"Carotenoids" is the term which describes the large range
of more than 600 pigments which give many plants their
characteristic red, orange or yellow colouring. Amongst
those most commonly found in modern Western diets are
alpha-carotene, beta-carotene, lutein, zeaxanthin, and
lycopene.
Most attention has been paid to alpha-carotene and
beta-carotene as these can be synthesised by the body to
form vitamin A, which is one of the body's most powerful
antioxidants, immune system boosters and infection
fighters. Neither lutein, zeaxanthin nor lycopene are
"pro-vitamin A" active substances in this sense, but this
should not be taken as detracting from their nutritional
value in any way.
Indeed, the evidence now indicates that these lesser known
carotenoids also function as valuable fat-soluble
anti-oxidants within the body. Lycopene, in particular, is
now even thought to be responsible for many of the
anti-oxidant functions previously credited to
beta-carotene. Research suggests that as a highly
fat-soluble anti-oxidant, lycopene is particularly
important in preventing free radical damage to the delicate
but vital fatty structures of the body's cells, such as the
membranes.
It also seems possible that lycopene may be at least as
important as beta-carotene in protecting against the
oxidation of Low Density Lipids (LDLs), the so-called "bad
cholesterol", which is now widely held to be a principal
cause of atherosclerosis, or hardening of the arteries -
the precursor of serious cardio-vascular diseases such as
heart attack and stroke.
Like beta-carotene, lycopene has also generated much
excitement as a potential weapon against cancer, probably
because of its general anti-oxidant function, but also
because of its proven role in keeping open the pathways
between cells which are vital to allow the immune system to
kill off cancer cells in the early stages of the disease.
In 1995 the Journal of the National Cancer Institute
reported research suggesting a 45% reduction in rates of
prostate cancer for men consuming a lycopene rich diet – ie
one containing considerable quantities of processed
tomatoes. Other studies have since indicated a role for
lycopene in combatting lung, stomach, colon and breast
cancer; in protecting against cardiovascular disease, and
as an immune system booster.
Unfortunately the consumption of a diet rich in lycopene
presents practical problems which do not arise with the
better known carotenoids, alpha and beta-carotene, because
it is not nearly so widely available in common foodstuffs.
It is lycopene which gives tomatoes their characteristic
vivid red colour, and it is this fruit which is by far the
richest source. But it is the processing and/or cooking of
tomatoes which makes available far more lycopene than would
be provided by the raw fruit.
So a cup of regular tomato paste may contain more than
75,000 mcg of lycopene, tomato puree more than 50,000, a
regular can of tomato soup more than 25,000 and canned
tomato juice perhaps 20,000. A serving of raw tomatoes, by
contrast, will provide a mere 5,000. So rather than rely
on raw tomatoes, unless you can consume truly heroic
quantities, you'd do better to try a cup of canned mixed
vegetable juice at around 23,000 mcg or even a slice of
watermelon which may yield up to 13,000 mcg.
The above figures make it clear that processed tomatoes are
the best source of significant dietary lycopene, but the
problem with this from the point of view of the health
purist is that the processing of tomatoes into soup, paste
or puree commonly involves the addition of considerable
amounts of salt and sugar – just what your body doesn't
need if you're seeking extra protection for your heart and
circulatory system.
It also needs to be remembered when planning a lycopene
rich diet that, as with other carotenes, the optimum
absorption requires the presence of dietary fat. This is
not so easy to achieve with tomatoes unless you're thinking
about the rich kind of meat and tomato sauce commonly eaten
with pasta, or smothering a fatty meal with ketchup.
Nothing wrong with either option in moderation of course,
but they're hardly healthy ways to get the lycopene you
need every day.
So tomato juice in the purest form possible is probably the
best means of obtaining significant dietary lycopene. That
Bloody Mary with accompanying potato chips may be doing you
some good after all!
Supplements containing lycopene are also readily available
as an alternative, but opinions are divided as to their
effectiveness. Conventional medicine tends to accept the
value of a diet rich in carotenoids, but argues that the
positive effects may be due to factors associated with such
diets other than the carotenoids themselves. Alternative
practitioners, of course, admit to no such doubts and are
therefore convinced of the benefits of specific carotenoid
supplementation.
So as ever, the commonsense advice for maximum benefit
appears to be to combine supplementation with a normal
daily diet already well supplied with lycopene rich foods.
----------------------------------------------------
Steve Smith is a freelance copywriter specialising in
direct marketing and with a particular interest in health
products. Find out more at
http://www.sisyphuspublicationsonline.com/LiquidNutrition/In
formation.htm
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