This month I want to concentrate on prostate cancer (PC) and nutrition. I wrote a blog on this subject, previously (see Nutrition - Prostate cancer).This would be worth reading. It focuses on some of the reasons given for the rise in prostate cancer and looks specifically at food sources of the phytonutrients Lycopene, Selenium, Vitamin E, Indoles, Curcumin, polyphenols and Saw Palmetto all of which have been shown to be supportive for those with PC. Although it was written some time ago the information is still current and my latest research does not unearth anything new.
So, with this in mind I want to add to the previous blog and use the blog that I am writing now to enlarge on some of the detail and give more information that has been shown to support those with prostate cancer.
As we know the role of diet and nutrition in the development of this and other cancers has received increasing attention. The basic outline for a healthy diet was written on July 2017. This is based on the Mediterranean style of eating consisting largely of vegetables, fruits, pulses, nuts, grains, good oils, chicken and seafood and whole grains.
A systematic review and meta-analysis of observational studies of the Mediterranean diet found that the highest adherence to this diet was significantly associated with a lower risk of mortality from prostate cancer as well as several other cancers. This information seems very straight forward and other sources would support these recommendations.
Prostate cancer is one of the most rapidly increasing types of cancer and its causes and nutritional approach are very similar to breast cancer.
I want to now look at some of the debated topics linked to prostate cancer and nutrition.
- Keeping to a healthy Body Mass Index; This seems to be one of the strongest factors associated with PC. Numerous studies that I have read have shown that overweight men have a greater risk of developing more aggressive PC. It is worth noting that our fat is biologically active and stores excess hormones including oestrogen in both men and women. Oestrogen (oestradiol) has been shown to be responsible for turning safe testosterone into DHT which is an extremely aggressive cancer-causing agent. Men make more oestrogen these days, largely through poor eating habits (too much fat) and being overweight (fat again). So, you can see the lower the body fat the less oestrogen is stored and released into the body. Many people do not realize that there are several different types of oestrogen and oestradiol is one of the more aggressive one of the group. There are many external factors that also affect the levels of oestrogen stored in our fat. Oestrogen can be absorbed from animal fat, recycled drinking water, and some toiletries, pesticides and herbicides.
- Meat consumption should be kept down; There are many epidemiologic studies that have suggested a correlation between red meat consumption and PC. Reports indicate that men with the highest meat consumption were 2.64 times as likely to develop PC as men with the lowest intake. The association between meat consumption and PC is particularly strong with meats that are cooked at high temperatures and charred, including processed meats like sausages, bacon and hot dogs. Longer cooking times, barbecuing and frying such meats produce larger amounts of compounds that are carcinogenic
- Choosing the right fats. This is an important issue and is cited in many research studies. It is important to choose the right types of fats to have in the diet. It appears that the highest prevalence of PC was in men with the highest intake of saturated fat found in animal derived foods. Several mechanisms have been suggested to explain this. They involve unbound insulin growth-like factor, hormone metabolism and free radical damage that comes from eating damaged fats created through the cooking process. On the other hand, a low fat or right fat diet shows less unbound insulin-growth like factor, testosterone and oestradiol (strong oestrogen). The right fats particularly those rich in omega 3 fatty acids seem to be beneficial. I have written about this in the first blog on prostate cancer as in the past it has been a controversial subject. Omega 3 is found in oily types of fish, flax seeds, pumpkin seeds and their oils and walnuts.
- Think about dairy foods. There is a great deal of research suggesting that dairy foods promote prostate cell proliferation. Epidemiologic studies have shown a direct correlation between dairy foods and an increased risk of PC. This may be due to the presence of growth factors in the milk which can cause rapid division of cells and disrupt normal hormone balance by increasing oestrogen levels. The high calcium has also been cited as reducing vitamin D levels. Vitamin D has been shown to be protective. Plant based milks are readily available and their use may be worth considering.
- Cruciferous vegetables. There are many studies implying that the cruciferous vegetables are very beneficial because they contain high levels of antioxidant enzymes and sulforaphanes which have been shown to help induce apoptosis (cell death) and indole-3-carbinol which has been shown to convert the strong oestrogen (oestradiol) into a weaker one called oestrone. The weaker oestrogen does not convert into DHT (the very strong cancer causing agent). Cruciferous vegetables are of course broccoli, cauliflower, cabbages, Brussels sprouts, bok choy and kale. Although reports about their anti-cancer benefits are mixed it is worth noting that these types of vegetables are extremely healthy, fat free and the cornerstone of a successful weight loss programme along with all other vegetables.
- Pomi T. I cannot talk about PC without talking about Pomi T. This is a food form supplement developed by Professor Robert Thomas, an oncologist who works at Bedford and Cambridge hospitals. He spent time researching polyphenols in food and their positive impact on cancer. He used PC patients as his study group and found many positive benefits from 4 polyphenols in particular, namely, Broccoli, Pomegranate, green tea and curcumin. These 4 are in the supplement PomiT.
It is worth remembering that when we use mostly observational studies that we must also take into account all the other variables that may influence outcome, for example total calorie intake, family history, physical activity levels, alcohol consumption and general diets of people being studied. All of these may influence the outcomes. However, the sections that I have written about above, mostly from observational studies, are researched and reported on so often that the messages that they portray seem to be very clear and worth adhering too if possible.
I would recommend reading the first blog on PC, as that one and this one that I have written go together.
Blog originally written by Caroline, Sept 2017 - links checked April 2020