Treating Advanced Prostate Cancer with Diet: Part 1
"Treating Advanced Prostate
Cancer with Diet: Part 1" Dr. Dean Ornish showed that a plant-
based diet and lifestyle program could apparently reverse the
progression of prostate cancer by making men’s bloodstream nearly 8 times
better at suppressing cancer cell growth, but this was for early stage, localized,
watch-and-wait prostate cancer. What about for more advanced
stage life-threatening disease? There had been sporadic case reports
in the literature suggestive of benefit. A man, for example, with
extensive metastatic disease, given maybe three years to live,
goes on a strict plant-based diet. Four years later, it appears
the cancer has disappeared.
Six years in, he gets a little cocky
and backslides a little bit on the diet. Cancer comes raging
back and he dies. But, that could have been
a total coincidence. That’s the problem with case reports,
which are just kind of glorified anecdotes— you have no idea how representative the
outcome is unless it’s formally studied. But throughout the 20th century, all we had
were these kinds of case reports… until 2001. So, we had this preliminary evidence
based on all the case reports that prostate cancer may be sensitive
to diet even after it metastasizes, may prolong survival
and even cause remission of bone metastases in men
with advanced disease. So, researchers decided to put it to
the test, 4-month intervention.
They figured too much saturated fat,
too little fiber, and too much meat may be the biggest players in
tumor promotion and progression. So, they put people on a
whole food plant-based diet of whole grains, beans,
seeds, and fruit. Figuring this would be quite the
departure from their regular diet, they included a stress reduction component
in hopes of improving dietary compliance. Okay so, who were
these ten men? They all didn’t just
have prostate cancer; they all had underwent a radical
prostatectomy to remove their primary tumor, and then subsequently
had increasing PSA levels, indicative of probable
metastatic disease. PSA stands for prostate-specific antigen;
it’s only made by prostate cells, and they just had their
entire prostates removed. So the level
should be zero. The fact that they not
only still had some PSA, but that it was rising suggests
that the surgery failed, and the cancer had spread
and was making a comeback.
Here’s where they started
out before the study began. This is a graph of the speed at
which each of their PSAs was going up. So, if after 4 months of eating healthy,
the graph looked like this, it would mean the
diet had no effect. The cancer would presumably still be powering
away and spreading just as fast as before. Instead, this happened. In two men, it looks like the cancer
accelerated, grew even faster, but in the other 8 men, the
intervention appeared to work, apparently slowing
down cancer growth, and in three it didn’t
just slow or stop, but appeared to
reverse and shrink. Why the different
responses? Well, in the Ornish study,
the more people complied with the diet and lifestyle
recommendations, the better they did.
Dietary changes only work
if you actually do them. Just because you tell people to start
eating a whole food plant-based diet, doesn’t mean patients
actually do it. One can use fiber intake as a
proxy for dietary compliance, since all whole plant
foods have fiber, and Ornish’s patients about doubled
their fiber intake from 31 to 59. How did this group do? They started out even worse,
averaging 14 grams a day, and only made it up
to 19 grams a day. That’s not a whole
food plant-based diet— that doesn’t even make it up to
the recommended minimum daily intake. If you look closely, only 4 men
increased their fiber intake at all. So maybe that may explain
the different responses. Like, how did
patient 2 do? The man whose fiber improved the
most had the best PSA result, and the man whose fiber intake dropped
the most had the worst PSA result.
Here’s the graph. And indeed, it appears the
more change they made to their diet, the
better their results. The researchers concluded that
a plant-based diet delivered in the context of stress management
may slow the rate of tumor progression, and unlike other treatments, may give
patients some control over their disease. And, as Ornish
pointed out, “the only side effects
are beneficial ones.”.
