2.21 Type of Protein
Protein is not divided into different types like fats and carbohydrates, however, there is a difference in regards to the amino acids in the protein and the other nutrients that come along with a specific protein source.
Your body is able to make some amino acids from others, which it links together to make proteins. However, certain amino acids you simply are not able to make and thus they must come from the diet. These are called “essential amino acids”. If you do not eat enough essential amino acids, the body will not have the building blocks that it needs to make enough protein. There is little research on the link between essential amino acids in your diet and heart disease risk.
Scientific evidence strongly supports eating a large majority of your protein from plant sources such as fruits, vegetables, beans and grains1-2. This will get you more than enough of the essential amino acids3. There is no need to try to combine different plant protein sources (like eating brown rice and beans together). A whole food plant based diet will give you all you need.
On the other hand, eating an excess amount of protein from animal sources significantly increases the risk of heart disease, many types of cancer and stroke. You should get as little protein as possible from animal sources such as meat, seafood and dairy.
Think of it this way…one of the most important factors about the type of protein you eat is the other nutritional value that is coming along with it. For example, a large steak has a lot of protein, but will be high in cholesterol, saturated fat and calories, which will have a negative impact on your heart health. Similarly, pork can have a lot of protein, but likewise is frequently high in fat and high in sodium. Surprisingly, even poultry and seafood (especially shrimp), are unhealthy protein sources.
Including lean proteins such as boneless, skinless chicken breast still have major negative health impacts. No matter how “lean” the meat is, there is still a large amount of cholesterol and saturated fat…of course way more than a plant source which will have none. Also once again, you will not find any health promoting fiber in animal based sources of protein. Lastly, the actual animal protein itself has been shown to promote cancer and heart disease. The animal protein (not just the cholesterol and saturated fat) does this through many mechanisms including
- Increased insulin like growth factor which promotes cancer growth4
- Increased TMAO – a toxin that damages artery walls and promotes atherosclerosis5
- Heme iron – the type of iron found in animal proteins which promotes the development of “free radicals” which damage the body6
- High phosphorus which promotes a molecule called FGF23 which damages artery walls and promotes atherosclerosis7
- High sulfur contained in the amino acids promotes an acidic environment8
One last reason to avoid meat. Endotoxins from bacteria on animal based foods causes inflammation9.
It is pretty clear that the healthiest source of protein is plant based protein. Eating more plant protein simply will lower your risk of heart disease and overall death significantly1 and making plant protein 100% of what you get is the most effective way including one of the key components to reversing heart disease.
Many people are surprised to find out that 100 calories of broccoli has almost twice the amount of protein as 100 calories of beef. Get a large majority of your protein, or even 100% of it, from plant based sources. Vegetables, beans, nuts and soy (such as tofu) are very healthy protein sources.
If a predominately plant-based protein source is the healthiest, why then do the USDA Dietary Guidelines allow for significant amounts of animal protein? The USDA is an organization who needs to both support big agribusiness and give dietary guidelines which is a big conflict of interest since recommending against a certain product (i.e. meat or dairy) would hurt the same people they are supposed to advocate for. They also do not report what is “ideal” for Americans to eat, but what they think is realistic. This approach has clearly not worked considering the rates of chronic diseases in the U.S.
1. Association of Animal and Plant Protein Intake With All-Cause and Cause-Specific Mortality. JAMA Intern Med. October 2016
2. Cancer Incidence on Vegetarians: Results From The European Prospective Investigation Into Cancer and Nutrition. 2009 May;89(5):1620S-1626S
3. Young VR , Pellett PL. Plant proteins in relation to human protein and amino acid nutrition. Am J Clin Nutr. 1994;59(5 Suppl):1203S-1212S
4. Allen NE, Appleby PN, Davey GK, Kaaks R, Rinaldi S, Key TJ. The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans. Cancer Epidemiol Biomarkers Prev. 2002; 1(11):1441-1448
5. Tang WH, Wang Z, Levison BS, et al. Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. N Engl J Med. 2013;368(17):1575-1584
6. Atamna H. Heme, iron, and the mitochondrial decay of ageing. Ageing Res Rev. 2004;3(3):303-318
7. Xiao Y, Peng C, Huang W, et al. Circulating fibroblast growth factor 23 is associated with angiographic severity and extent of coronary artery disease. PLoS One. 2013;8(8):e72545
8. HC Sherman and AO Gettler. The Balance of Acid-Forming and Base-Forming Elements in Foods, and its Relation to Ammonia Metabolism. J. Biol. Chem. 1912 11: 323-338
9. Erridge C, Attina T, Spickett CM, Webb DJ. A high-fat meal induces low-grade endotoxemia: evidence of a novel mechanism of postprandial inflammation. Am J Clin Nutr. 2007 Nov; 86(5):1286-92