Nutrition’s Role in Preventing Prostate Cancer

September is National Prostate Cancer Awareness Month and all men should become informed of the most common cancer diagnosed in American men other than skin cancer.  When men are educated on what they can do to lessen its occurrence, they become empowered to take charge of their health.   

Here are key statistics from the American Cancer Society on prostate cancer for the year 2016:

·         About 180,890 new cases will be diagnosed

·         About 26,120 deaths will occur

·         About 1 in 7 men will be diagnosed with it during their lifetime

·         Mainly occurs in older men with the average age at the time of diagnosis around 66

·         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

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, a tube carrying urine and semen through the penis out of the body. The prostate gland’s job 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.  As the gland of the prostate becomes bigger, it begins to press on the urethra causing urine and bladder issues.  This condition is 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.

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 to do 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

·         Incontinence

·         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 family history of prostate cancer or getting older. But one very important 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 have gained attention as to their role in reducing the risk of prostate cancer.  They are the mineral zinc and a phytochemical called lycopene.

1.      Zinc – Zinc and the prostate gland 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.  Concentrations of zinc are much lower in the tissues of a malignant or cancerous prostate (about 10-25%) than of what’s found in a healthy nonmalignant prostate.  High concentrations of zinc may be necessary for keeping the prostate healthy by acting as a powerful tumor suppression and may prevent cancer cell migration and invasion into other tissues. 

Men from age 19 and up require 11 mg of zinc a day.  Most men meet this requirement. However dietary habits can change with age and they may not be obtaining enough of it.  Epidemiological studies have shown 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 2011 cohort study conducted in Sweden, which has one of the highest prostate mortality rates in the world accounting for 22% of cancer deaths in men, suggested that men diagnosed with a localized tumor or with early-stage prostate cancer and who consumed food rich in zinc, were 76% 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 – ¾ cup contains 15 mg

·         Red kidney beans – ½ cup contains 2 mg

Zinc coming from meat sources is more readily bioavailable than zinc from vegetarian sources.  Legumes and whole grains contain phytic acid inhibiting zinc’s bioavailability. 

Consult with your doctor for their recommendation on 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.

2.      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% of lycopene in the American diet. 

 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

     Processed tomato products such as tomato paste, tomato puree and tomato sauce have richer

 Because of this, there is a strong correlation for increasing intake of tomato products and lowering prostate cancer.