Sorry to harp back to Gary Taubes’ Diet Delusion again. I make no
pretence at having read the book, just Taubes’ own ‘teaser’ in New Scientist
last week. Rather than be ‘teased’ by the ‘comment & analysis’ piece, I have
been left somewhat annoyed.
To accuse the nutrition profession of creating ‘a field of clinical medicine
that functions more like a religion than a science’ is to shoot down all the
hard work that nutritionists around the world have been doing to wrestle the
science of nutrition out of the exclusive hands of the medical field, while
trying to persuade those medics to adopt a greater understanding of nutrition
and incorporate this into their pharmacologically dominated practice.
As this article was winging its way to my desk last week, I was enjoying a
very interesting discussion with Dr Barrie Margetts, who runs Southampton
University’s Masters course in Public Health Nutrition. This is the field that
brings the latest fundamental science from the laboratory to the populous and
feeds back the results of the interventions that have been tried. Or at least
that’s the theory. Margetts and his colleagues in public health nutrition are
not practising a straightforward science. There was a time and a place, briefly,
when experimental human nutrition was approached in much the same way we study
animal nutrition today. But we don’t like to talk about that nowadays.
The problem is people.
People make the recommendations. People try to make a difference. People are
on the receiving end of the interventions. People aren’t bacteria, or chickens.
You can’t feed people two diets differing in one component only and expect them
to stick at it for the three months it might take to see a biological
difference. Give us five pieces of fruit for free every day and however much
information you give us with it, we might still grab a pizza on the way home. Or
swap the fruit for something else. And then pretend we didn’t.
Public health nutritionists are well aware of this situation. Some of them
are also trying to do something about it. As Margetts pointed out, aid
programmes as well meaning as the Gates foundation’s work on micronutrients
in Africa, or interventions as well publicised as Jamie Oliver’s school
dinners campaign in the UK have no value to the science of nutrition, nor to
the future of public health nutrition, because they are not designed to assess
the outcome of the intervention. Obviously, it doesn’t help the cause of
philanthropy to report back that giving schoolchildren one free piece of fruit
every day only increases those children’s’ consumption of fruit by one third of
a portion a day as a UK government-funded scheme found in 2006. But in science,
even negative results are more cost-effective than none at all.
Public health nutritionists the world over are uniting to develop a useful
framework under which to work, but the world of nutrition is far too complex a
place for Taubes to sit on the outside throwing pieces of rotten fruit at it.