Discussion Board

Vegan proteins may reduce risk of cancer, obesity, and cardiovascular disease by promoting increased glucagon activity.

McCarty MF.
Source Nutrition 21/AMBI, San Diego, CA, USA.

Abstract

Amino acids modulate the secretion of both insulin and glucagon; the composition of dietary protein therefore has the potential to influence the balance of glucagon and insulin activity. Soy protein, as well as many other vegan proteins, are higher in non-essential amino acids than most animal-derived food proteins, and as a result should preferentially favor glucagon production. Acting on hepatocytes, glucagon promotes (and insulin inhibits) cAMP-dependent mechanisms that down-regulate lipogenic enzymes and cholesterol synthesis, while up-regulating hepatic LDL receptors and production of the IGF-I antagonist IGFBP-1. The insulin-sensitizing properties of many vegan diets--high in fiber, low in saturated fat--should amplify these effects by down-regulating insulin secretion. Additionally, the relatively low essential amino acid content of some vegan diets may decrease hepatic IGF-I synthesis. Thus, diets featuring vegan proteins can be expected to lower elevated serum lipid levels, promote weight loss, and decrease circulating IGF-I activity. The latter effect should impede cancer induction (as is seen in animal studies with soy protein), lessen neutrophil-mediated inflammatory damage, and slow growth and maturation in children. In fact, vegans tend to have low serum lipids, lean physiques, shorter stature, later puberty, and decreased risk for certain prominent 'Western' cancers; a vegan diet has documented clinical efficacy in rheumatoid arthritis. Low-fat vegan diets may be especially protective in regard to cancers linked to insulin resistance--namely, breast and colon cancer--as well as prostate cancer; conversely, the high IGF-I activity associated with heavy ingestion of animal products may be largely responsible for the epidemic of 'Western' cancers in wealthy societies. Increased phytochemical intake is also likely to contribute to the reduction of cancer risk in vegans. Regression of coronary stenoses has been documented during low-fat vegan diets coupled with exercise training; such regimens also tend to markedly improve diabetic control and lower elevated blood pressure. Risk of many other degenerative disorders may be decreased in vegans, although reduced growth factor activity may be responsible for an increased risk of hemorrhagic stroke. By altering the glucagon/insulin balance, it is conceivable that supplemental intakes of key non-essential amino acids could enable omnivores to enjoy some of the health advantages of a vegan diet. An unnecessarily high intake of essential amino acids--either in the absolute sense or relative to total dietary protein--may prove to be as grave a risk factor for 'Western' degenerative diseases as is excessive fat intake. http://www.ncbi.nlm.nih.gov/pubmed/10687887

Thanks for posting this, Steelhead! I recall that from the film, Forks Over Knives, higher levels of animal protein were associated with higher cancer rates but that higher levels of vegetable protein were not. However, the higher levels of protein (animal or vegetable) may contribute to other problems, especially bone demineralization and kidney disease.

It is good to know that we can get all of the protein we need form starches and veggies!

From the above quoted article:

"Risk of many other degenerative disorders may be decreased in vegans, although reduced growth factor activity may be responsible for an increased risk of hemorrhagic stroke."

I sure would like to know more about that! It is rarely discussed and it seems rather important.

Ginger:

See this: http://www.ncbi.nlm.nih.gov/pubmed/12944100

I found it very interesting!

Indeed, very interesting. Thanks for that.

i have concern about this.....
i think this needs further discussion.....
harry

I do not think you will convince moms to feed their kids a vegan diet if you tell them their sons will end up with shorter stature. I do not know if he was correct but Pritikin said it was fat that caused greater stature.

Didi

Vegan kids are not necessarily shorter:
http://www.nealhendrickson.com/mcdougal ... pletoo.htm

You Can Have Height, Strength, and Life

If you met my 3 children you would find a serious contradiction with the above discussion. My daughter, Heather, is an inch taller than Mary. My oldest son, Patrick, is 3 inches taller than I am, and my youngest son, Craig, is 2 inches taller (and the boys are very muscular, too). They were all raised on the McDougall diet. So how did they grow so tall and strong?

Feeding a high-fat, high-protein diet is only one way for a person to attain greater body size. The alternative, healthy way is to encourage natural development by allowing the growth plates of a child’s long bones to remain open longer, into their mid and late teens. The growth plates (called epiphyseal end plates) are located at the ends of the long bones and, as the name implies, this is where growth occurs. A rise in sex hormones (primarily estrogen) after puberty causes the growth plates to close.35,36 The rich Western diet prematurely raises sex hormones, causing precocious puberty, and prematurely closes the adolescent’s growth plates.36 (For more information on precocious puberty and diet see the McDougall Program for Women book.) A healthy diet, like the McDougall diet, allows puberty to occur at the correct age (say 14 to 17 years rather than 8 to 12) – thereby growth continues into the late teens. Therefore, you can have it all for your children and grandchildren – tall strong bodies and good health by feeding them plentiful amounts of delicious meals, like oatmeal for breakfast, vegetable soups and sandwiches for lunch, and bean burritos and spaghetti for dinner. (People from some Asian countries, like Japan, and from our own past are small because of a relative deficiency of food (calories) during their adolescent growing years.34,37)

Mark F. McCarty (author of the study that was mentioned in the opening post) has also written a book about the benefits of a low-fat, low-salt, whole-food vegan diet. Free copy of the book can be downloaded from there:

Low-Fat, Low-Salt, Whole-Food Vegan: Staying Lean and Healthy into Ripe Old Age

I haven't read the book yet. Hehe, it seems that McCarty can't be blamed for lack of references...

Thanks for the link. I'm on page 15 and am finding it very worthwhile. Clearly written and very much in line with McDougall, Novick, Esselstyn, Fuhrman, and Ornish.

From page 5 --
From page 8 --
The author gives both sides of arguments a fair hearing (e.g., baked potatoes, caffeine, fish oil, etc.)

I agree that McCarty is mainly on the same path with the doctors recommending plant-based diets. However, he seems to recommend more supplements than for example Dr. McDougall. If I understood correctly, then McCarty is a researcher working for NutriGuard. This may be something worth considering before buying all the products he recommends... The vast reference list includes many interesting articles. I have picked quite many of those for further reading.

Thanks again! I prefer to take my supplement advice from people who are not involved in the supplement business, although I do consider their viewpoints.

Unfortunately, omega-3 supplementation still seems to be a controversial topic, even among experts who are not involved in the supplement business. Ornish-yes, McDougall-No, Esselestyn-No, Fuhrman-Yes: algal, Greger-We aren't sure. (Fuhrman does selll supplements.)

I got to page 32 last night and find the e-book worthwhile, even when the advice conflicts with McDougall/Novick. McCarty has a huge amount of respect for McDougall, Esselstyn, Ornish, Pritikin and others in the low-fat, whole foods vegan vanguard.

I know that some prefer not to read conflicting advice, but I find it helps my resolve to know both sides of contentious issues. E.g., baked russet potatoes are a good food (McDougall), but there are probably more optimal sources for starch calories (most everyone else).

According to Dr. Greger, Spirulina should be avoided due to risks of it being contaminated with hepatotoxins or neurotoxins.

http://nutritionfacts.org/topics/spirulina/

McCarty has published an article about spirulina:

Clinical Potential of Spirulina as a Source of Phycocyanobilin

There is a chapter about the safety of spirulina, but I think that McCarty does not deal with the negative sides which Dr. Greger mentions. This is a good reason why one should be more skeptical about claims of those who sell certain products. When there is money to be made, then there is often more temptation to avoid some issues.

Exactly!

Before I posted my Greger caution, I googled for McCarty and toxins. The article MikkoL cited was the best I could find, and I didn't think it was very good.

Dr. McDougall and Jeff Novick sell only services, books, and DVDs. While I can find honest clinicians and researchers who disagree on a minor point or two, they appear to be highly reliable. Same with Esselstyn, Campbell, Vogel (Pritikin Program), Ornish and Greger. (Honest, well intentioned people can still disagree -- the nature of evolving science.)

Fuhrman sells products. but it really is hard to find too much that conflicts with his free advice, whether or not you choose to purchase his supplements.

McCarty is a bit more commercial than Fuhrman. Still, I have found the book to be quite helpful and reliable, with the sole exception of spirulina -- so far -- at page 72.