Bizarre chemical discovery gives homeopathic hint
November 07, 2001
Exclusive from New Scientist Print Edition
It is 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 - what 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 neighbors, 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
Some dilute to "infinity" until no molecules of the remedy remain. They
believe that water holds a memory, or "imprint" of the active
ingredient which is more potent than the ingredient itself. But others use less
dilute solutions - often 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. "When he diluted the
solution, the size of the fullerene particles increased," says Geckeler.
"It was completely counterintuitive," 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 five to 10 times as big as
those in the original solutions. The growth was not linear, and it depended on
the concentration of the original.
"The history of the solution is important. The more dilute it starts, the larger the
aggregates," 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 -
something that has defied scientific explanation till now. Diluting a remedy
may increase the size of the particles to the point when they become
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 "imprints" in the water structure where the antibodies had
Other researchers failed to reproduce Benveniste's experiments, but homeopaths still
believe he may have been onto something. Benveniste himself does not think the
new findings explain his results because the solutions were not dilute enough.
"This [phenomenon] cannot apply to high dilution," he says.
Fred Pearce of University College London, who tried to repeat Benveniste's
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.
"It's still a totally open question," he says. "To say the
phenomenon has biological significance is pure speculation." But he has no
doubt Samal and Geckeler have discovered something new. "It's surprising
and worrying," 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.
"It doesn't prove homeopathy, but it's congruent with what we think and is very
encouraging," says Peter Fisher, director of medical research at the Royal
London Homeopathic Hospital.
"The whole idea of high-dilution homeopathy hangs on the idea that water has
properties which are not understood," he says. "The fact that the new
effect happens with a variety of substances suggests it's the solvent that's
responsible. It's in line with what many homeopaths say, that you can only make
homeopathic medicines in polar solvents."
Geckeler and Samal are now anxious that other researchers follow up their work. "We
want people to repeat it," says Geckeler. "If it's confirmed it will
Journal reference: Chemical Communications (2001, p 2224)