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ANXIETY, stress and insomnia drive thousands of Britons to take tranquillisers
that may prove damaging in the long term. Now many people are turning to
alternative medicines with their alluring promise of natural remedies without
side effects. But how can the gentle fragrances of a treatment such as aromatherapy,
which involves massage with scented oils, match the potency of Valium or
Librium?

Researchers in the University of Warwick’s chemistry department believe
the answer is to sniff the ‘body’s own remedy’, a steroid molecule in human
sweat which they claim alters mood much as tranquillisers do. This molecule,
named Osmone 1, is chemically similar to other animal musks and to components
of sandalwood oil. These substances are almost universally attractive to
our sense of smell and have been used for centuries in medicines and perfumery.

Aromatherapy has traditionally exploited the power of odorants to influence
mood, but the choice of ingredients has been largely intuitive and arbitrary.
George Dodd and Don Jenkins, co-directors of Warwick’s olfaction research
group, argue that the principles of aromatherapy can now be transformed
into an exact science. The key, they claim, is to use ‘nature’s own tranquilliser’.

Dodd and Jenkins use the term osmotherapy to describe the use of natural
human odours as self-help treatments for stress and anxiety. So convinced
are the Warwick researchers of the effectiveness of Osmone 1, that their
company, Osmotherapy Ltd, based at the university’s Science Park, is about
to launch a manufactured commercial product. It will be sold under the tradename
Relax from next month, at Pounds sterling 17.50.

Warwick has become a world centre for olfactory research through innovations
such as an ‘electronic nose’ that can monitor the balance of beer ingredients
by sniffing its aroma, and ‘smell kits’ developed for the Royal National
Institute for the Blind to help blind children to increase their olfactory
powers. But compared with research on sight and hearing, the sense of smell
has been neglected. Olfaction is mediated by the primitive limbic system,
the brain’s control point for mood and emotion, and is deemed to have been
upstaged in evolutionary terms by sight and sound, analysed by ‘higher’
centres in the cerebral cortex. Yet recent research suggests this explanation
may owe more to culture than to biology.

Sigmund Freud first suggested the concept of ‘organic repression’ of
smell, which he dated to the time humans began to walk upright. He argued
that among early hunter-gatherers, olfactory bonds between partners became
less effective because they were linked to the menstrual cycle and were
thus intermittent. So as humans evolved, smell took second place to sight,
and bonds became based on visual appearance.

Yet despite this ‘repression’, humans of all cultures have experimented
with aromatic plants and the resins and gums from trees, which are high
in what aromatherapists call essential oils. Many seemed to offer medicinal
benefits, but others were apparently enjoyed for their scent alone.

Michael Stoddart, a zoologist at the University of Tasmania, has suggested
that once repression banished the role of smell in sexual bonding to the
unconscious mind, it became ‘safe’ for people to indulge the mood-altering
effects of scent which lingered on like an echo in the limbic system. Apparently
this echo is sounded most resonantly by the odour of animal musks, particularly
when mixed with plant oils such as frankincense, myrrh and sandalwood. Together,
they form an intoxicating combination. Hence the central paradox of perfumery:
why should humans have such an unexpected liking for the rather pungent
odour produced by a small deer from Tibet?

Part of the answer is that a molecule of steroid musk, such as Warwick’s
Osmone 1, is shaped very like the male sex hormone testosterone. It also
resembles the phytosterols, which are related to animal sterols and found
in sandalwood and other plants. All steroid-like molecules have a distinctive
odour, to which women are a thousand times more sensitive than men.

The rest of the answer is emerging from research into the much maligned
products of the human armpit – the axilla to biologists. Researchers have
found that two steroids produced by the action of bacteria on human sweat
are particularly influential on our behaviour.

In one experiment in the late 1970s, Tom Clark, then of Guy’s Hospital
Medical School in London, and his colleagues sprayed a odorous steroid,
5-alpha-andosterone, on unreserved seats in a theatre. They found that these
seats were occupied mainly by women and that none of the empty seats had
been sprayed. Furthermore, women working in the theatre, whose menstrual
cycles were usually synchronised, also found that the experiment disrupted
the synchronicity. Intriguingly, men produce much higher levels of 5-alpha-androstenone
than do women.

At about the same time, Michael Kirk-Smith, David Booth and their colleagues
from the University of Birmingham asked people subjected to the odour of
another steroid, 3-alpha-androstenol, to give opinions on a series of photographs.
The subjects who smelled the steroid judged photographs of women to be more
attractive than did other people who were not exposed to the odour.

The Warwick team is interested in behavioural effects that take place
at a much earlier stage of human development. There is growing evidence
that new-born babies, whose visual abilities are limited, may rely on olfactory
communication with their mothers during the all-important bonding process.
Jennifer Cernoch and Richard Porter of Vanderbilt University in Nashville
established in 1985 that breast-fed babies recognise their mother by odour
more readily than bottle-fed babies. At a week old, a baby can discriminate
between a gauze axillary pad worn by its breast-feeding mother and another
worn by a control. Bottle-fed babies are apparently unable to do this. More
often than not, mothers can also select the clothes worn by their babies
from a pile of similar items.

Cernoch and Porter argue that such results underline the importance
of biological odours in influencing human social behaviour. Babies begin
to distinguish the sound of their mother’s voice on the third day after
birth and start to recognise her face when they are a few days old. Dodd
points out that the sense of smell is fully functional from birth and possibly
even before. He argues that this makes an olfactory cue a likely key component
in the formation of social relationships.

Dodd believes the key chemical messenger involved in this process is
Osmone 1, a possible progenitor of 5-alpha-androstenone and a contributor
to the subliminal smell of clean, fresh skin. This is secreted through sebaceous
glands on most parts of the body, but concentrated in areas such as the
armpits and mammary glands. Babies may use its distinctive odour to identify
their mother, but Dodd argues that in its role as a natural tranquilliser
the compound is acting as a pheromone – a chemical messenger that produces
a specific metabolic effect in the individual receiving it.

Here there is much disagreement. Some believe odour is significant to
humans only when it forms a strong mental association with good or bad life
events. Others believe a clear cut pheromonal effect can directly override
a person’s conscious intentions. In other words, are responses to biologically
important odours soft-wired or hard-wired into the human brain? At one end
of the continuum are psychologists who believe that the odours themselves
are no more than epiphenomena. Trygg Engen at Brown University, Rhode Island,
for example, argues that the strength of the human olfactory system is flexibility:
any kind of useful association can be remembered for future reference. He
quotes the example of novelist Marcel Proust in whose novel Remembrance
of Things Past vivid memories of a happy childhood are instantly recaptured
by the smell of a Madeleine biscuit dipped in a cup of tea. Engen argues
that the odour involved in the social bond between mother and child is just
as arbitrary as the smell of biscuit: the bond is not caused by the odour,
but by the positive and rewarding nature of the association between the
two.

David Booth of the University of Birmingham agrees, and argues that
people react to androsterone because, consciously or unconsciously, they
recognise its similarity to personal fragrances or perfumes. He believes
that there are no convincing examples of true pheremonal effects, apart
from studies of insects. A mammal’s typical responses to smells are all
learnt, he says. K K If, as Booth argues, we have learnt to associate a
certain smell with a certain emotion, particularly odours could quickly
lose their appeal. ‘I question the value of repeatedly using an odour in
the content of a chronic condition such as anxiety,’ he says. The positive
association between an odour and emotion could fade, to be replaced by a
negative one in the light of new experience.

But Dodd believes that each species, including Homo sapiens, has its
own unique chemical messengers. Why else, he asks, should humans have so
many sebaceous glands, strongly concentrated in hairy areas, whose surface
area helps to distribute odour as effectively as possible? Among the primates,
only the lemur has as many such glands.

Numerous examples demonstrate the importance of olfactory messengers
among animals, and at least some of these responses may be ‘innate’. Rats,
for instance, are frightened by an isolated fox odorant, even if they have
never had contact with the animal. But Dodd argues: ‘The animal odours which
have the most behavioural significance are those that are restricted to
one species. What excites a dog doesn’t necessarily excite a cat. So the
most significant smells for humans should be ones we ourselves produce.
Nature has designed them for us.’

These chemical messengers might be recognised by the brain via special
receptors on nerve cells that lead directly along the olfactory tract to
the limbic system. So far, evidence for such molecule-specific receptors
is limited but increasing. At Warwick, Ernest Polak is now trying to study
receptors with monoclonal antibodies: if there are specialist receptors,
their action should be selectively blocked by the appropriate antibody.

Even if there is no proof yet of specialist receptors for Osmone 1,
we do know that humans are more sensitive to certain odours than others.
Only six of the 12 steroid ordorants in human sweat are comparatively well
studied. Their smell is not usually noticeable until bacteria acts on them,
yet they could still be influential on human relationships. Dodd says: ‘The
effect is very subtle. It would not occur to you that you don’t get on with
someone because of a normal level of body odour. You would put it in other
ways, such as you don’t like the way they look at you or talk to you. This
is partly to do with the way we are educated.’

Even the pungent odour of 5-alpha-androstenone, for instance, produced
after bacteria break down sweat, occurs in just one part per billion. Chemists
can measure the amounts in the air only with the aid of sophisticated techniques
such as gas chromatography and mass spectrometry. But such studies reveal
that people differ markedly in their ability to detect this odour; in a
study at Guy’s Hospital in London, people reported smelling it at levels
between 0.2 parts per billion and 0.2 parts in 100 million.

Such thresholds are hard to comprehend. Dodd puts them in context using
a substance we are particularly sensitive to – galbanum, one of the eight
incense ingredients the Old Testament says God instructed Moses to include
in a holy perfume. If just one drop of galbanum from the end of a needle
splashed into an Olympic-size swimming pool, someone sniffing the water
could detect the distinctive, earthy green pepper smell.

Human odours are a thousand times less powerful than this, but the effect
is still impressive. How is it achieved? Galbanum and 5-alpha-androstenone
have ‘flat’ intensity curves – their odorant quality persists at a constant
level however much they are diluted. But many pungent odours such as ether
rapidly increase in intensity to a ‘smell peak’ as their concentration in
air rises, and then recedes.

Early research suggested surprisingly that many people could not detect
the smell of 5-alpha-androstenone at all. More recently, studies by Steve
Van Toller at Warwick, measuring skin conductance, suggest it is detected
far more widely. Some people who said they could not detect the odour showed
an unconscious response in the skin conductance test. This has been attributed
to the common difficulty of finding words to express smells, possibly because
the sensory messages involved are interpreted far from the speech centres
of the brain.

Part of the limbic system, the hippocampus, has long been implicated
in the formation of long-term memory. So perhaps it is the source of deja
vu experiences such as Proust’s, evoked so vividly and instantly by an apparently
long forgotten smell. How the brain interprets olfactory messages is not
yet clearly understood and the Warwick team is seeking funding for further
research in this area.

Although knowledge is still imperfect, Dodd does believes the therapeutic
potential of molecules such as Osmone 1 should be exploited. ‘It is after
all only about 10 years ago that we discovered how aspirin works,’ he says.
If it works, Osmone 1 could have a major advantage over tranquillising drugs:
it will not build up in the bloodstream and cause harmful dependence effects.
In odour therapy, the molecules are expelled from the body after less than
100 milliseconds, as soon as their chemical message is delivered and translated
into an electrical signal transmitted to the brain. Glue sniffing is harmful
because the sniffers repeatedly draw in large quantities of molecules which
enter the bloodstream through the vascularised area of the nose.

Osmone l’s potential as a substitute for tranquillisers emerged during
trials among anxiety sufferers over a two-month period. Hundreds of volunteers,
many of whom were taking traditional drugs, sniffed a cassette containing
the odorant four times daily. The cassette is made up of a network of tubes
and sponges and operates through a wick delivery system, with Osmone 1 contained
in a solvent. The whole thing is small enough to fit into the palm of a
hand. It is non spillable and the smell cannot be detected by anyone else
standing nearby.

Volunteers were asked to complete mood evaluation forms at the end of
each week of the trial. The forms were carefully varied to avoid volunteers
falling into a set pattern of response. Dodd says: ‘Nearly everyone reported
an improvement in their symptoms. Some have been able to reduce the dosages
of tranquillisers they take. We know that many people taking tranquillisers
don’t need them and wish to avoid them.’ But of course these trials do not
rule out that improvements were due to the ‘placebo effect’, but it is difficult
to set up ‘double-blind’ experiments for such remedies.

Odour cassettes have also been tested by anxiety sufferers at a cognitive
behavioural therapy unit in Coventry. Judith Johnson, mental health section
supervisor at the Coundon Care Centre Charity, has monitored the progress
of seven people using the cassettes compared to a similar group receiving
therapy only. Those in the cassette group who were also taking tranquillisers
have been able to reduce their dosages or stop taking them altogether. Agoraphobics,
whose anxiety prevented them visiting public places, have learnt to do so
without distress.

‘All of them say they are sleeping better and feel more relaxed. There
is a big difference compared to the others,’ says Johnson. However, two
people whose anxiety is related to bouts of depression have not reported
any relief from those symptoms and are still taking anti-depres sant drugs.

Most of the trial group could not smell anything from the cassettes
for the first two weeks, but all could detect something by the end of the
trial period. They describe Osmone 1 as having a musky or sandalwood odour.
Dodd attributes this delay to atrophy of neuronal circuits which in early
life were highly tuned to the odour. It takes training, he argues, to reactivate
the system.

The Warwick team believe osmotherapy will also be able to help people
to give up smoking. They are working on a formula which will enable people
to enjoy the flavour of tobacco, through smell, while avoiding the heavy
ingestion of nicotine and tar involved in smoking. ‘This will enable people
to give up smoking in two stages,’ says Dodd.

They are also now developing what they hope will be an effective appetite
suppressant. This research is focusing on a heterocyclic molecule, also
found in body secretions, which suppresses salivation and makes food seem
repellant. ‘One of the few times when people actively use their sense of
smell is when they are testing food,’ says Dodd. ‘This osmone will be used
as a binary weapon by combining it with other odours which will play pleasant
tunes on the consciousness. The real message will get through at a subliminal
±ô±ð±¹±ð±ô.’

How does osmotherapy compare to aromatherapy? Aromatherapists claim
that their power lies in the use of natural, non-synthetic essential oils
which are seen as containing the ‘life force’ of the plant within a balance
of constituent elements. Practitioners of aromatherapy would argue, for
example, that a 1 per cent dilution of clove oil is three or four times
more effective an antiseptic than its main component, eugenel, acting alone.

Dodd claims that essential oils are not ‘natural’ because they are distilled
and that the standard of purification makes their action in the body uncertain.
‘Purity is everything when it comes to odours. If you get something 99.9
per cent pure, the contaminant can dominate.’ A so-called essential flower
oil may contain as many as 400 distinct odorants. The synthetic form of
Osmone 1 will be an exact chemical replica of the original.

Dodd says that the magic ‘life force’ ingredient attributed to aromatherapy
treatments lies in the dynamism of me tabolites working together in a living
process. Massage is also important in aromatherapy, when around 0.1 milli
litre of the essential oil is absorbed through the skin into the bloodstream,
about the same as would be used in an oral therapeutic dose.

Dosages are controversial in aromatherapy. Sometimes, low dosages apparently
reverse a sedative into a stimulant. Or very small dosages may have an equal
effect to a very large dose, rather like homeopathy, whose practitoners
claim that the more a substance is diluted, the more potent it becomes.

Some of aromatherapy’s claims for its ingredients are now being validated.
Researchers from the Toho University School of Medicine in Tokyo, for instance,
have tested a number of essential oils used in aromatherapy by a technique
known as contingent negative variation (CNV). Electrodes attached to the
scalp monitor upward shifts in brain waves, and results are averaged over
10 to 20 trials.

They found that when people are subjected to the odour of jasmine, said
to be a stimulant, CNV amplitude increases. CNV waves are meant to indicate
that a person is alert or paying attention to something. It also consistently
goes down when people are exposed to lavender, which is con sidered a sedative.
At the same time, the researchers monitored reaction time, heart rate and
level of sleepiness or alertness and found these did not vary. The stimulant
caffeine speeds up reaction time and central nervous system depressants
such as the anti-psychotic drug chlorpromazine slow reaction times.

The Japanese researchers went on to test 17 other essential oils and
found that the CNV readings corresponded to the properties attributed to
them in the majority of cases. One exception was rose oil, usually regarded
as a sedative, which increased CNV.

Apart from experiments such as these, the value of aromatherapy remains
largely anecdotal, and the recent enthusiasm for ‘mood fragrances’ sold
alongside cosmetics threatens to taint it with a whiff of quackery. But
if the experience of practical trials and continuing research validates
the principles of osmotherapy, this may be a first step towards providing
at least one branch of alternative medicine with a new authority.

Annabelle Birchall is a freelance journalist based in Sussex.