September is National Prostate Cancer Awareness Month and there’s no better time than now to talk about two nutrients that may possibly reduce your risk of developing this disease. Before we get to that, let’s review facts on prostate cancer.
Prostate cancer is the most common cancer diagnosed in American men other than skin cancer. Here are key statistics from the American Cancer Society on prostate cancer for the year 2015:
- About 220,800 new cases will be diagnosed.
- About 27,540 deaths will occur.
- About 1 in 7 men will be diagnosed with it during their lifetime.
- It mainly occurs in older men with the average age at the time of diagnosis around 65.
- It is the second leading cause of cancer death in American men, only behind lung cancer.
- It is a serious disease, but most men do not die from it and the cure rate is high.
What is the prostate?
The prostate is a small gland about the size and shape of a walnut found in the male reproductive system. It lies just below the bladder in front of the rectum and is wrapped around the urethra which is a tube that carries urine and semen through the penis and out of the body. The purpose of the prostate gland is to make prostatic fluid that is mixed with sperm from the testicles along with secretions from the seminal vesicles during ejaculation.
Causes of an enlarged prostate
They say if a man lives long enough he will eventually develop an enlarged prostate and indeed as men age, prostate enlargement is certain to happen. As the gland of the prostate becomes bigger, it begins to press on the urethra causing urine and bladder issues. This condition is often called benign prostatic hyperplasia (BPH) meaning it is not cancerous nor does it raise the risk of prostate cancer. The actual cause of an enlarged prostate is unknown but most likely is due to aging and changes in the cells of the testicles. However, an enlarged prostate should be checked to make sure it is not cancerous.
Symptoms of an enlarged prostate
Not all men experience symptoms of an enlarged prostate, which is why it is important to have a regular prostate examination starting at age 40. If you have any symptoms of an enlarged prostate, it is important to have your doctor do a digital rectal exam and a blood test called a prostate-specific antigen (PSA) to screen for prostate cancer. Symptoms may include:
- Needing to urinate two or more times during the night
- Dribbling at the end of urinating
- Inability to urinate
- Incomplete emptying of the bladder
- Pain with urination or bloody urine
- Slowed or delayed start of the urinary stream
- Strong and sudden urge to urinate
- Weak urine stream
Nutrition’s role in helping to prevent prostate cancer
There are some things in a man’s life he cannot control such as aging or having a family history of prostate cancer. A lifestyle factor that is within his control is diet. Choosing to eat a healthy diet may reduce the occurrence of prostate cancer and possibly help curtail the progression of prostate cancer. Much research has been done to study the effects of diet on the development of prostate cancer looking at specific nutrients. Two nutrients that have gained attention over the years in possibly reducing the risk of prostate cancer is the mineral zinc and a phytochemical called lycopene.
Zinc – Zinc and the prostate have an interesting relationship. The highest concentrations of zinc are found in the soft tissue of the prostate along with high amounts of zinc found in prostatic fluid. In fact, zinc concentrations accumulate 10 to 15 times higher in the prostate than in any other body tissues. Also interesting is that zinc concentrations are much lower in the tissues of a malignant or cancerous prostate (about 10-25 percent) than that found in a healthy nonmalignant prostate. High concentrations of zinc appear to be necessary for keeping the prostate healthy by acting as a powerful tumor suppressor. The high levels of zinc appear to prevent cancer cell migration and invasion into other tissues.
“Zinc is an essential trace mineral, which means our body only needs a small amount of it (8 mg for women and 11 mg for adult men) to maintain good health,” said Dr. David Samadi, chairman of urology and chief of robotic surgery at Lenox Hill Hospital in New York City. “Did you know that a healthy amount of zinc in your diet has been linked to an improved immune system? It has a regenerative quality that helps with healing. This could also be the missing link for why it could help with keeping your prostate healthy.”
Men from age 19 and up require 11 mg of zinc a day. Most men do meet this requirement, but as they age their dietary habits can change and their intake may not be optimal. Epidemiological studies have shown that men with higher levels of zinc, whether from food sources or a supplement, have better protection from advanced prostate cancer. There was also a case control study that observed reduced prostate cancer risk with the usage of individual zinc supplements. However, other studies have shown that long-term and/or high dosage use of zinc supplements may increase the risk of prostate cancer.
A study conducted in Sweden, which has one of the highest prostate mortality rates in the world, accounting for 22 percent of cancer deaths in men, suggested that men diagnosed with a localized tumor or with early-stage prostate cancer and who consumed foods rich in zinc were 76 percent less likely to die of prostate cancer than men with a lower intake of zinc. This study only looked at the effect of dietary or food sources of zinc and not at zinc supplements.
Some dietary sources of zinc include the following:
- Beef steak – 3 oz. contains 4.9 mg
- Oysters – 3 oz. contains 67 mg
- Shrimp – 3 oz. contains 1.5 mg
- Pork chop – 3 oz. contains 2.8 mg
- Yogurt – 1 cup contains 2.2 mg
- Enriched cereal – 3/4 cup contains 15 mg
- Red kidney beans – 1/2 cup contains 2 mg
It is important to note that zinc from meat sources is absorbed better than zinc from vegetarian sources. Legumes and whole grains contain phytic acid which inhibits zinc bioavailability or absorption.
The best advice is to consult with your doctor about whether to supplement with zinc or not. The 2011 Swedish cohort study suggested that their results were not sufficient to recommend zinc supplements. In the meantime, consume rich food sources of zinc, particularly from animal sources, to have the best outcome.
Lycopene – This naturally occurring phytochemical belongs to a group of pigments known as carotenoids. It is responsible for giving many fruits and vegetables their red color such as watermelon, papaya, pink grapefruit, guava, apricots and above all tomatoes. Tomatoes and all tomato products contain high levels of lycopene and therefore account for 85 percent of lycopene in the American diet.
“Tomatoes contain lycopene – a powerful antioxidant that also gives tomatoes its rich red color. Lycopene may help lower prostate cancer risk, prevent prostate cancer or slow tumor growth in men who have prostate cancer because it works to fight inflammation,” Dr. Samadi said.
Many epidemiological studies have linked increased lycopene consumption with decreased prostate cancer risk. The reasons for this include:
- It enhances the antioxidant response of prostate cells.
- Inhibits proliferation of prostate cancer cells.
- Induces apoptosis which is a natural process that eliminates damaged, unneeded or dangerous cells from the body.
- Decreases the spread of prostate cancer cells.
There have been positive results from numerous studies focusing on tomato-based products containing lycopene. It has been shown that men who frequently consumed lycopene from tomatoes had an 11 percent reduced risk of prostate cancer and those who had a high intake of cooked tomato products had a 19 percent reduced risk. Because of results like this, it has spurred various health organizations to promote the benefits of eating more tomato products for prostate cancer prevention.
Processed tomato products include tomato paste, tomato puree and tomato sauce, all having richer concentrations and better absorption of lycopene than from whole, raw tomatoes.
“As an avid adopter of the Mediterranean diet myself, tomatoes are always a perfect food choice,” Dr. Samadi said. “Tomatoes release most of their lycopene when cooked or pureed. As they say, the more the merrier.”
As far as recommending lycopene supplements, there is limited research that has specifically analyzed the effects of supplementation. However, lycopene is an abundant phytochemical found naturally in relatively low cost foods with few side effects.
Men should keep in mind that increasing tomatoes and tomato based products is only one part of an overall health-promoting strategy that should also include maintaining a healthy weight, regular exercise, and eating lots of plant-based foods. Including at least two to three servings a week of tomatoes or tomato based products can be a part of the plan to help lower risk of prostate cancer. Here are some ways to increase your intake:
- Use canned tomatoes in chili, soups, stews, casseroles, or add to grain dishes such as rice, quinoa, couscous or bulger.
- Use tomato sauce or paste in Mexican dishes, spaghetti, lasagna, pizza, meatloaf, Swiss steak or other casseroles.
- Drink tomato juice.
- Serve fresh tomatoes in salads, salsas, dips, sandwiches, tacos and salads, or add cherry tomatoes to a vegetable platter or on kebobs.
Prostate cancer is not a given for all men. Even though most men will experience an enlarged prostate as they age, by educating yourself and understanding, steps you take to lessen the occurrence of prostate cancer will empower you to take charge of your health. Generally, prostate cancer grows slowly and when caught early is very treatable and the cure rate is high. By getting regular prostate exams, paying attention to and seeing your physician when you have symptoms associated with an enlarged prostate, along with following lifestyle factors such as eating foods with more zinc and lycopene, you will help yourself avoid a potentially deadly disease.
Cheryl Mussatto MS, RD, LD, is a registered dietitian and an adjunct professor at Allen Community College, Burlingame, and Butler County Community College, Council Grove; she teaches Basic Nutrition and Therapeutic Nutrition. She is also a certified health and wellness coach, and a consulting dietitian for the Cotton O’Neil Clinic in Osage City. She writes Eat Well to Be Well, a column about health and nutrition, and is a blog contributor for Dr. David Samadi at www.samadimd.com. Contact her at email@example.com, visit her website www.eatwell2bewellrd.com, or like “Eat Well 2 Be Well” on Facebook.