Even in a well-formulated real foods vegan diet there are many possible, even unavoidable, nutrient deficiencies. Several studies have shown that both vegetarians and vegans are prone to deficiencies in B12, calcium, iron, zinc, omega-3 long-chain fatty acids EPA & DHA, and fat-soluble vitamins like A & D. Let’s go through the most common ones and look for a solution that doesn’t involve pills, injections or fortified foods.
B12, beating a dead horse
Even though B12 deficiency is probably the most written about topic when it comes to nutrition and veganism, deficiencies are still very prevalent. There are studies showing that 68 % of vegetarians and 83 % of vegans are B12 deficient (1).
Vitamin B12 together with folate synthesizes DNA and red blood cells. It’s also involved in the conduction of nerve impulses and in production of the myelin sheath that protects nerves. That’s why B12 deficiency can cause issues like anemia, memory loss, fatigue, weakness, lethargy, etc. But we are all aware of the dangers of not getting enough B12, no need to beat this dead horse any longer. It’s time to ask: where are you getting your B12?
A common myth amongst vegans is that it’s possible to get B12 from plant sources like seaweed, fermented legumes, or brewer’s yeast. But plant foods only contain B12 analogs called cobamides that block the intake of, and even increase the need for true B12, cobalamin (2).
The recommended dietary allowance of vitamin B12 is 2,4 mcg a day for an adult. This amount can be covered by eating approx. 50 g of crickets or just 10 g of dried crickets in a form of cricket flour.
Using cricket flour in food preparation seems like a very efficient tool in preventing the dangers of B12 deficiencies.
Protein, is it complete?
Protein is not just something bodybuilders use to get bigger muscles, it is essential for everyone. We need it to build and repair all tissues, produce enzymes, hormones, and much more. We need amino acids for all that, to be more precise. We get those in our digestive tract by breaking down the protein we eat, and that’s where plant-based and animal-based proteins differ. The human body makes best use of protein that has a certain ratio of amino acids. Most animal proteins break down into a very favourable ratio of all nine essential amino acids (complete protein), however, the majority of plant sources offer proteins that don’t have the ideal ratio (incomplete protein) (3).
The quality of protein is affected not only by its amino acid profile but also by its digestibility. Plant sources are lacking in this regard because protein in intact plant cells could be less accessible to digestive enzymes and therefore be less bioavailable – not as easy to digested and absorb.
Recommended daily protein intake should be somewhere in the range of 0,8 – 1,8 g per kilogram of lean body weight (total weight minus fat). For example, let’s take a look at a lean active male weighing 70 kg (with 15% of body-fat) trying to maintain muscle mass. Let’s say he decides to eat approx. 90 g of protein daily. These are some of the options he has:
- Sirloin beef steak – 27,2 g of complete protein per 100 g = 331 g of meat
- Cooked chickpeas – 8,9 g of incomplete protein per 100 g = 1011 g of chick peas
- Raw broccoli – 2,8 g of incomplete protein per 100 g = 3214 g of broccoli
- Dried crickets – 67.8 g of complete protein per 100 g = 133 g of dried crickets
In order to satisfy his protein needs he would have to eat one of the following: 2 beef steaks, more than 4 cans of chickpeas (there are only 240 g of chickpeas in one 400 g can, the rest is water), or about 14 heads of broccoli! And we are not even considering the digestibility in these cases.
In contrast, you would only need about 133 g of cricket flour to cover your daily protein needs. Adding cricket flour to various traditional meals is an effective way to meet the different protein requirements we all have.
Omega-3s, a reliable source
Linoleic acid (omega-6) and alpha-linolenic acid (omega-3) are considered to be essential fatty acids because our bodies can’t synthesize them and we have to get them through our diets. They are both available in plants, but there is one caveat. These are short-chain fatty acids, and our bodies can only utilize their long-chain versions EPA & DHA. A large body of research has shown the benefits of these long-chain omega-3 fatty acids. They play a protective role in a wide range of diseases such as cancer, asthma, depression, cardiovascular disease, ADHD, and autoimmune diseases.
While it is possible for these short-chain amino acids to be converted into EPA & DHA, that conversion is very poor in humans: between 5-10 % for EPA and only 2-5 % for DHA (4). In general, vegans have 50 % lower EPA and nearly 60 % lower DHA levels than omnivores (5). Moreover, the conversion of ALA to DHA relies on sufficient zinc, iron, and pyridoxine levels, and those are nutrients that vegans are less likely to get enough of than omnivores.
In 100 g of crickets you will find approx. 2,8 g of omega-3 fatty acids (mostly EPA and ALA).
Crickets seem to be a good and largely overlooked source of essential fatty acids. Their daily use can help prevent the above mentioned diseases.
Iron, calcium and zinc, how much can you really absorb?
Iron, calcium and zinc are used throughout our bodies. They are essential for maintaining good immune functions, a healthy heart and muscles, strong bones, and an effective nervous system. We need to make sure that we get enough of them from our diet on a daily basis. The tricky thing is that minerals come in different chemical forms and bind to different molecules and that’s why it is not as straightforward as counting their total content in food.
For example, the bioavailability of calcium from plant foods is affected by their levels of oxalate and phytate, which are inhibitors that decrease the amount of calcium the body can extract (6). So while leafy greens like spinach and kale have a relatively high calcium content, the calcium is not efficiently absorbed during digestion. The same is true for Zinc. Brazil nuts that are amongst the foods with the highest Zinc content are also very rich in phytates. That means that the actual amount of Zinc absorbed and utilized will be much lower than the total amount of zinc these nuts contain (7).
Iron in animal foods is found mostly in heme form, which is easily absorbed by our bodies. On the other hand, plants only contain non-heme iron, which our bodies have a lot harder time absorbing (8). Plant-based forms of iron are also inhibited by other commonly consumed substances, such as coffee, tea, dairy products, supplemental fiber, and supplemental calcium. All of this might explain why vegans are often deficient in iron, calcium, and zinc (9).
Insects are a great source of highly bioavailable minerals. For example, Mopane caterpillar provides over a 100 % of the daily recommended dietary allowance of iron and zinc in just 100 g, and the same amount can cover over 17 % of our daily calcium needs. Similarly, a 100 g of cricket flour contains over a 100 % of the daily recommended dietary allowance of zinc, 62 % of iron, and 17 % of calcium (10).
To sum everything up, if you follow a vegan diet without any additional supplements or fortified foods, there is a high risk that you won’t get all the essential nutrients your body needs.
At SENS Foods, we believe that sensible vegans who want to stay healthy long-term and also minimize animal cruelty should include insects in their diet. We are sure that insects are a viable solution for many of the above mentioned deficiency problems.
1) Herrmann W. et al., ‘Vitamin B-12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians.’, Am J Clin Nutr. 2003, https://www.ncbi.nlm.nih.gov/pubmed/12816782
2) Watanabe F. et al., ‘Pseudovitamin B(12) is the predominant cobamide of an algal health food, spirulina tablets.’, J Agric Food Chem. 1999, https://www.ncbi.nlm.nih.gov/pubmed/10552882
3) Gertjan Schaafsma, ‘The Protein Digestibility–Corrected Amino Acid Score’, The Journal of Nutrition 2000, http://jn.nutrition.org/content/130/7/1865S.long
4) Davis BC. and Kris-Etherton PM., ‘Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications.’, Am J Clin Nutr. 2003, https://www.ncbi.nlm.nih.gov/pubmed/12936959
5) Magdalena S. Rosell et al., ‘Long-chain n–3 polyunsaturated fatty acids in plasma in British meat-eating, vegetarian, and vegan men’, The American Journal of Clinical Nutrition, 2005, http://ajcn.nutrition.org/content/82/2/327.abstract
6) Connie M. Weaver et al., ‘Choices for achieving adequate dietary calcium with a vegetarian diet’, The American Journal of Clinical Nutrition, 1999, http://ajcn.nutrition.org/content/70/3/543s.full
7) Janet R. Hunt, ‘Bioavailability of iron, zinc, and other trace minerals from vegetarian diets’, The American Journal of Clinical Nutrition, 2003, http://ajcn.nutrition.org/content/78/3/633S.long
8) Waldmann A. et al., ‘Dietary iron intake and iron status of German female vegans: results of the German vegan study.’, Ann Nutr Metab. 2004, https://www.ncbi.nlm.nih.gov/pubmed/14988640
9) Craig WJ., ‘Nutrition concerns and health effects of vegetarian diets.’, Nutr Clin Pract. 2010, https://www.ncbi.nlm.nih.gov/pubmed/21139125
10) FAO (Food and Agriculture Organization of the UN), ‘Edible insects – Future prospects for food and feed security’, Rome 2013, http://www.fao.org/docrep/018/i3253e/i3253e.pdf