4 replies to this topic

[Danail Bulgaria]

I found an interesting video, propagating, that vegeterian diets are actually damaging,not helping.

 

 

I wonder what do you think about that?

[timar]

I think that you haven't understood the video

 

Dr. Greger does certainly not claim that vegan diets are damaging, only that they can be or at least bring little or no improvement over omnivorous diets if vegans eat carelessly and don't take crucial supplements such as vitamin B12. Dr. Greger runs the website nutritionfacts.org where he presents information on nutritional science from a vegan perspective (I try to avoid the term propanda, but certainly his mission is to convince people about the health benefits of a vegan diet).

 

For well-founded counter perspective, look at the series nutritional scientists Dr. Stephan Guyenet recently published on his blog, wholehealthsource.org.

 

The only point where the evidence is really strong and unambiguous is that processed and grilled/charred meats are bad for you. Avoid them as much as you can. Moreover, there is a lot of evidence pointing towards detrimental effects of red meat, but it is not quite as conclusive.

 

My take: when one looks at the healthiest dietary patterns known from large-scale prospective and intercultural epidemiologic studies, they are all relatively low in animal products, compared to most modern diets, particularly in red meat, but high in fruits, vegetables and other whole plant foods. This observation is remarkably consistent with the evidence from other areas of nutritional science and biochemistry, showing the adverse effects of an exessive intake of saturated fat, animal protein and some other compounds associated with animal food. The only exceptions, where an increased intake of animal food actually shows beneficial effects is fish and low-fat fermented dairy.

 

Some rules of thumb that I personally adhere to:

1. Eat at least 10 times as much plant foods as you eat animal foods.
2. Eat fish at least as often as you eat meat.
3. Eat small servings of meat and fish, no more than 4 ounces.
4. Eat even smaller servings of high quality cheese, 1-2 ounces.
5. Eat red meat no more than once a week.
6. Avoid processed meat products as much as you can.
7. Eat natural yogurt instead of drinking milk.
8. Prefer organic and pastured animal food from regional farms.
9. Prefer wild-caught fish from sustainable fishery over farmed fish.
10. Cook animal foods gently, never burn them.

Edited by timar, 30 March 2015 - 03:09 PM.

[Brafarality]

Interesting knock on Paleo, Atkins and their ilk:

 

www.nytimes.com/2015/03/23/opinion/the-myth-of-high-protein-diets.html

[Darryl]

Yes, particularly red and processed meats.

 

Sinha, R., Cross, A. J., Graubard, B. I., Leitzmann, M. F., & Schatzkin, A. (2009). Meat intake and mortality: a prospective study of over half a million people. Archives of internal medicine, 169(6), 562-571.

Pan, A., Sun, Q., Bernstein, A. M., Schulze, M. B., Manson, J. E., Stampfer, M. J., ... & Hu, F. B. (2012). Red meat consumption and mortality: results from 2 prospective cohort studies. Archives of internal medicine, 172(7), 555-563.

Rohrmann, S., Overvad, K., Bueno-de-Mesquita, H. B., Jakobsen, M. U., Egeberg, R., Tjønneland, A., ... & Linseisen, J. (2013). Meat consumption and mortality-results from the European Prospective Investigation into Cancer and Nutrition. BMC medicine, 11(1), 63.

 

I believe the most informative studies for lifespan effect sizes for moderate lifestyle changes (with the least confounding) are the Adventist Health studies. Avoiding meat has an effect size comparable to regular exercise and nut consumption, and greater than avoiding obesity and smoking. 

 

Effects of individual risk factors on life expectancy

Variable                    Men       Women

Vegetarian diet           2.38 yrs  1.65 yrs

Vigorous Exercise         2.14 yrs  2.19 yrs

Frequent Nut Consumption  2.87 yrs  1.18 yrs

Avoid High BMI            1.51 yrs  1.90 yrs

Never Smoked              1.33 yrs  1.49 yrs

 

The current Adventist Health Study has found vegans to have a slight, though non-significant, edge over ovo-lacto-vegetarians, but most intriguing is the slight lead for pescetarians. Whether its just statistical noise, or because fish offer DHA/EPA, taurine,and other carninutrients without the saturated fats and immune stimulants of red & processed meat, is an important question for plant-based dieters like myself.

 

Orlich, M. J., Singh, P. N., Sabaté, J., Jaceldo-Siegl, K., Fan, J., Knutsen, S., ... & Fraser, G. E. (2013). Vegetarian dietary patterns and mortality in Adventist Health Study 2. JAMA internal medicine, 173(13), 1230-1238.

 

Edited by Darryl, 08 April 2015 - 08:22 PM.

[timar]

I believe the most informative studies for lifespan effect sizes for moderate lifestyle changes (with the least confounding) are the Adventist Health studies. Avoiding meat has an effect size comparable to regular exercise and nut consumption, and greater than avoiding obesity and smoking.

 

I agree that the Adventist Health Studies provides strong evidence in favor of a pescetarian or even vegan diet. Despite its large, homogenous collective and high methodological quality, though, it suffers from a peculiar possibility of residual confounding, which in my opinion is almost impossible to adequately control for. It is well known that at least within religious communities, faith and piety are strongly associated with better health and lower all-cause mortality. As their religion encourages Adventists to follow a vegetarian diet, those eating a vegetarian or vegan diet are likely "better adapted" to the belief system of the community and show a higher degree of piety. This does certainly not explain all the risk reductions seen in the AHS(II) - particularly those showing a linear dose-response curve consistent with other epidemiological studies. However, it seems likely to me that some of the marked risk increments from never-consumers to low-level consumers of animal products may be due to this "religious reverse causation" and should therefore be taken with a grain of salt.

Edited by timar, 09 April 2015 - 08:22 AM.