杏吧原创

IT鈥橲 a chance discovery so unexpected it defies belief and threatens to
reignite debate about whether there is a scientific basis for thinking
homeopathic medicines really work.

A team in South Korea has discovered a whole new dimension to just about the
simplest chemical reaction in the book鈥攚hat happens when you dissolve a
substance in water and then add more water.

Conventional wisdom says that the dissolved molecules simply spread further
and further apart as a solution is diluted. But two chemists have found that
some do the opposite: they clump together, first as clusters of molecules, then
as bigger aggregates of those clusters. Far from drifting apart from their
neighbours, they got closer together.

The discovery has stunned chemists, and could provide the first scientific
insight into how some homeopathic remedies work. Homeopaths repeatedly dilute
medications, believing that the higher the dilution, the more potent the remedy
becomes.

Some dilute to 鈥渋nfinity鈥� until no molecules of the remedy remain. They
believe that water holds a memory, or 鈥渋mprint鈥� of the active ingredient which
is more potent than the ingredient itself. But others use less dilute
solutions鈥攐ften diluting a remedy six-fold. The Korean findings might at
last go some way to reconciling the potency of these less dilute solutions with
orthodox science.

German chemist Kurt Geckeler and his colleague Shashadhar Samal stumbled on
the effect while investigating fullerenes at their lab in the Kwangju Institute
of Science and Technology in South Korea. They found that the football-shaped
buckyball molecules kept forming untidy aggregates in solution, and Geckler
asked Samal to look for ways to control how these clumps formed.

What he discovered was a phenomenon new to chemistry. 鈥淲hen he diluted the
solution, the size of the fullerene particles increased,鈥� says Geckeler. 鈥淚t was
completely counterintuitive,鈥� he says.

Further work showed it was no fluke. To make the otherwise insoluble
buckyball dissolve in water, the chemists had mixed it with a circular
sugar-like molecule called a cyclodextrin. When they did the same experiments
with just cyclodextrin molecules, they found they behaved the same way. So did
the organic molecule sodium guanosine monophosphate, DNA and plain old sodium
chloride.

Dilution typically made the molecules cluster into aggregates 5 to 10 times
as big as those in the original solutions. The growth wasn鈥檛 linear, and it
depended on the concentration of the original. 鈥淭he history of the solution is
important. The more dilute it starts, the larger the aggregates,鈥� says Geckeler.
Also, it only worked in polar solvents like water, in which one end of the
molecule has a pronounced positive charge while the other end is negative.

But the finding may provide a mechanism for how some homeopathic medicines
work鈥攕omething that has defied scientific explanation till now. Diluting a
remedy may increase the size of the particles to the point when they become
biologically active.

It also echoes the controversial claims of French immunologist Jacques
Benveniste. In 1988, Benveniste claimed in a Nature paper that a
solution that had once contained antibodies still activated human white blood
cells. Benveniste claimed the solution still worked because it contained ghostly
鈥渋mprints鈥� in the water structure where the antibodies had been.

Other researchers failed to reproduce Benveniste鈥檚 experiments, but
homeopaths still believe he may have been onto something. Benveniste himself
doesn鈥檛 think the new findings explain his results because the solutions weren鈥檛
dilute enough. 鈥淭his [phenomenon] cannot apply to high dilution,鈥� he says.

Fred Pearce of University College London, who tried to repeat Benveniste鈥檚
experiments, agrees. But it could offer some clues as to why other less dilute
homeopathic remedies work, he says. Large clusters and aggregates might interact
more easily with biological tissue.

Chemist Jan Enberts of the University of Groningen in the Netherlands is more
cautious. 鈥淚t鈥檚 still a totally open question,鈥� he says. 鈥淭o say the phenomenon
has biological significance is pure speculation.鈥� But he has no doubt Samal and
Geckeler have discovered something new. 鈥淚t鈥檚 surprising and worrying,鈥� he
says.

The two chemists were at pains to double-check their astonishing results.
Initially they had used the scattering of a laser to reveal the size and
distribution of the dissolved particles. To check, they used a scanning electron
microscope to photograph films of the solutions spread over slides. This, too,
showed that dissolved substances cluster together as dilution increased.

鈥淚t doesn鈥檛 prove homeopathy, but it鈥檚 congruent with what we think and is
very encouraging,鈥� says Peter Fisher, director of medical research at the Royal
London Homeopathic Hospital. 鈥淭he whole idea of high-dilution homeopathy hangs
on the idea that water has properties which are not understood,鈥� he says. 鈥淭he
fact that the new effect happens with a variety of substances suggests it鈥檚 the
solvent that鈥檚 responsible. It鈥檚 in line with what many homeopaths say, that you
can only make homeopathic medicines in polar solvents.鈥�

Geckeler and Samal are now anxious that other researchers follow up their
work. 鈥淲e want people to repeat it,鈥� says Geckeler. 鈥淚f it鈥檚 confirmed it will
be groundbreaking鈥�.