Prostate cancer is one of the leading causes of death for men in New Zealand. Around nine people a day are diagnosed. Yet prostate health (like most men’s health topics) is not widely talked about when compared to women’s health topics.
There has certainly been more awareness over the past five years with high-profile campaigns, but many men are still avoiding the doctor’s office for their general checkup and the like, and many are living with prostate problems — either thinking they are just an inevitable part of ageing (they are not) or a little afraid of what they might find out if they get their checkup.
Problems with the prostate extend beyond cancer and have been linked to increased risk of other chronic conditions, such as cardiovascular disease. As one of the potential mechanisms by which benign prostatic hyperplasia (BPH) occurs is through inflammatory pathways, it’s not surprising that there are links here with other conditions of inflammation.
Most problems with the prostate are not cancerous; benign prostate enlargement is a common condition in men as they age, as the glands can swell and block the flow of urine. The symptoms are varied depending on the individual, but some of the common ones include:
- difficulty initiating urination due to BPH pressure on the urethra, which requires more urine to build up to enable to push-through
- intermittent flow
- weak flow (at the urinal for what seems like hours!)
- "dribbling" and urinary urgency as the nerves around your bladder may not be able to send the correct signals to your brain (also known as spastic bladder)
- inability to sleep as you feel like you "need to go", when in fact there is very little fluid there to be voided
- inability to properly empty the last bit, and suffering from muscle injury to pelvic floor, haemorrhoids or even fainting mid-or post urination
- increased risk of urinary tract infections due to thriving bacteria and bladder stones, or impaired kidney health due to build-up of urine in the bladder.
It’s quite a list and though not confirmation of a serious diagnosis, men should make that trip to their doctor’s office if they experience any of the above.
What role does diet play?
Most of the research looking at prostate health has reported on similar elements of the diet or dietary patterns for men with prostate cancer, and from here suggestions are made as to what is protective and what may increase risk. As with any nutrition research, we are limited by the quality of information provided by dietary surveys — despite this, we can make general observations about dietary factors and their role in prostate problems.
Red and processed meat are often the first thing to be mentioned when considering cancer risk — and that science is muddied by a number of factors. First, processed meat is often grouped with fresh red meat when people are asked about consumption, and there is quite a difference between, say, an eye fillet steak and a pre-cooked sausage.
Furthermore, the types of foods people consume with aforementioned processed meat (think: burger, fries, and soft drink) carry with them a caloric load and are highly processed — which we now understand as increasing overall cancer risk. Though statisticians use methods to try to remove this relationship, many people argue (and I agree) that you can't adjust this away.
The type of lifestyles led by many heavy meat consumers are also less than optimal: lower levels of physical activity, higher amounts of alcohol, more likely to smoke and lower fruit and vegetable consumption. Combined, these are a perfect storm for any chronic disease risk — cancer included.
Finally, the research that supports a relationship between cancer and red meat consumption often comes out of North America where the agricultural practices (how cattle are fed, raised, cared for and killed) are quite different from here in New Zealand. So is red meat consumption associated with increased prostate cancer risk?
Despite all the considerations I’ve listed above, a recent overview of studies has dispelled that myth, but did show a weak (but significant) association with processed meat consumption.
What about protein intake in general (not just from meat, but eggs, nuts, fish, dairy)? Unclear at this stage, but the trend appears to be towards an adequate protein intake rather than a high protein intake.
So, what about fat intake?
Again, a vilified nutrient in many areas related to nutritionand health; a recent overview of literature found there has been no conclusive evidence to suggest that overall fat intake, saturated fat intake or polyunsaturated fat, influences prostate cancer risk.
The essential fatty acids (omega 3s —fatty fish, grass-fed meat) and optimal ratio between omega 6 and omega 3 fats (the former being a prominent fat source found in processed foods and seed oils, margarines) could well be important for reducing inflammation and improving outcomes associated with prostate cancer.
Carbohydrate intake is hypothesised to influence risk, due to its ability to raise insulin, which is a growth factor for cancers. Though studies conducted using metformin are showing potentially promising effects at reducing prostate cancer markers, both in laboratory based and clinical trials (metformin is an insulin-lowering drug used most frequently for people with type 2 diabetes, with little side effects), there are, to date, no randomised controlled trials that conclusively show this as a preventive or adjunct therapy for men with prostate cancer.
Digging a little deeper into micronutrients, optimal blood levels of selenium, vitamin D, vitamin K2 and folate are all related to a reduced risk of prostate cancer.
Turning our attention to actual foods
We know vegetables are awesome in general and though the number of studies are small, they suggest allium vegetable intake (think onions, garlic and leeks) may be protective against prostate cancer, with population studies showing a higher intake of fruit and vegetables is protective against cancer risk.
Cooked tomatoes are known for their antioxidant content, and small trials show lycopene itself may slow prostate cancer progression, though the jury is out on the actual fruit.
The antioxidants in coffee (caffeinated or otherwise) may also reduce risk for regular consumers compared to those never consuming, though an interesting point to consider with this (and any caffeine-related research): people who metabolise caffeine well will generally feel good drinking it and may have a higher intake. In addition, certain genes that help you metabolise caffeine are also responsible for metabolising environmental toxins. This does suggest a genetic link to the health effects of caffeine which are yet to be explored.
And alcohol? Unsurprisingly, heavy drinkers may have an increased risk of developing prostate cancer, though the research is a little muddied.
An ever-expanding field in nutrition research is the presence of phytochemicals in food and their relationshipto health. Digging a little deeper in the weeds and focusing specifically on prostate cancer, green tea extract was found to slow tumour growth in a small proof-of-principle trial with 60 men.
Daily supplementation of 600mg green tea catechin extract reduced prostate cancer incidence by 90%(3% versus 30% in the placebo group). When green tea extract was combined with Co-Q 10 (an antioxidant found in animal foods), cancer cells were found to respond better to chemotherapy treatment. Curcumin (one of the active components of turmeric) showed similar properties in the laboratory setting.
Overall, what does this mean for you and your risk?
Are you at increased risk if you don’t like coffee or are allergic to tomatoes? Dietary pattern is key. You could slug back coffee, enjoy tomatoes, pop a green tea and essential fatty acid supplement but if you have a typical Western diet pattern (with high intakes of processed meats, fried fish, chips, white bread, and so on) these band aid steps to improve health will not offset the risk involved of eating a junk diet.
However, if we follow the lead from the research and include plenty of vegetables, some fruit, enjoy fatty fish and have a lower intake of processed foods, plus enjoy a green tea regularly, then you’re likely on the right path.
Indeed, I know of many people who switch to a dietary pattern such as this and have reduced their BPH.
Finally, supplementation is individual and ideally worked on with a health professional to determine that you're not doing more harm than good. In the spirit of men's health month, it's a perfect opportunity for you to make changes if need be.
Read more about cooking for prostate health here
Through her subscription service of meal plans and nutritional support, nutritionist Mikki Williden helps people manage their diets in an interesting way, at a low cost. Find out more at mikkiwilliden.com