Transcript: Prostate Cancer Survival: The A/V Ratio
It is now 8 years since the famous Ornish study was published, suggesting that 12 months on a strictly plant-based diet could reverse the progression of prostate cancer.
Wait a second: How were they able to get a group of older men to go vegan for a year? They home delivered prepared meals to their door, figuring men are so lazy they'll just eat whatever is put in front of them.
But what about out in the real world? Realizing that you can't even get most men with cancer to eat a measly five servings of fruits and veggies, researchers settled on just trying to change their A to V ratio, the ratio of animal to vegetable proteins, and indeed were successful in cutting this ratio in half at least, from about 2 to 1 animal to plant to kinda half vegan, 1 to 1.
How'd they do? Looks like their cancer was slowed down. "The average PSA doubling time (an estimate of how fast the tumor may be doubling in size) in the half vegan group slowed from 21 months to 58 months. So the cancer kept growing, but with a part-time plant-based diet they were able to slow down the tumor's expansion. What Ornish got, though, was an apparent reversal in cancer growth, the PSA didn't just rise slower, it trended down, which could be an indication of tumor shrinkage. So the ideal A to V ratio may be closer to zero.
If there's just no way grampa's going vegan, and we just have half-measures, which might be the worst A and the best V? Eggs and poultry may be the worst, respectively doubling… and potentially quadrupling the risk of cancer progression in this study out of Harvard. Twice the risk eating less than a single egg a day, quadruple the risk eating less than a single serving of chicken or turkey.
And if you could only add one thing to your diet, cruciferous vegetables. Less than a single serving a day of either broccoli or Brussels sprouts, cabbage cauliflower or kale may cut the risk of cancer progression more than half, defined as the cancer coming back, spreading to the bone, or death.
This animal to plant ratio might be useful for cancer prevention as well. For example, in the largest study ever performed on diet and bladder cancer, just a 3% increase in the consumption of animal protein was associated with a 15% higher risk of bladder cancer, whereas a 2% increase in plant protein intake was associated with a 23% lower risk. Even little changes in our diets can have significant effects.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Ariel Levitsky.
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