Dr Greger just uploaded his newest talk, "Uprooting the Leading Causes of Death" which you can see here...
http://www.youtube.com/watch?v=30gEiweaAVQIt is an excellent 56 minute talk and one that everyone should see.
The talk was presented and recorded at the 2012 Vegetarian Summerfest and as he states, it focuses on
"studies published just over the last year in peer-reviewed scientific medical journals." And, as many of us may know, his personal goal, as stated at his websites is
"to present you with the results of the latest in nutrition and health research, presented in a way that is easy to understand."In watching the excellent presentation, there were several points raised that I would like to clarify, especially in light of the above interview as this thread was started because of that interview and the following quote from it...
"Yes, I have learned it's always best to seek out the primary sources to review them rather than rely on expert opinion. Too often we hear outdated information that is ego-based and supporting old theories that have been proposed. These include extremely low fat vegan diets, without nuts and seeds, or centering one's diet around white potatoes or white rice. This is just not the best science-based advice."So, again, lets take a closer look and at the primary sources...
During the segment on cancer, he raised the issue of "what if you put cancer on a vegan diet." He then begins to describe and discuss the research of the Pritikin Research Foundation on prostate cancer. (Yes, you know, that crazy outdated very low fat diet.)
The first study was actually done by both the Pritikin and Ornish groups, and, as he describes, was 8x better than the SAD in fighting prostate cancer cells (9% vs 70%)
Now, let's be clear on what these "vegan" diets actually consisted of.
From the actual paper...
"Experimental group patients were prescribed an intensive lifestyle program that included a vegan diet supplemented with soy (1 daily serving of tofu plus 58 gm of a fortified soy protein powdered beverage), fish oil (3 gm daily), vitamin E (400 IU daily), selenium (200 mcg daily) and vitamin C (2 gm daily), moderate aerobic exercise (walking 30 minutes 6 days weekly), stress management techniques (gentle yoga based stretching, breathing, meditation, imagery and progressive relaxation for a total of 60 minutes daily) and participation in a 1-hour support group once weekly to enhance adherence to the intervention.10 The diet was predominantly fruits, vegetables, whole grains (complex carbohydrates), legumes and soy products, low in simple carbohydrates and with approximately 10% of calories from fat.11"So, this was the very low fat, "near" vegan diet that was criticized above.
For the record, this was a diet that was a blend of the Pritikin & Ornish guidelines with no dairy (which both Ornish & Pritikin allow) or animal protein (which Pritikin allows), 10% fat & no nuts, seeds or oils (which is accordance with both Ornish & Pritikin) and a fish oil supplement (which is from the recommendations of Dr. Ornish).
But there is more...
He then moves on to breast cancer to show the power of a plant based diet in just 2 weeks in its ability to both slow down the growth rate of several types of breast cancer cells and also to actually kill breast cancer cells.
This study was done solely by the Pritikin group and used the usual Pritkin intervention diet which has been described many times in the literature.
From the actual study ...
"These results show that a very-low-fat, high-fiber diet combined with daily exercise results in major reductions in risk factors for BCa while subjects remained overweight/obese."Here is more details of the intervention.
"The subjects of this study were postmenopausal women attending the Pritikin Longevity Center Residential Program where they were given a low-fat (10-15% Kcal.), high-fiber (>40 gm/d) diet along with one hour of daily supervised exercise, primarily treadmill walking. The diet consisted of natural whole grains, fruits and vegetables with limited amounts (<3.5 oz) of fish, fowl or lean meat and nonfat milk." In the third Pritikin study, he looks at the effect of exercise and a plant based diet on cancer cells. In this study, they compared the control group (sedentary SAD) to those on the SAD for 14 years who exercised heavily and to those who were on the plant based diet with moderate exercise for 14 years. The Pritikin diet was 2x as powerful.
The same very low fat Pritikin diet, as described above, was used.
[As a side note, in Dr Greger's presentation, it is made to seem as if these participants went for a stroll each day. The truth is, at the center, everyone did 45 minutes of aerobics, 6x a week, in their target heart zone, which was based on a stress test. It is mentioned in the study as "treadmill walking." Well, many may have "walked" but it was very vigorous walking and not just a stroll. We monitored each subject and their heart rates. This was the same advice they were sent home with. And yes, as you can tell, most all these studies, except the latest one, happened during my tenure at Pritikin]
He then moves on to describe the mechanism by which this is happening and gets into the IGF-1 issue, using some of the same Pritikin studies and another Pritikin study showing that power of the program to lower IGF-1 in 12 days and how much lower it is in those following the Pritikin program for 14 years.
He then moves on to another study to show how vegans have the lowest IGF-1 levels. This is generally true, however, excess protein, even concentrated plant proteins can raise IGF-1 as has been discussed here many times. And, all of the above mentioned results on breast and prostate cancer, which he highlighted, including the lower IGF-1, were accomplished on the Pritikin Diet, which allowed for a small amount of animal protein.
The Pritikin Diet is a very low fat diet that is not vegan or vegetarian, and during the 12 day intervention in all the above studies, does not include any nuts and seeds and does include (though not based on) some white potatoes. While it allows some animal protein in the form of animal flesh (fish, chicken or wild game), egg whites and non-fat dairy, the total amount of animal products is carefully limited. Many consider it a very low fat, "near" vegetarian diet. Their research is not just new, but has been going on for over 30 years and is still current and valid. (see below)
In addition, in the discussion of diet and hypertension, Dr Greger asks the question, how long does it take to bring BP down eating a vegan diet. He then goes on to show Dr McDougall's study from 1995, which was able to lower BP 5-7% in just twelve days.
The McDougall Diet is a very low fat diet and during the 12 day intervention in the above study, it included little to no nuts and seeds and does include (though not based on) some white potatoes. I know, I was an intern there at the time.
As Dr Greger clearly shows, even as of this moment today, both of these programs are some of the most powerful science-based evidence we have for the power of a plant based diet.
I agree.
Thanks Dr Greger!
In Health
Jeff
PS as mentioned above, here is the full list and description of all the evidence from Pritikin (1981-2008)
http://www.pritikinresearchfoundation.org/research.htmlAnd these are from 2008 forward
Benign prostatic hyperplasia: does lifestyle play a role? Barnard RJ, Aronson WJ. Phys Sportsmed. 2009 Dec;37(4):141-6. Review.
Growth inhibitory effect of low fat diet on prostate cancer cells: results of a prospective, randomized dietary intervention trial in men with prostate cancer. Aronson WJ, Barnard RJ, Freedland SJ, Henning S, Elashoff D, Jardack PM, Cohen P, Heber D, Kobayashi N. J Urol. 2010 Jan;183(1):345-50. Epub .
Analyzing serum-stimulated prostate cancer cell lines after low-fat, high-fiber diet and exercise intervention. Soliman S, Aronson WJ, Barnard RJ. Evid Based Complement Alternat Med. 2011;2011:529053. Epub 2011 Mar 15.
Phase II prospective randomized trial of a low-fat diet with fish oil supplementation in men undergoing radical prostatectomy. Aronson WJ, Kobayashi N, Barnard RJ, Henning S, Huang M, Jardack PM, Liu B, Gray A, Wan J, Konijeti R, Freedland SJ, Castor B, Heber D, Elashoff D, Said J, Cohen P, Galet C. Cancer Prev Res (Phila). 2011 Dec;4(12):2062-71. Epub 2011 Oct 25.
A Short-term Diet and Exercise Intervention Ameliorates Inflammation and Markers of Metabolic Health in Overweight/Obese Children. Izadpanah A, Barnard RJ, Almeda AJ, Baldwin GC, Bridges SA, Shellman ER, Burant CF, Roberts CK. Am J Physiol Endocrinol Metab. 2012 Jun 19. [Epub ahead of print]
Effect of a Low-Fat Diet Combined with IGF-1 Receptor Blockade on 22Rv1 Prostate Cancer Xenografts. Konijeti R, Koyama S, Gray A, Barnard RJ, Said JW, Castor B, Elashoff D, Wan J, Beltran PJ, Calzone FJ, Cohen P, Galet C, Aronson WJ. Mol Cancer Ther. 2012 Jul;11(7):1539-46. Epub 2012 May 4.