For years, people thought that vegans and vegetarians ran the risk of protein deficiency. This concern arose in the 1970s after the publication of “Diet for a Small Planet” (1971). The protein recommendations in this book were criticized, in hindsight, as “needlessly stringent,” according to Vegan.com1, a comprehensive source of vegan information. Today, the opposite may be true, as many vegans may wrongly assume that their protein intake doesn’t matter much. Some may believe that they face no risk of protein deficiency as long as they eat enough calories and choose whole plant foods.
“The truth is that while it’s easy for vegans to get plenty of protein, it’s also easy to come up short,” the authors of Vegan.com state. “Unfortunately, it’s fair to assume that many vegans fall far short of achieving an optimal protein intake. It’s needlessly risky to believe that, as a vegan, you’re exempt from having to pay attention to protein.”
Protein foods break down into 22 naturally occurring amino acids, which are the building blocks of protein. Nine of these are “essential amino acids,” meaning that they must be obtained from food and that the body cannot produce them.
A key problem for vegans in their quest for “optimal” protein intake is that the digestibility of plant-based protein appears to be markedly less than that of animal products2, including eggs and dairy. Plant-based protein sources are often incomplete, missing important essential amino acids, and typically contain less branched-chain amino acids (BCAA), a group of three essential amino acids, compared to their animal-based equivalents.3-4
Furthermore, studies have shown that poorly constructed vegan diets might predispose individuals to deficiencies in macronutrients, such as protein and essential fatty acids, which humans must ingest because the body requires them for good health but cannot produce them on its own. Additionally, they may experience deficiencies in micronutrients (vitamin B12 and vitamin D, iron, zinc, calcium and iodine).5
This is why food selection should be a top-of-mind concern among vegans, and in particular finding high quality vegan protein sources.
The table below was adapted from a 2017 study published in the Journal of the International Society of Sports Nutrition.
Vegan-Friendly Food Sources5
|Protein||Pulses, grains, legumes, tofu, quinoa, nuts, seeds, vegetables|
|ALA (alpha-lipoic Acid)||Flax seeds, walnuts, chia seeds, hemp seeds|
|EPA* (eicosapentaenoic Acid)||Seaweed, algae|
|DHA (docosahexaenoic acid)||Microalgae oil, seaweed|
|Vitamin B12||Supplements, fortified foods, plant milks, nutritional yeast (fortified)|
|Iron||Legumes, grains, nuts, seeds, fortified foods, green vegetables|
|Zinc||Beans, nuts, seeds, oats, wheat germ, nutritional yeast|
|Calcium||Tofu (calcium set), fortified plant milks and juice, kale, broccoli, sprouts, cauliflower, bok choy|
|Magnesium||Legumes, nuts, tofu, seeds, whole grains, bananas, leafy greens|
|Iodine||Seaweed, cranberries, potatoes, prunes, navy beans, iodized salt|
|Vitamin D||Lichen-derived D3 supplements|
*EPA can be enzymatically converted from ALA and retro-converted from DHA.
Advantages of Seeds, and in Particular Hemp Seeds as a Vegan Protein Source
As highlighted in the chart, seeds stand out as excellent sources of vegan protein that also deliver the micronutrients of iron, magnesium and zinc. Hemp seeds, along with flax seeds and chia seeds, are also highlighted for plant-derived ALA, one of the three main types of Omega-3 fatty acids.
Hemp seeds should also be singled out for the amount of protein they provide per serving. Hemp seeds contain 9.2 grams of protein per 28 grams (1 ounce) of seed. In comparison, the nearest protein competitor, sunflower seeds, provide 5.8 grams of protein per 28 grams of seed. Ounce for ounce, hemp seeds contain 50% more protein than almonds, chia or flaxseed.
Proteins in food are broken down into amino acids during digestion, and then reassembled into human proteins according to need and availability. Hemp seeds, in particular, stand out because they not only contain all nine essential amino acids, but are also especially high in edestin and albumin, which are globular proteins that are easily digested.
In fact, research shows that 91% to 98% of the protein in ground hemp seed is digestible, meaning your body can use almost all of the amino acids in hemp protein powder for important bodily functions, such as repair and maintenance.6
The protein content of hemp seeds is an important distinction in food formulation, as formulators seek to carefully choose ingredients that are not only easily digestible but also deliver the most nutritional value to consumers. Combined with their many other health benefits—fiber, unsaturated fats, minerals, and antioxidants—hemp should be considered one of the most desirable plant-based proteins.
For more information on hemp seed nutritional content as it relates to Omega 3s, check out “Which Seeds Are Important Omega 3 Sources?”
More Vegan Protein Source Resources!
- Kniskern MA, Johnston CS. Protein dietary reference intakes may be inadequate for vegetarians if low amounts of animal protein are consumed. Nutrition. 2011;27(6):727–730. doi: 10.1016/j.nut.2010.08.024.
- Campbell B, Kreider RB, Ziegenfuss T, La Bounty P, Roberts M, Burke D, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2007;4:8. doi: 10.1186/1550-2783-4-8.
- Phillips SM. Protein requirements and supplementation in strength sports. Nutrition. 2004;20(7):689–695. doi: 10.1016/j.nut.2004.04.009.
- Rogerson D. Vegan diets: practical advice for athletes and exercisers. J Int Soc Sports Nutr. 2017;14:36. Published 2017 Sep 13. doi:10.1186/s12970-017-0192-9