Patients frequently come to me asking for help with fatigue. Often, after reviewing their diet journal, the cause is quite clear: protein deficiency. It amazes me to hear this typical response when I explain the need for more protein: “Dr. Dunn, I get all the protein I need from fruits and vegetables.” Indeed, a quick internet search substantiates their claim. It appears to be a popular, yet misguided protein myth.
Common protein deficiency symptoms include: fatigue, hair loss, unstable blood sugar including hypoglycemia and consequent craving for carbs, swelling, thin brittle nails, muscle soreness and cramps, slow healing, sleep issues, headache, nausea, fainting, depression/anxiety, weakened immune system, decreased muscle mass and strength, irritability, apathy, failure to thrive in children and with severe protein deficiency; death.
Another protein myth is that protein intake estimates are excessive and that adults only need about 20 grams of protein daily. One egg has about 9 grams of protein. In my book, The Family Guide to Naturopathic Medicine, I suggest 45-50 grams of protein for adults 110-130 pounds and 55-60 grams of protein for adults of 160 pounds engaged in moderate daily activity; more if engaged in regular strenuous exercise. Without sufficient protein intake symptoms will occur as above, whether vegan or carnivore.
The protein myth I most often hear is that all proteins are created equal. This misinformation is behind the most frequent cause of protein deficient ailments.
Not all proteins are created equal. A protein is made up of amino acids, and to be a complete protein there must be nine amino acids present in the food: histadine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. These nine amino acids are called essential amino acids, meaning the body cannot make them; they must come from our diet. While these nine amino acids are necessary to make a complete protein, that is only part of the protein story.
The quality and viability of a protein to sustain optimal health is dependent on several factors. For example, an egg is a readily digestible complete protein with optimal amounts of each amino acid and optimal proportions of the nine amino acids, all of which are elements for optimal human health. The egg is the standard by which other proteins are measured.
Animal sources of protein are the most balanced form of single food protein for the body. Organic animal protein offers many health benefits including anti-inflammatory oils and prostaglandins, hormonal like substances which affect our health, and vitamin B12 (see website newsletter B12) which is absent in vegan foods. In contrast to organic meat, non-organic farm raised animal foods are pro-inflammatory and full of toxins that promote diabetes, heart disease, dementia and cancer.
The digestive system breaks down proteins into amino acids which are absorbed into the blood stream and shuttled to target organs and cells for reassembly into human proteins. These human proteins create muscles, nerves, neurotransmitters, enzymes and most everything else in the body. If a person is relying on a single complete yet poorly balanced protein, as found in some vegan diets, problems will arise.
Avocados, peaches, spinach and broccoli are four examples of complete protein foods that lead to serious protein deficiency illness if used as the sole source of dietary protein, because of their poor essential amino acid volume and or amino acid ratios. They have all the essential amino acids, but one or more of the amino acids is in very short supply and or out of proportion.
For example, when it comes to fruits and vegetables, avocado is touted as being a top non-animal protein source. I would disagree. An avocado has good ratios of amino acids, but by volume one would need to eat about eight medium sized avocados to get the same volume of essential amino acids offered in one egg. Or, 48 avocados a day to provide the necessary essential amino acid intake for a 160 pound adult. Relying on fruits and vegetables as a viable source of protein in my opinion is not realistic.
However, there are non-animal protein sources to consider. Non-animal proteins can vary considerably, some being more beneficial than others. Hemp protein powder is a good example of a well balanced bioactive globulin protein that is easy to digest and rarely allergenic, unlike soy protein, a common allergen, containing trypsin inhibitors that interfere with protein digestion.
The most common amino acid deficiency in the vegan diet is lysine; if a person gets enough lysine then most likely they are getting enough total protein. Lysine rich foods include: lentils and other legumes, quinoa, pistachios and pumpkin seeds. To ensure a vegan based complete and usable protein intake, thoughtful food combining is necessary.
Grains are low in lysine and legumes are low in methionine. However, by combining the two, deficiencies of these amino acids are accounted for. Legumes/beans and grains (wild rice, quinoa, amaranth, buckwheat, millet; the healthiest grain choices) at the same meal provides a good compliment of amino acids. The addition of nuts (not peanuts) and seeds such as sunflower, sesame or chia, will further ensure a complete supply of amino acids.
Sprouting seeds and legumes together will often enhance their nutritional value. For example, cooked lentils are deficient in methionine, while sprouted lentils have good amounts of methionine. By sprouting quinoa the vitamin content is enhanced. Quinoa can be sprouted and ready to eat raw in salads after just 2-4 hours of soaking in clean water.
There is one big caveat regarding vegan derived dietary protein: just because a person receives the requisite daily amount of non-animal protein doesn’t mean they will thrive. There are several reasons for this.
Many people do not digest vegan sourced protein very well and those individuals, despite a healthy and well balanced vegan diet, will suffer. Initial symptoms may show with increased gas and bloating which comes from poorly digested food. If these symptoms are ignored, inflammation will ensue eventually leading to symptoms of protein deficient malnutrition.
Grains and legumes contain compounds that inhibit the action of protein digesting enzymes. For example, trypsin inhibitors found in legumes inhibit the digestion of protein. Lentils are also high in phytates which can reduce bioavailability of dietary minerals, yet this concern can be minimized by soaking the lentils in warm water overnight before cooking.
Regarding the mental emotional level of health, tryptophan is another essential amino acid not well represented in a vegan diet. Adequate intake of tryptophan helps keep us happy, calm and even keeled.
In summary, adequate and healthy protein intake is essential for optimal health and survival. Total protein content of a food does not reflect the protein quality of that food. At least four factors are essential in assessing the quality of a protein:
- are all essential amino acids present
- are the amino acid ratios and proportions optimal
- is the protein readily digestible
For those committed to a vegan diet, daily protein requirements can be met, however, I always recommend to my patients: ‘listen to your body’. Some people are able to thrive on a vegan protein based diet, and if this is the case for an individual, great. However, it is my experience that most people need to include some organic animal based dietary protein in order to achieve and maintain optimal health and well being.
Beyond the nutritional status of protein decision making are the politics, morals and ethics involved in protein selection. For this subject I suggest Lierre Keith’s book The Vegetarian Myth as an excellent reference and review.
I hope you have enjoyed this lengthy newsletter. As always, comments and feedback are welcome.
Jon Dunn, ND