Understanding Prostate Cancer
A New Diet to Quash Inflammation May Benefit Men’s Prostate Health
The anti-inflammatory diet is trending; could it help prevent prostate cancer or enhance survivorship? Recent evidence suggests: yes
June 20, 2013 -- An unresolved question in prostate cancer research goes like this: Does microscopic inflammation of prostate cells lend to the eventual development of prostate cancer? And if so, could a diet that aims to reduce cellular inflammation help men avoid this disease? If this seems far-fetched it’s worth remembering that inflammation is implicated in a number of diseases such as heart disease, arthritis, and Alzheimer’s, not to mention aging in general.
As cells in the prostate transition from normal to cancerous, they may enter an in-between state known as prostatic intraepithelial neoplasia or PIN for short. Not all PIN cells in the prostate will become cancerous, but it is thought that many of these cells are precursors to cancerous prostate cells, and men found to have PIN cells on biopsy are often followed closely to be sure cancer does not arise. More recently, Dr. Angelo De Marzo of Johns Hopkins Medicine discovered what is thought to be a prelude to PIN. He discovered that even before prostate cells enter a PIN state, they exhibit significant signs of inflammation.
Dr. De Marzo dubbed these cells PIA cells for proliferative inflammatory atrophy. Under the microscope PIA cells look shrunken and inflamed. This discovery has led researchers to speculate that inflammation may be a very early push factor inducing healthy prostate epithelial cells onto a cancer trajectory.
The connection between inflammation, obesity and prostate cancer
While it remains theory that inflammation may be an essential link in the development of prostate cancer, the evidence is strong enough to warrant serious attention. Studies are ongoing to get more definitive answers on the inflammation/prostate cancer link, but there is already evidence that obesity increases the risk of developing prostate cancer and that obesity increases inflammation throughout the body. Men with excess inflammation of their prostate gland are at greater risk of having high-grade, aggressive prostate tumors. Furthermore obesity increases the risk of death from prostate cancer.
Enter the anti-inflammatory diet
Inflamed cells and tissue are not just implicated in prostate cancer development and progression; chronic inflammation is estimated to play a causative role in as many as 20 percent of human cancers. Given this cumulative data, it’s no wonder that the anti-inflammatory diet is trending in Hollywood (Details magazine recently reported actor Matthew Fox anti-inflammed his diet to get screen-ready for the movie World War Z) and across the country. And, because the anti-inflammatory diet is likely to reduce body weight, on the whole it may well be a win-win for men—a trimmer, fitter body, not all angry and red and swollen on the inside, is likely to make guys feel good both inside and out. And it’s hard to underestimate the positive effects a man in good shape and fair spirits can have on the ladies, or their partners.
While there is no exact definition of the anti-inflammatory diet, it’s similar to the Mediterranean diet. Dr. Andrew Weil has developed an anti-inflammatory food pyramid that gives heavy weight to fruits and veggies and also includes “unlimited amounts” of herbs and spices such as ginger, cinnamon and garlic. And there’s a strong emphasis on tea—he recommends two to four cups a day of white, green or oolong—and eating loads of healthy fats such as those found in walnuts and avocados.
The latter syncs well with a study published online this month in JAMA Internal Medicine that found that simply adding one tablespoon of oil-based salad dressing a day to a man’s diet lowered his risk of developing lethal prostate cancer by 29 percent and his risk of death from any cause by 13 percent. A one-ounce serving of nuts per day translated into an 18 percent lower risk of lethal prostate cancer and an 11 percent lower risk of death.
The study followed 4,577 men with non-metastatic prostate cancer enrolled in the Health Professionals Follow-Up Study. Every four years, men were questioned regarding their eating habits. The researchers found an inverse relationship between risk of death from prostate cancer and the levels of “healthy” fats consumed. For example, men who consumed the highest amount of vegetable fats had the lowest risk of developing metastatic prostate cancer or dying from the disease. By comparison, men who ate large amounts of animal fats and trans fats (often found in processed foods or commercial baked goods and fried foods) had the highest risk of death during the study period.
“Our main conclusion,” says lead study author Dr. Erin Richman, a nutritional epidemiologist working in cancer research at the University of California San Francisco’s Department of Epidemiology and Biostatistics, “is that men with prostate cancer should follow a diet rich in unsaturated fats and nuts to decrease their risk of death.”
In the Complete Idiot’s Guide to the Anti-Inflammatory Diet, co-authored by Dr. Christopher Cannon, associate professor of medicine and Harvard Medical School, there are seven guiding principles to an anti-inflam diet:
- Eat a balanced variety of healthy foods
- Eat only unsaturated fats: e.g., fats in fish, nuts and vegetable oils--olive, canola or sunflower
- Eat one good source of omega-3 fatty acids every day: e.g., flaxseed, salmon, soybean oil
- Eat a lot of whole grains: e.g., whole wheat bread, quinoa, brown rice
- Eat healthy sources of protein: e.g., beans and lentils, tofu, cage-free eggs, Greek yogurt
- Eat load of fruits and vegetables –you know what those are!
- Ditch refined and processed foods as often as possible: e.g., donuts, white rice, white bread, etc.
In their book, the authors heap special scorn on trans fats, writing: “trans fats are the gang leaders when it comes to inflammation,” and point out that in the interest of public health officials have requested that local food suppliers eliminate trans fats from the fare they serve. (See anti-inflam diet principle number two! Also: The book serves up a variety recipes such as Greek spinach risotto, apricot bars, stuffed cabbage, and smoothies, all designed to anti-inflam you.)
One way to know if you’re getting trans fats unwittingly is to think of a trip to the supermarket as a reading and shopping expedition. Put on those spectacles and check labels closely, especially on products like cake mixes, cookies and crackers, pizza, margarine, and fried foods.
As for putting that serving of salmon in your shopping cart, it may be helpful to know some research has shown the fatty acids found in this fish may thwart cancer growth. For example, at the annual meeting of the American Association for Cancer research this spring, researchers from Fox Chase Cancer Center in Philadelphia presented data showing that omega-3 fatty acids inhibited breast cancer cell proliferation. They found that omega-3 fatty acids most strongly limited cell line growth (by up to 90 percent) in the most lethal type of breast cancer. And other research has shown that for men who have prostate cancer, omega-3 fatty acids may improve prognosis, although much more research needs to be done to verify those early findings.
However, as with most things in our diets, moderation seems to be the key. In a study published recently in the Journal of the National Cancer Institute (JNCI) that looked at blood levels of omega-3 fish oil-derived fatty acids in men, the researchers found that men with the highest levels of these fatty acids actually increased their risk of developing prostate cancer by 43%; their risk for developing aggressive prostate cancer increased by 71%. (To attain the highest levels of omega-3 fatty acids in the study, men would either have had to take fish oil supplements or eat 2 to 3 servings of fatty fish a week.) And remember, there are different forms of omega-3 fatty acids. It’s important to note that omega-3 fatty acids derived from vegetable oils or flaxseed did not increase prostate cancer risk in the study. First author of the JNCI study on fish oils and prostate cancer risk, Dr. Theodore M. Brasky of the Ohio State University Comprehensive Cancer Center, stresses, “This research does not address survival or prognosis for men already diagnosed with prostate cancer.”
Given this information, some experts, including Brasky, now recommend against men taking fish oil supplements, which are high in fish-derived omega-3 fatty acids, and to limit dietary intake of oily fish such as salmon, mackerel, or trout to no more than twice a week. As always talk with your doctor about individual risks and benefits to any dietary or supplement approach.
On the whole, says Richman, “the anti-inflammatory diet is an interesting approach and includes many foods that may have health benefits for men with prostate cancer.”
She also notes that, “High levels of inflammation in the body, as well as insulin resistance and oxidative stress, both of which often accompany chronic inflammation, may affect prostate cancer progression through several mechanisms,” said Richman. Such mechanisms include unchecked cell growth, failure of damaged or mutated cells to die off, and activation of molecular signaling pathways the can induce cancer cells to invade nearby tissue and also spread throughout the body. However, she also notes that further research into certain components of the anti-inflammatory diet, as well as the dietary pattern as a whole, is needed in order to assess how this diet might affect men with prostate cancer.
Prostate Cancer Foundation funding research to better understand connectivity between diet, inflammation, lifestyle and prostate cancer
Prostate Cancer Foundation Young Investigator Dr. Stacey Kenfield, who is a co-author on the JAMA Internal Medicine study and the first author of research presented at this year’s annual meeting of the American Association of Cancer Research in Washington, DC on the association between diet and prostate cancer, is researching how individual health behaviors, such as diet or exercise, make a difference in survival rates or other outcomes for men with prostate cancer. Kenfield moved from Harvard University to UCSF last year where she is continuing her work on a predictive model for prostate cancer recurrence and death in men based upon the lifestyle choices they make. This will further arm physicians with hard numbers and percentages as they counsel men with prostate cancer on the added benefits, after accounting for clinical factors related to diagnosis, of sticking to a particular diet or how often they must exercise to realize benefits in terms of survival.
And not only is Kenfield helping to determine how healthy diets or exercise can affect men’s risk of dying from prostate cancer, she is developing an online program that men with prostate cancer can use to enhance healthful lifestyles. “There are a number of dietary and lifestyle factors that men can adopt to reduce their risk of death from prostate cancer,” said Kenfield. “We hope the program will encourage men to make these healthy choices.”
The Prostate Cancer Foundation provided funding for the JAMA Internal Medicine study and is funding several investigators researching the connection between lifestyle and prostate cancer survivorship. For example, PCF-Young Investigator Dr. Karen Sfanos of Johns Hopkins Medicine is studying if particular foods cause chronic inflammation in men’s bodies. And Dr. David Finley of the University of California, Los Angeles is looking into the links between body fat, inflammation and prostate cancer risk, and if where fat is stored in a man’s body may raise his risk of lethal disease or increase inflammation in the prostate gland.
Chronic inflammation may well be a culprit in prostate cancer mortality rates. While the jury is still out on the prostate-health benefits of the anti-inflammatory diet, the good news is that eating a diet that can save you from death by heart attack or stroke looks similar to a diet that may reduce your likelihood of dying from prostate cancer. Stay tuned for more research on the link between diet and prostate cancer survival.
Last Updated July 16, 2013