We
all know that steaming vegetables is meant to be better than the
old-fashioned method of boiling them to a mush. It's something to do with
keeping the vitamins and minerals intact and preventing them from simply
being washed out of the veggies and into the pan. Now, Korean chemists have
found that steaming the Asian herbal pick me up ginseng for a couple of
hours during the manufacturing process can boost its supposed revitalising
power by about eight times. Researcher Jeong Hill Park of the college of
pharmacy at Seoul National University in Seoul, in South Korea, has found
that rather than preparing ginseng at boiling water temperature if it is
steamed for about three hours at 120 degrees Celsius under pressure the
antioxidant qualities of the herb can, he says, be increased by some eight
times and its ability to relax blood vessels is improved by up to 32 times.
Park believes the higher temperature helps to amplify the active
ingredients in ginseng by modifying the chemical structure of the natural ginsengosides contained in the roots These compounds, known chemically as
saponins, are believed to be responsible for ginseng's much sought-after
health-giving qualities. Additional active compounds are released by
steaming that are not normally found in dried versions of the root, Park
says. 'This very simple steaming can significantly increase the biological
activities of ginseng,' Park explains,' I believe we can develop more
potent health foods or related products using this process.' So, it might
be possible to get the same health and mental enhancement from a smaller
amount of steamed ginseng.
Extracts from the fleshy root of the perennial Ginseng plant - which grows
in the undergrowth of deciduous forests - have been used in traditional
oriental medicine for many centuries. Oriental ginseng (Panax ginseng) is
prepared from the roots bleached, boiled, the red variety is steamed at 100
Celsius, and sometimes sugared. It can be used to make a tea or simply
chewed. In the West it is sold in a convenient capsule form, which you
simply swallow. Phenolic compounds also found in ginseng, increase during
steaming too, says Park, and these act as antioxidants, mopping up damaging
free radicals from the body's cells. The root also acts to relax the walls
of blood vessels and block the blood-clotting compound thromboxane so
'thinning' the blood.
The history of the herbal root is thought to stretch back to the fourth
century BC and there is evidence that many of the 22 or so different known
varieties, which grow naturally from Manchuria and Korea by way of Russia to
the USA and Canada (Panax quiquefolius) have been used in traditional native
medicines for many centuries. Even the distantly related plant known as
eleuthero or Siberian ginseng (Eleutherococcus senticosus) has its
proponents. Many people swear by ginseng's curative properties. It can, it
is claimed, increase general vitality, improve memory, lower cholesterol,
give the immune system a kick-start, and even help fight diseases such as
cancer, and treat angina and cardiovascular disease. Many users see it as a
natural Viagra, providing them with a pick-me-up in the bedroom too.
With all these amazing properties ginseng is big business with sales of
more than $100 million in the USA every year and an increasing number of
users in Britain.
So, is ginseng a panacea and should we all be taking it or is it simply
another money-spinner for big business jumping on the 'natural health' gravy
train? A systematic review of the medical literature by a team of
researchers into complementary medicine at Exeter University led by Ezard Ernst concluded that the evidence for whether or not ginseng
works is inconclusive.
The team looked at the various trials that have been carried out on
its effects and found that there were often conflicting results. One study
might show an effect in a few patients with a specific disease while
another found that a placebo worked just as well if not better. For
instance, they looked at the results from five trials, with 19 to 127
participants. Four of the studies were with healthy volunteers and three
of these found some benefit to using ginseng in the participants' ability
to do an arithmetic test. While for elderly patients, ginseng was no
better than placebo.
Park believes the reason researchers have found conflicting results
for the efficacy of ginseng is that there are two types of ginsengosides.
'One type is the 'panaxadiol' PD type and the other is panaxatriol (PT)
type,' he explains, 'sometimes these two kinds of ginsengosides have
conflicting activity in the body so some researchers observe antagonist
activity while others see agonist activity, both effects are usually very
mild.' He adds that better experimental design might help show the
positive effects of ginseng, 'I believe the conflicting reports on the
biological activity of ginseng results from the different experimental
model or, in some cases, inadequate experimental design.'
'I strongly believe that the ginseng is very useful for the
prevention of many diseases in adults and incurable diseases,' enthuses
Park. 'Ginseng has few side-effects and has proven itself through its long
history in the Orient and also through modern toxicological studies.'
So, ginseng might indeed be a panacea and the super-steamed variety
could be even better. But, be on the safe side, check with your doctor if
you are on any medication before taking the cure-all or if you are
pregnant or suffer from hay fever, asthma, emphysema, high blood pressure,
blood-clotting problems, heart disorders or diabetes and don't exceed the
recommended dose.
Park and his colleagues report their results in more detail in the
current issue of the Journal of Natural Products.