The truth about ‘miracle foods’ – from chia seeds to coconut oil
As books that give answers go, there’s one
classic that often gets overlooked – the
dictionary. So next time you’re wondering
whether a £10 tub of the latest miracle
food can really stave off cancer, diabetes
and heart disease, and get rid of a podgy
belly in time for summer, run your finger
down to the word “miracle” where you will
find this definition: “an extraordinary and
wondrous event” – so far so good – “that
cannot be explained by natural or
scientific laws”.
“Whether it’s coconut oil, chia seeds or
apple cider vinegar,” says Duane Mellor,
an assistant professor in dietetics at the
University of Nottingham and a
spokesperson for the British Dietetic
Association, “there is no scientific evidence
to suggest that if you top up your diet with
any ‘miracle’ or special food that you’ll get
any of the promised effects. The idea is
almost entirely a marketing vehicle, but
when people read claims online, they start
to think differently and can start believing
it.” One of the reasons people might
believe the hype is because as with any
good miracle – or magic trick – the success
lies in smoke and mirrors. With miracle
foods, while the magical health food
salesman is conjuring a few extra coins out
of our pockets, we’re left bamboozled by
scientific terminology.
“Many products tend to be accompanied by
all sorts of horrendous scientific jargon,
like ‘maintains cognitive function’,” says
Mellor, “which are watery, scientific-style
claims that people tend to read as being
something meaningful to human health.
Then there’s antioxidants and free
radicals, which are some of the most feared
and misunderstood words used.”
Free radicals are unstable elements that
come spinning off any oxygen-using
chemical reaction in the body. They are
unstable because they are missing an
electron and, in a bid to restabilise
themselves, they steal an electron from
elsewhere. This could be from the fats in
cell membranes or from your DNA. The
damage they do when bullying other
elements into handing over an electron is
called oxidative stress, and this can be
associated with heart disease, cancer and
diabetes.Free radicals, however, are also involved
in beneficial processes. They help to
destroy invading bacteria and play a part
in cell communication. To limit their role
to only those things that benefit us, our
bodies make things called antioxidants
that, much like people standing outside
nightclubs handing out hugs and hot
chocolate to pacify drunken revellers,
provide free radicals with the electrons
they need so they don’t cause damage
elsewhere.
“But if you look at the antioxidants
circulating in our bodies,” says Mellor, “by
far the most common are the ones we make
ourselves – glutathione and uric acid –
followed by vitamins A, C and E, which we
get from normal food anyway. Many of the
antioxidants in things like chia seeds are
there to stop the plant oils going rancid, or
to protect them from sunlight damage, and
may not be that available to our bodies
anyway. So although the EFSA [European
Food Safety Authority] allows
manufacturers to claim that their products
are rich in antioxidants – because they are
– manufacturers are not allowed to claim
any health benefits. If you look carefully,
it’s sort of legalese what they end up
claiming.”
Even when used as supplements,
antioxidants don’t seem to provide any
benefit. A large study published in the
New England Journal of Medicine that
followed nearly 10,000 people over an
average of four-and-a-half years showed no
benefit from vitamin E supplements in the
prevention of heart disease. Studies for
other antioxidant supplements have been
equally discouraging.
Part of this confusion is because diet is
complex. It’s tough to tease apart the
contribution of individual components
because the nutrients in many foods
become available to us only when eaten as
part of a wider diet: studies have shown
that only when we cook carrots can their
beta-carotene become more available and;
the lycopene in tomatoes is most readily
available when they are eaten with oil.
But what about all the other vague claims
about foods that can help you lose weight,
or support a healthy immune function, or
lead to a healthy heart? They all sound
good and sort of make sense, don’t they?
According to Ali Khavandi, a cardiologist
at the Royal United Hospital in Bath, these
claims are vague for a reason – they are
based on experiments carried out on
animals or on human cells in a lab. They
have not been shown to have any effect on
people, and until such effectiveness is
shown, he says, we should stay open-
minded but cautious about exaggerated
claims.
“As doctors I think we’ve taken our eyes of
the prize,” he says of the importance of a
healthy diet in avoiding the major chronic
diseases such as heart disease and
diabetes. “For the past few years, at least
for heart doctors, I think we’ve been more
interested in the sexier side of preventing
disease – new drugs, stents, and operation
techniques – and we’ve left the diet arena
a little unmanned. It’s now been populated
by unqualified people and celebrity health
gurus spreading misinformation. As
doctors I think we have an obligation to
reassert an authoritative voice when it
comes to healthy eating.”
Yanking the spotlight back from celebrities
and fad food products might be a difficult
task. “The problem,” says Khavandi, “is
that the message we try to get across –
which is based on proper, robust evidence
that has been shown time and time again –
is not very interesting to people. They have
heard it all before.”
The messages he is talking about include
the fact that fruit and vegetables are good
for you. As are wholegrain cereals and
nuts. For fats, which you need, choose
unsaturated fats such as olive oil and those
directly taken from marine sources such as
oily fish. Neutral foods, he says, are
saturated fats like butter or coconut oil and
unprocessed red meats – eat these in
moderation and they’re unlikely to do any
harm. Stay away from excess white-flour
products, processed meats, and trans fats
such as vegetable oils and palm oils found
in fast foods.
Simple enough advice on the face of it, but
with sensationalised articles emerging
daily about the benefits or dangers of
specific foods, people get confused and
lose sight of the simple messages. A
complication nowhere more true than with
cancer.
“There is certainly no such thing as an
anti-cancer diet,” says Justin Stebbing, a
consultant oncologist and professor of
cancer medicine and oncology at Imperial
College London. “But I have patients
asking me things about these foods all the
time.” He puts a finger on why cancer-
busting food is such an appealing concept.
“As a patient, disease makes you lose
control. People immediately want to regain
that control and a very easy way for them
to do that is by diet, and they can get all
sorts of things off the internet. We should
understand that the internet is a double-
edged sword and if we’re looking for
information we should go to reputable
sites.”
Such sites, says Stebbing, are NHS Choices,
Cancer Research UK, Diabetes UK and the
British Heart Foundation, which all give
clear, evidence-based dietary
recommendations. Duane Mellor has
another simple rule of thumb for
distinguishing cherrypicked claims from
bona fide scientific evidence. “The EFSA is
very clear – and very strict – about what
health messages it allows companies to use
in the marketing,” he says.
“If you see a claim on a blog, and if it’s
persuasive and looks good, ask yourself
why has the company not used it in their
marketing? If the product really did
prevent cancer or heart disease, do you not
think it’d be plastered all over the
packaging?”
Mythbuster: the facts about
five ‘miracle foods’
1. Coconut oil
The claim: Coconut oil is a saturated fat.
While not the heart-clogging evil they
were once thought to be, it would take a
leap of faith to proclaim that they are good
for you. A recent review of studies
suggested that saturated fats raise levels of
both good and bad cholesterol. The oil is
predominantly a medium-chain
triglyceride that, proponents state, might
carry benefits for weight loss, but this
claim has not been shown in human
studies. Other suggestions for the benefits
of coconut oil include helping blood
glucose regulation and preventing strokes
and Alzheimer’s – again, none of these
benefits have been shown in people.
Dietetics professor Duane Mellor’s
verdict: Probably best to enjoy a little
coconut oil in a Thai dish occasionally
rather than using it daily!
2. Apple Cider Vinegar
The claim: Doubtless a tasty condiment,
but has been anecdotally linked with an
eye-wateringly long list of potential health
benefits in areas including: digestive
disorders, sore throats, high cholesterol,
indigestion, preventing cancer, dandruff,
acne, energy boosting, cramps, and helping
with blood sugar control. The EFSA,
however, hasn’t approved any of these
claims. Many of the studies have been on
animals or in laboratories using human
cells.
Mellor’s verdict: Vinegar is probably best
kept as a condiment. Use it on salads
instead of high calorie oils and
mayonnaise and to add flavour to sauces to
help reduce salt intake – it might help, not
because of anything it contains, but
because it would be replacing less-healthy
foods.
3. Manuka Honey
The claim: A medical-grade version of this
honey is used in sterile wrappings. As with
most honeys it has hydrogen peroxide,
which gives it its antibiotic qualities. It
also has methylglyoxal, an antibacterial
component, in much higher quantities
than found in other honeys. Studies have
suggested that manuka honey might help
to ease symptoms of infections such as
coughs, but it’s not clear whether the
honey is having an antimicrobial effect or
whether it is just soothing like all syrups.
Mellor’s verdict: Any of the claims for
eating manuka honey, all of which have
been rejected by regulators, are vague. Any
health benefits must be balanced against
the very high quantities of sugar compared
with the very small amounts of these
proposed active compounds.
4. Spirulina
The claim: This is another proposed
miracle food for which regulatory agencies,
this time the US National Institutes for
Health, say there is not enough scientific
evidence to support any health claims.
Rejected claims include those relating to
metabolic and heart disorders (eg blood
pressure control and diabetes), and also
mental health disorders such as anxiety,
depression and ADHD. It does have useful
nutrients – calcium, niacin, potassium,
magnesium, B vitamins, iron, and essential
amino acids – but the jury is out on
whether your body can use these nutrients
in plant form.
Mellor’s verdict: Spirulina shouldn’t be
relied on as a source of nutrients. Rather
than taking such supplements, it would be
better to spend your money on vegetables
and fruit – this will help to make your
whole diet better rather than adding a
supplement and not thinking about the
food you actually eat.
5. Chia seeds
The claim: Packed with antioxidants, but
many of these are of plant origin so less
likely to be available to us. They have high
omega-3 content, too, but our bodies are
not great at using omega-3 oils from plants
– it’s best to get these oils from oily fish
such as salmon. But for people who don’t
eat fish, chia and other seeds can be a good
substitute. Other potential pluses are
linked to their high protein and fibre
content, which have led some to suggest
they might help you lose weight by
reducing hunger. However, two trials to
date have shown no evidence of any
benefit in terms of weight loss or reduced
risk of heart disease.
Mellor’s verdict: Chia seeds can add an
interesting texture to bread. Linseed and
hemp seed are also rich in omega-3 fatty
acids, so chia is not unique and should be
enjoyed more for its effect on texture
rather than any particular health effects
