"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.
Vitamins
Products - Liquid Nutrition
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.
Healthy
Living
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.
Check
out our Healthy Blog!
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.
