Ask the Doctor:
Q: Is Pumpkin Seed Oil or Extract good for men trying to prevent prostate cancer?
A: Okay so the real question here is, given the confusing, contradictory claims about supplements, and the money we need to spend on essential supplements, “Is pumpkin seed the best “bang for our buck”?
It’s worth starting with how we evaluate data in what we call an “evidence-based approach” at Associates of Integrative Medicine.
We do not use anecdotal or preclinical data when we are treating you.
Anecdotal data is:
● “First Nations people used pumpkin seeds to treat urinary problems and intestinal issues which led the United States Pharmacopoeia to list pumpkin seeds as an official medicine for parasite elimination from 1863 to 1936.”
● “In traditional Chinese medicine, pumpkin seeds are used as an anti-parasitic and to treat high blood pressure.”
● “Mexican herbalists have used pumpkin for metabolic control.”
These things are historically true. Anecdotal data is powerful, moving, and suggestive. Meaning, it gives us a ton of clues as to how a plant can be used.
Preclinical data is:
“Researchers at the University of Nottingham, England, applied pumpkin seed oil to prostate and breast cancer cells in a controlled setting and found a 20-70% decrease in the rate of cell growth.
Authors conclude that the cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds as a treatment of benign prostate hyperplasia and potential adjunct for treatment of prostate cancer.”
Preclinical data is exciting and gives well-funded groups an incentive to try the plant on people.
But neither anecdotal or preclinical data are strong enough for us to use it in treating you or making supplement recommendations.
When WE look at data at AIM, we look at clinical trials in humans. And we look to see what factors contributed to the conclusions, were nutrition, stress, lifestyle, sleep and other issues taken into account. And further, we look to see if that data is reproduced consistently over time.
On the other hand, it’s also not true when your oncologist tells you that there are no natural therapies with human data! What IS true is you have to know HOW to look….but enough on data.
Let’s get to some nitty gritty on prostate cancer.
The prostate is a gland that sits like a cushion between the bladder and the penis. The urethra, which carries urine from the bladder out, travels through the prostate and is also the tube by which we transport semen out of the penis.
The prostate’s job is to produce prostatic fluid, which is a nourishing and protecting liquid that suspends sperm (which are produced in the testicles) and supports them in movement. During ejaculation, the prostate contracts and the prostatic fluid joins the sperm to make what we call semen (sperm + prostatic fluid).
As we age, the prostate can become enlarged because of several conditions. The three most common prostate problems are
1. benign prostatic hypertrophy (BPH);
2. prostatitis, an inflammation of the prostate sometimes caused by an infection;
3. cancer
Prostate cancer is the second most common cancer in men worldwide with 1.2 million new cases. It’s analogous to breast cancer in women, as the prostate, like the breast, is a glandular tissue that relies on hormonal regulation, is partnered to reproductive development and is vulnerable to environmental and dietary stress.
As such, both breast and prostate cancer are typically diseases of aging. If we autopsy 100 men over age 90, we will find prostate cancer in almost all of these men.
Heads up, guys! There is a ton of money devoted to preventing and treating breast cancer because women are well organized and vocal behind their collective health. Men need to model themselves here and really work towards opening themselves up to talking about their intimate health. Get vocal! Like early stage breast, if caught early, prostate cancer is a curable disease.
Your life and that of your brothers is worth fighting for.
I know, I know, what about pumpkin?! I promise I will get there.
Sigh. It’s expensive to see us, and there is so much that goes into how we formulate an individualized approach to treatment, that we need to use every minute to design the highest performance strategy unique to YOUR circumstances, so we rarely get a chance to teach to all these pearls that we think are necessary to live your best life.
Back to the Great Pumpkin Debate. For those of you impatient for the answer, pumpkin seed has NO clinical data that it is effective in the treatment of prostate cancer.
But there is MORE to the story which means there are more sophisticated ways to look at the data.
To know where to look, a good doctor needs to understand what pumpkin seed is. Pumpkin seed is a phytosterol. Phytosterols are plant-based compounds found in:
Pumpkin seeds > soy beans > green peas > sesame > kidney beans > pistachio nuts > lentils > cashews > oranges > almonds > olive oil > banana > brussels sprouts.
Phytosterols are like kryptonite to cholesterol. When we consume them, they interfere with the intestinal absorption of cholesterol in our diet and they also cause the body to increase the amount of cholesterol we dump in our poop.
Clinical data DOES conclusively show us that daily consumption of phytosterols from food can significantly lower our serum LDL (low density lipoprotein). An average phytosterol intake of 2 g/day lowers LDL by up to 10%.
Why does this matter? Right now, older drugs are being repurposed and used in an experimental way to prevent prostate cancer. One of these is a class of drugs called statins. Epidemiologic findings suggest that statins use may have a beneficial effect on the risk of prostate cancer progression and death. This gives us some indication that the root cause of prostate disease may have something to do with inflammation in the microenvironment due to how we use fat and sugar.
So can we conclude a supplement high in at least phytosterols in our clinic is at least protective by virtue of lowering LDL and perhaps getting at the root cause of prostate disease? Perhaps. But we would want that same supplement to be high as well in phytoestrogens.
What are these?
Phytoestrogens are naturally occurring plant compounds that are hormone modulators. Genistein and daidzein, the predominant phytoestrogens in human nutrition, are derived mainly from soybeans, lentils and other legumes.
Phytoestrogens may reduce prostate cancer risk by favorably altering the hormonal milieu or by inhibition of 5-alpha reductase (5-AR), which decreases concentrations of the more prostate-active androgen dihydrotestosterone (DHT). It’s this potent DHT that causes accelerated growth of prostate cells and may result in more cell errors (cancer).
The higher intake of soy products among Asian men has been hypothesized to be one reason for the lower incidence of prostate cancer among these men. In humans, most of the case-control studies have shown a modest protective benefit of soy on prostate cancer risk.
Okay so we are making some progress here!
We have narrowed our recommendation to supplements high in phytosterols and phytoestrogens AND at the same time we have expanded our investigation to look at nutritional strategies that may modify cholesterol and hormonal health.
How does THIS data look? Are nutritional strategies protective? Conclusively YES!
A diet high in animal fat may be an important factor in the development of prostate cancer. In particular, intake of large amounts of alpha-linolenic acid and low amounts of linoleic acid appear to be associated with increased risk; this combination is common in red meat and some dairy products. High intake of cruciferous vegetables (particularly broccoli and cauliflower) was associated with a significantly lower risk of extra-prostatic tumors. More recently, an analysis of a prospective cohort of 51,529 men from the Health Professionals Follow-Up Study has suggested that dietary intake of lycopene (found in cooked tomatoes) is associated with a lower incidence of prostate cancer and a decreased risk of lethal prostate cancer.
Okay, so now we know we need to look at a combination supplement that contains plant sterols and phytoestrogens and partner it with strategies that help our guys shift towards a plant based diet high in beans and legumes.
But can we pin pumpkin seed specifically here?
Knowing that breast and prostate are analogous and there is poorly funded and not readily available data on prostate and phytosterols, at AIM, we would expand our search to include breast.
A series case control studies in Uruguay found that dietary phytosterol intakes were lower in people diagnosed with stomach, lung, or breast cancer than in cancer-free control groups. Case-control studies in the US found that women diagnosed with breast or uterine cancer had lower dietary phytosterol intakes than women who did not have cancer.
Although higher intakes of plant foods containing phytosterols may be associated with lower cancer risk, it is not clear whether potential anticancer health benefits can be attributed to phytosterols or to other factors in eating plant foods (for example, we cannot account for vitamins, minerals, fiber, spiritual associations with avoiding animal fat).
So let’s back it up a bit, if the conclusions are so difficult to draw, what led researchers to look at phytosterols in the first place?
Well, we found that the investigation was based on robust animal data that looked at a type of phytosterol that inhibits prostate cancer. That phytosterol is sitosterol. So now we have only one more question: Does pumpkin seed contain high amounts of sitosterol?
Moderate amounts. Avocados contain much more. All nuts and seeds, oranges, beets and brussels sprouts are excellent choices. But avocados exceed every other choice in this category. If you eat one-half of an avocado, or about 2/3 cup of cubed avocado, you’ll consume 76 milligrams of beta-sitosterol, compared to 13 mg in a similar portion of pumpkin seeds.
A lot of men’s health blogs like Dr. Michael Murray, Livestrong, Life Extension, and urology blogs, discuss the content of zinc in pumpkin seed as being protective but in fact, the clinical data on zinc (supplementation) is mixed. Some studies show zinc as protective. Some show supplemental zinc as contributing to higher grade more aggressive lesions at diagnosis.
Okay, I know you may be confused. Don’t be. I am going to give you the takeaway.
Supplementation is tricky, and to us, it cannot replace good nutrition.
Supplements can only do two things:
1. Augment nutrition
OR
2. In high doses, from a high quality source, with human data, be used as a therapeutic.
Pumpkin seeds are an EXCELLENT food choice. They play a minor role in prevention, but as a targeted supplement are not necessarily your best choice for fighting prostate cancer alone.
The most effective strategies involve understanding what causes prostate cells to:
1. Grow too fast, and
2. To make mistakes when they do grow
The following would be a good evidenced based and general primer for one of our guys who is on the younger side and is looking at prevention or risk reduction in survivorship.
