Cholesterol a ‘magnet’ to prostate cancer- so do we put down that butter?
A high-cholesterol diet might increase the spread of prostate cancer, according to new findings from former Worldwide Cancer Research grant holder Dr Michelle Hill and her team at the University of Queensland in Australia.
So does this mean that butter is out (again)?
What did the research find?
The researchers fed groups of mice with advanced prostate cancer either a high-cholesterol or low-cholesterol diet, and then compared how the tumours progressed over time in each group.
They found mice fed a high-cholesterol diet had increased spread of prostate cancer tumours to lymph nodes, lungs and bones.
“High cholesterol doesn’t change the size of the original prostate cancer tumour,” said Dr Hill, “but the effect on cancer spreading was shown to be significant.”
The researchers were also able to identify some of the background cell mechanisms behind this effect.
“We found two key proteins which enable the high cholesterol to prompt cancer spreading,” said Dr Hill. “Cholesterol acts like a magnet, pulling these two proteins to the surface of the cancer cell. This disrupts the function of the cell, makes it more aggressive and spreads it elsewhere in the body.”
So the butter goes?
Not quite yet. While providing very valuable evidence about how cholesterol can modulate cancer cells, remember this research was done in mice, and a great deal more research is needed to understand exactly how cholesterol and cancer might interact in humans.
The question of cholesterol and prostate cancer is a tricky one. Some observational studies have reported that certain groups of people with high levels of a type of cholesterol in their blood may have an increased risk of developing prostate cancer. And other findings suggest that some patients with prostate cancer who took cholesterol-lowering drugs (called statins) had delayed prostate cancer progression and death.
However other studies are less positive. They suggest cholesterol-lowering drugs may only be of benefit to specific groups of patients at certain stages, or might even have no benefit at all. Results are mixed, and potential benefits of statins or other cholesterol-lowering drugs in prostate cancer are still very much in debate.
The problem is that unlike well-controlled, well looked after lab mice, humans are messy creatures. Much of the research findings in humans mentioned above come from necessarily imperfect observational studies, where aspects of lifestyle and health of a group of people are surveyed over time, to try and capture any links and patterns between the two. It can be very hard to prove a cause and effect between a single factor, like cholesterol, and a single condition, like cancer.
Well-designed, randomised controlled trials will help to pin down exactly what, if any, benefit new and existing cholesterol-modulating drugs might bring to cancer patients. But there also needs to be continuing focus on basic, cellular level research like Dr Hill's.
If scientists can uncover exactly how cholesterol and other similar fatty molecules might affect the activity of cancer cells at the molecular level, this research can ultimately underpin new prevention and diagnosis strategies, and help define which patients might benefit in clinical trials.
And more importantly, research like Dr Hill's can help open up completely new avenues for treating prostate cancer. Dr Hill says of her team’s findings: “If we can block the magnetic effect cholesterol has on these two proteins, our research could lead to future treatments preventing the spread of prostate cancer.”
Much as the newspapers would like, early-stage research can't tell us whether to put down that butter or not. But it can get us on the right path to some real answers. Even better it can open up new paths that until now have remained hidden.
Dr Hill's research is published in the journal Oncotarget .
Search our project database for more prostate cancer research.
Read about one of our newest projects investigating how obesity might lead to liver cancer.
Dr Hill’s study was funded by Worldwide Cancer Research and the Prostate Cancer Foundation of Australia.