach. Superfoods are
often exotic in origin –
the goji berry hails from
the Himalayas. “This
seems to suggest that
they have some special
health-promoting
properties,” says Dr Blumberg. “Although
the countries from which they come are
not characterised by especially healthful or
long-lived people.”
BE READY TO FORK OUT
Superfoods are often rediscovered and
repackaged staples of ancient civilisations,
which also lends them credibility and a
quasi-mythical air, even though those ancient
civilisations are long-dead. Like the goji berry,
which allegedly helped Chinese herbalist Li
Ching Yuen live to the ripe old (unverified)
age of 256. Coincidentally, he also sold goji
berries. Which leads us to perhaps their defining
characteristic: they’re expensive.The appetite for superfoods is growing –
according to the International Food Information
Council, nearly nine in 10 Americans are
interested in foods that have health benefits
beyond basic nutrition. But they’re also
swallowing some unsubstantiated claims.
Legends of doctors discovering remote
mountain tribes of age-defying, goji-munching
centenarians should self-evidently be taken
with a large pinch of pink Himalayan salt –
another superfood with little scientific backing
to elevate it above the table variety. But there’s
scarcely a grain of proof for the efficacy of the
goji berry or any other superfruit.
A Chinese study of 79
patients with advanced
cancers found that their
conditions regressed
when treated with goji
polysaccharides, as well
as immunotherapy. But
information about the
design of the study and
the compounds used is,
like evidence for the
majority of goji’s claims,
lacking. Another study,
on goji juice’s effects on
brain activity, was only
performed on 34 people,
and inconclusive at that.
Most of the various
studies related to goji and immunity, heart
disease and life expectancy have been either
sma l l or used concent rated ex t rac t s t hat wou ld
be unrealistic – not to mention costly – to eat
the equivalent of in real life.FREE RADICALS
Like many superfoods, such as blueberries
and açaí, goji berries are touted as being
high in dietary antioxidants. “They act to
quench reactive oxygen, nitrogen and halide
species, often called ‘free radicals’,” explains
Dr Blumberg, who is also the senior scientist at
Tu f t s’ A nt iox ida nt Resea rc h Lab. Free rad ica ls
are commonly cited as causing cancer – according
to the marketing, more antioxidants means lessThe goji berry
boasts more
vitamin C than
oranges, more
beta carotene
than carrots
and more iron
than spinach
B
RIGHT: Popular among
celebrities from Madonna
to Miranda Kerr, goji
berries have high levels
of certain nutrients
BELOW: Vegetables are
known to contain all sorts
of beneficial vitamins and
minerals. For example,
kale has been found to
lower the risk of cancer
and heart diseaseGETTY IMAGES