http://www.healthsentinel.com/news.php?event=news_print_list_item&id=689
"Cholesterol feeds prostate cancer", BBC News, March 18, 2005,
Link: http://news.bbc.co.uk/2/hi/health/4359117.stm
High cholesterol levels accelerate the growth of prostate tumours,
research has found.
A team from Boston's Children Hospital also found that
cholesterol-lowering statin drugs may inhibit prostate cancer growth.
The findings may help explain why prostate cancer is more common in the
West, where diets tend to be high in cholesterol.
Details are published in the Journal of Clinical Investigation.
Rates of prostate cancer in rural parts of China and Japan, where low
fat diets are the norm, are up to 90% less than in the West.
Yet when Eastern men migrate to the West their chances of being
diagnosed with prostate cancer increase.
This has led doctors to suspect that environmental factors - such as
diet - may play a significant role in the development of the disease.
Mice experiments
The Boston team injected human prostate cancer cells into mice and
watched them grow.
When the animals were fed high cholesterol diets, cholesterol was found
to accumulate in the outer membranes of tumour cells.
This appeared to alter chemical signalling patterns within the cells.
As a result, they resisted signals telling them to commit suicide and
instead continued to proliferate in the uncontrolled fashion seen in
cancer.
The increased cholesterol levels did not trigger new cancers in the
mice.
But six weeks after the tumour cells were injected, mice on the
high-cholesterol diets had twice as many tumours as animals on ordinary
diets.
Their tumours were also much larger in size.
When the cells were exposed to the cholesterol-lowering drug
simvastatin, cell death increased and tumours stopped proliferating.
But replenishing cell membranes with cholesterol caused the cancer to
run out of control again.
Lead researcher Dr Michael Freeman said: "Our study opens up a new
paradigm in thinking about how cancer might be controlled
pharmacologically by manipulating cholesterol.
"Our data support the notion that cholesterol-lowering drugs - which
are widely used and fairly safe - might be effective in prevention of
prostate cancer, or as an adjunctive therapy."
Chris Hiley, of the UK Prostate Cancer Charity, said: "This research is
clearly at an early stage, as it was accomplished in mouse cells, not
men, but it's heartening to see a plausible connection made between
processes inside cells and the Westernised high fat diet that seem to
increase the risk of prostate cancer occurring.
"The results do open up thinking about new drug therapies.
"But there is also a low tech option any man could attempt today.
"Adopt a healthy low cholesterol diet and active lifestyle.
"Cut down on saturated fats, reduce the total amount of fat eaten but
eat oily fish, and eat a high fibre diet - with porridge oats, and
plenty of fresh fruit and vegetables."
Every year 27,000 men are diagnosed with prostate cancer and 10,000 men
die from it.