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Unfortunately, this improved understanding of the biochemistry of addiction has yet to be translated into improvements in
treatment. The latest figures from Britain’s National Treatment Agency suggest that only 11 % of those who start treatment complete
it and are drug-free after 12 weeks.
A new approach that acknowledges the underlying biochemistry might improve this situation. And on October 11
th
and 12
th
delegates to a conference in London, organised by Food for the Brain, an educational foundation, heard accounts of such an approach.
Its tools are not drugs but dietary changes. The theory is that providing food rich in the precursors of lost neurotransmitters will boost
the levels of those chemicals, and thus reduce craving. At the moment, only preliminary trials have been carried out. But they look
promising and if larger trials confirm them, a useful, new front in the war on addiction might open up.
Mind what you eat
Anxiety and sleeplessness are common withdrawal symptoms. They happen because many addictive drugs reduce the supply of
a chemical called glutamine, a precursor to GABA. One of GABA’s roles is to promote relaxation. (The molecular receptors for
GABA are the target of tranquillisers such as Valium.) But glutamine levels can be restored, and production of GABA boosted, by the
consumption of an amino acid called N-acetylcysteine (NAC) that is found in nuts and seeds.
This is not just theory. A controlled study published last year in the
American Journal of Psychiatry
by Steven LaRowe, of the
Medical University of South Carolina, and his colleagues, found that giving NAC to cocaine addicts reduced their desire to use the
drug sufficiently for it to be recommended as a treatment. A different study found that NAC reduced the desire to gamble in more
than 80 % of those addicted to this pastime, compared with 28 % of those who were given a placebo.
Serotonin is another neurotransmitter that is usually deficient in an addicted brain. This probably accounts for the depressive side
of withdrawal symptoms (serotonin receptors in the brain are the target of antidepressant drugs such as Prozac). Serotonin is made
from an amino acid called tryptophan, which is found in foods such as meat, brown rice, nuts, fish and milk. Philip Cowen, a
psychiatrist at Oxford University, has found that reducing the amount of tryptophan in someone’s diet increases depressive symptoms
and also that increasing it can induce a more optimistic outlook.
Another molecule that shows promise in treating addiction is DHA, a fatty acid belonging to the nutritionally fashionable class
called omega-3.
In this case it is believed to act not by affecting neurotransmitter levels but by changing the physical characteristics of nerve
cells’ outer membranes, and thus the way they conduct nerve impulses.
A lack of DHA has been associated with all sorts of psychological problems – learning difficulties, excessive hostility and even
suicide. It has also been associated with the relapse into addiction.
Here, though, the waters are muddy. Correlation is not causation, and no decent trials have yet been done to show whether DHA
supplements do in fact reduce addiction. Indeed, the whole area is, as it were, under-trialled. As David Smith, another Oxford-based
researcher and the chairman of the conference, pointed out, drug companies are not interested in carrying out such trials because the
results, even if favourable, are unlikely to be patentable.
Governments do not seem interested at the moment, either; the welfare of addicts, rhetoric aside, is rarely a priority. Similar
studies of the effect of diet on the behaviour of prisoners are, though, provoking interest. John Stein, yet another Oxford man, is
currently conducting such a study in three British prisons. If a change of diet really can help addicts, it would be a shame not to find
out. It might even save the public purse some money.
T a s k O n e. Make up questions covering the subject matter of the article.
T a s k T w o. Write a review on the article.
A R T I C L E 3. Eating their words.
Oct. 23
rd
2008
From
The Economist
print edition
On food safety, the Chinese press applies an odd precautionary principle
IT IS, declares China’s foreign ministry, a "big step forward" in its handling of foreign journalists in the country. On October
17th a temporary relaxation of rules governing their activities, introduced for the Beijing Olympics in August, was made permanent.
The Chinese press, however, has no such good news.
Until the Olympic reporting rules came into force in January last year, foreign journalists based in China needed government
approval for any reporting trip outside their city of residence. Officials often insisted on tagging along. Many journalists would travel
without permission, but local police often stopped them, seized their notebooks and expelled them from their areas.
The new freedoms have their limits. Permits are still needed to report in Tibet. And even since January 2007 the Foreign
Correspondents’ Club of China has logged 336 cases of official interference in foreign journalists’ work. But their travails are trivial
compared with those endured by Chinese journalists, who, unlike them, have to cope with a barrage of directives issued by the
Communist Party’s Propaganda Department.
This helps explain why the Chinese media were slow to reveal the dangers of contaminated milk powder sold in China (and to a
far lesser extent, exported) in the months leading up to the Olympics. The powder made tens of thousands of children ill and killed at
least four. Chinese journalists knew about the problem, if not the full extent of it, weeks before it became public in September. But
officials and dairy executives, apparently worried about spoiling the mood at the games (not to mention their reputations), did not
want news to spread.
Journalists had to be mindful of long-standing, but mostly secret, orders from the Propaganda Department about reporting food-
safety issues.
The Economist
has seen a directive issued by a provincial propaganda bureau. Circulated in January 2005, it bans the
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