Prostate tumours shrunk by lycopene, vitamin E combo

[email hidden] wrote:

: Consequently, the mice receiving the combined supplement also lived 40
: per cent longer than the placebo group.

That is impressive.

--
Juhana

Do you know what form of alpha tocopherol these researchers used, i.e.
synthetic (d + L in equal concentrations, typically) or natural (entirely
d-alpha tocopherol, since plants are much cleverer, or more precisely, their
Designer was much cleverer, than the usual designers of chemical synthesis
process plants of the human-designed sort) ? According to most nutritional
therapy experts, only the d stereoisomer is therapeutically effective, and
the L stereoisomer may actually be harmful and certainly is not particularly
useful. I have seen differing opinions on whether pure alpha tocopherol
or mixed tocopherols are more effective, and I have seen allegations that
pure alpha tocopherol is more likely to produce unpleasant cardiac side-
effects. E.g., vitamin E has a reputation for exacerbating problems with
hypertension in those who already have a tendency to it. I am not sure if
the forms of tocopherol other than alpha are less troublesome precisely
because they are biologically less active than alpha or for some other
reason. Incidentally, some of the old-time experts in nutritional therapy
were highly critical of early tests of the efficacy of vitamin E because
those tests used mixed tocopherols and synthetic ones at that, thus a mixture
which these experts said had long been known (and this was a long time ago!)
to consist of only about 5% useful, active ingredient (namely the d-alpha
form, which they said was known to be the only one that is useful for
therapeutic purposes). I think there was suspicion that whoever funded
that particular test did not want vitamin E to be shown to be useful.

I wonder if the researchers whose work you summarized mentioned any of
these additional issues, at least the objective scientific ones?

I think it is very positive that they are looking at combinations of
nutrients. This gets progressively harder to do as you include more and
more different kinds of molecules, but that is a separate question from
whether or not it is important to understand the interactions... as
this study illustrates.

-John S.,
Wellesley Hills, MA
------------------------
In article <[email hidden]>,

Quoted message said:

http://www.nutraingredients.com/news/ng.asp?n=67083-lycopene-vitamin-e-prostate-cancer

Prostate tumours shrunk by lycopene, vitamin E combo

By Stephen Daniells

14/04/2006 - A combination of lycopene and vitamin E suppressed the
growth of prostate cancer in mice, but had no effect when used
independently, say Dutch researchers.

The role of tomato and its extracts to protect against prostate cancer
has been reported in several epidemiological studies, which lycopene
supplement producers have been quick to promote. The new research, led
by Professor Wytske van Weerden from Erasmus MC in Rotterdam, casts
doubt on the effectiveness of lycopene by itself, and suggests a
synergetic effect with vitamin E, another nutrient naturally found in
tomatoes.
The study, published in the May issue of the Journal of Nutrition (Vol.
136, pp. 1287-1293), followed the effects on differing supplementation
doses and combinations of lycopene and vitamin E on 54 mice inoculated
with prostate cancer cells.

The mice were divided into six equal groups. The mice were fed a
standard low vitamin E rodent diet, and three days after inoculation
the diet was supplemented with one of the following: nothing (placebo);
lycopene only (5 milligrams per kilogram of body weight (mg/kg BW) or
50 mg/kg BW); vitamin E only (5 mg/kg BW or 50 mg/kg BW); or vitamin E
plus lycopene (5 mg/kg BW each).

BASF provided both nutrients: lycopene was provided as LycoVit 10 per
cent, and vitamin E as alpha-tocopherol 50 per cent powder.

The researchers found that, after 95 days of supplementation, none of
the single supplements, regardless of dose, had any effect on the
tumour size.

"Compared with the control, the combined mixture of lycopene and
vitamin E, at five mg/kg BW each, suppressed the growth of the prostate
xenograft by 73 per cent at day 42," wrote lead author Jacqueline
Limpens.

Consequently, the mice receiving the combined supplement also lived 40
per cent longer than the placebo group.

While the single supplements did not effect tumour size, the group
receiving five mg/kg BW of lycopene did show slower tumour growth and a
19 per cent longer survival rate.

The researchers also reported that levels of the so-called prostate
specific antigen (PSA), a protein that is used as a marker for the
disease, tended to be lower in the combo supplement group. Plasma PSA
levels were proportional to tumour size for all groups, adding support
for the use of PSA as a marker of the disease.

Previous research has linked the benefits of tomatoes to the lycopene
content of the fruit, conclusions that are not in-line with the results
of Limpens and her colleagues.

Indeed, it appears as if lycopene and vitamin E exert a cooperative
interaction to protect against prostate cancer growth. The mechanism,
say the researchers, remains speculative but could be due to lower
oxidative stress, altered hormone and growth factor signals, or
apoptosis (programmed cell death).

"On the basis of our findings... we are currently assessing the
effects of lycopene-vitamin E supplementation on rising PSA-levels in
an exploratory phase II clinical prostate cancer trial," said the
researchers.

According to the European School of Oncology, over half a million news
cases of prostate cancer are diagnosed every year world wide, and the
cancer is the direct cause of over 200,000 deaths. More worryingly, the
incidence of the disease is increasing with a rise of 1.7 per cent over
15 years.

Who loves ya.
Tom

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