As of 2011, only three research articles, according to the National Institutes of Health, have focused on the effects that dietary pumpkin seeds have on prostate health. None of the articles, however, focuses on the role of pumpkin seeds on prostate cancer. They focus on the effects of pumpkin seed on benign prostatic hyperplasia. BPH, a disorder that most men will suffer given a long enough lifespan, occurs when the prostate begins to enlarge. While BPH is increased growth of the prostate, it is not the same as prostate cancer. Do not use pumpkin seeds to treat prostate cancer. Consult your doctor.
As mentioned in two separate articles published in 2006 editions of "Urologia Internationalis" and the "Journal of Medicinal Food," Dr. Yuh-Shyan Tsai and M. Gossell-Williams, respectively, observed that administration of pumpkin seed oil to rats that were chemically or hormonally induced to undergo increased hyperplasia or excessive prostate growth, significantly decreased the observed prostate size in the rats.
Clinical BPH treatment
According to the 2009 issue of "Nutrition Research and Practice", Dr. Heeok Hong observed that a 12-month clinical administration of pumpkin seed oil to male patients decreased the international prostate symptom score, an overall indication of prostate disease symptoms. Lower the score, and the symptoms get better. Although prostate volume did not decrease significantly, pumpkin seed oil improved quality of life, and increased urinary flow in patients.
Mechanism of Action
According to the 2006 issues of "Urologia Internationalis" and the "Journal of Medicinal Food," Dr. Yuh-Shyan Tsai and M. Gossell-Williams indicate that pumpkin seed oil functions in part to regulate BPH, by inhibiting the prostate enzyme 5-alpha reductase. This protein, in the prostate, converts testosterone into the dihydrotestosterone, or DHT. While this is a normal process necessary for male development and reproduction, excessive DHT can act as a potent growth inducer of prostate cells. Too much DHT can lead to BPH.
Although BPH is a different disease than prostate cancer, some of the same processes regulate both disorders. For example, according to the 2007 issue of "Prostate," Dr. Teri Wadsworth shows that excessive DHT can also play an important role in prostate cancer growth and progression. The necessary experiments still need to be performed, but this data indicates that pumpkin seed oil might have a limited effect on prostate cancer.