For a long time experts have warned us prostate cancer patients to limit or eliminate consumption of dairy foods. In fact "The China Study," a fairly recent widely read book, focused a lot of attention on possible links between dairy foods and various cancers.
However, recently one of the leading experts in prostate cancer and nutrition modified his stand on dairy, writing that it was probably a fairly minor factor and not a major player.
Now we have a series of studies from the citadel of German medicine - Heidelberg, exploring encouraging early results linking consumption of vitamin K2 and lower advanced prostate cancer, specifically, a lower risk of dying. In fact, K2 seemed generally to lower cancer risk a bit, but with a pronounced impact on prostate and lung cancer.
K2 comes from meat and cheese
, and the study results suggested that cheese was superior to meat as source. (That's good because red meat (and pork) have a lot of arachidonic acid and saturated fat that are not good for us prostate cancer patients.) Interestingly, vitamin K1 - found in leavy green vegetables and some vegetable oils - was not found helpful for coping with prostate cancer.
The researchers note that their study was not designed to show cause and effect, opening the possibility that some other aspect of cheese was responsible. However, in addition to the food-diary data in this study, the same team has published papers on their lab work and in-depth analysis of patients in the study that suggests K2 as the key agent.
This work is available via a search of www.pubmed.gov, a site we can use on the board because it is Government sponsored. The search string I used (without the quotation marks) was: " linseisen j [au] AND prostate cancer AND vitamin K2 ", and I got three hits.
Considering all three abstracts, it looks to me like the benefit in avoiding advance and high grade cancer is thought most likely to fall in the range from 20% to 40%.
Two of the three studies have free links, but I have not read the complete papers, only the abstracts. Some of this is pretty technical.
Until the last month I have consumed virtually no cheese since early in 2000, shortly after my diagnosis, when I learned about the possible link between dairy food and prostate cancer. I am now eating a little cheese, but I would be delighted to again make this great food part of my diet. I intend to be conservative about this because the nutritional regimen I've been following is probably one of the key reasons I've been so successful in coping with a challenging case. I'm hoping some of our leading experts on nutrition and prostate cancer will address this.
Three of the newsletters/magazines I receive have recently highlighted this possible link between K2 and a lower risk of advanced or lethal prostate cancer. Vitamin K2 appears to be a hot item, something not previously recognized. It should also be possible to rework a number of older studies to see if their data also suggest a K2 link with a lower risk from advanced prostate cancer. This could develop fast!