Nutrition

 

It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes1 

Nutrition

Leading nutritional and dietetic associations in the US, Australia and around the world regard vegan diets as complete. It is their and other scientific institutions’ opinions3,4 that with proper planning, all the nutrients necessary for good health can be readily obtained from a vegan diet1,2. The Dietician’s Association of Australia and Australia’s top health experts agree with those in other parts of the world that well-planned vegan diets are safe and healthy for all age groups2.

The following are the key hot topics for those that are changing to a vegan diet:

Protein
Carbohydrates
Soy
Fatty Acids
Iron
Vitamin B12
Vitamin D
Calcium
Zinc
Iodine
References

Click here for a downloadable infographic on the vegan food plate (PDF)


Disclaimer:

The contents of this website are for educational purposes and are not intended to offer personal medical advice. It is the responsibility of the individual to seek the advice of a GP or other qualified health provider with any questions they may have regarding a medical condition.


Protein

One of the most common questions a vegan is asked is “where do you get your protein?” This question probably stems from the myth that you can only get protein from meat. This is completely wrong. Historically, the macronutrient “protein” was discovered through experimentation with animal products around the eighteenth century. As a result, “protein” became somewhat misleadingly only associated with “meat”. Two centuries later, and it is still taking time for people to begin to recognise that plants can provide all the essential protein we need in our diet.

So what is Protein and how do I get it from Plants?

Protein is made up of Amino Acids connected in chains. There are 21 different types of amino acids that our body needs to function properly. The types of protein depend on how the amino acids are arranged and the different kinds of amino acids in the chain.

Amino Acids can either be essential or non-essential. Out of the 21 amino acids, 13 are non-essential because they are produced by the body. The other 8 (sometimes 9) amino acids are called the essential amino acids as our body cannot produce them. We therefore need to obtain these amino acids through the food we eat.

protein2

Although plant wholefoods contain all amino acids, some plant foods may be low on one essential amino acid while others may be higher in another. For example, grains (rice, buckwheat, oats, rye, wheat, barley etc) are low in the essential amino acid Lysine, however they are high in the essential amino acids methionine and cysteine. Legumes (beans, chickpeas, lentils, soybeans etc) are low in the essential amino acids methionine and cysteine, however they are high in the essential amino acid Lysine. As long as vegans consume a variety of plant based foods, it will ensure all necessary amino acids are met.

Combining different plant wholefoods is an easy way to ensure all protein needs are met. For inspiration, look around the world’s traditional foods such as Indian (Dhal with rice), Mexican (beans and corn), Middle Eastern (lentils, beans and rice), European (pea soup and baguette) to name a few.

The National health and Medical Council5 recommends  daily intake (RDI) of protein as follows:

      • Men: 0.84g/kg body weight of protein a day
      • Women: 0.75g/kg body weight per day
      • Pregnant women: 1.0g/kg body weight per day

Primary vegan protein sources include legumes such as beans, peas and lentils, nuts and seeds, soy products and grains such as brown rice, amaranth and quinoa.

Examples of plant protein foods and their protein content are6:

Example of Plant Protein sources

Click here for a downloadable info-graphic on vegan protein sources (PDF)

The following two links are recommended easy reading for those who seek more information about plant protein:


Carbohydrates

Unscientific fad diets such as the Atkins and the Paleo-style diets have had a hand in promoting Carbohydrates as the leading macronutrient responsible for obesity and disease in the western world.

Carbohydrates are the main source of fuel for the body, the brain, the circulatory system and the nervous system. Leading nutritional institutions and studies3,4 recommend consuming between 45-70% of calories from unrefined carbohydrates. A high Carbohydrate diet can therefore be a very healthy diet as long as it focuses on unrefined carbohydrates (simple or complex), such as whole grains, brown rice, pumpkin and sweet potato.

Simple and complex carbohydrates are naturally occurring carbohydrates that appear in wholefoods such as fruits, vegetables, legumes, nuts, starchy vegetables and whole grains.

Processed or refined carbohydrates, such as white bread and white rice lose nutrients such as fiber, iron and folate and other nutrients in the process, and may have added sugar and salt.  Therefore these refined/ processed carbohydrates are the ones to avoid.

Click here for The Harvard school publication offering more advice on carbohydrates.


Soy

Soy

Soy is a high protein source popular with many vegans. It is of course not essential, and vegans can live a healthy life without it.

Soy has received a lot of controversy in the past few years. As consumption has increased so have queries into its nature and health effects. The debated issues surrounding soy are mainly due to one of its components, called Isofalvone or Phytoestrogen “the plant oestrogen”. These Phytoestrogen, like oestrogen, are thought to bind to oestrogen alpha and beta receptors in women. The binding of the regular steroid hormone oestrogen to those receptors is a known mechanism in cancer growth. However studies have shown this to be an invalid concern for phytoestrogen as it does not activate the receptors in a similar way to the steroid hormone oestrogen. For a list of reviews, retrospective and observational studies on the evidence of soy and breast cancer click here.

People avoid soy as they’ve read that it causes cancer, thyroid problems and perhaps even “man boobs”.  These beliefs are not supported by the science. None of these health problems have been found to occur in humans who eat edamame, tofu, tempeh or soy milk made entirely of whole soy beans. In fact, traditional soy foods have been shown to lower the IGF-1 cancer promoting hormone7. Based on science, the only soy foods to avoid are soy isolates (such as soy protein for shakes), which have been linked to higher levels of cancer promoting IGF-1 hormone.

Soy also contains “Phytates” that have the potential to bind to minerals and lower their absorption from food.

There are many scientific publications and peer reviewed articles on the benefits of Soy and its use in the prevention of some cancers and diseases. Some of the easier reads which we have found and recommend are:

      • Soy and your health by The Physicians Committee for responsible Medicine (PCRM), led by Dr Neal Barnard. It is an overall summary of the research behind the benefits of Soy in cancer prevention .
      • Soy by Registered Dietician, Jack Norris, presents an introduction summary to the issues with Soy based on scientific publications
      • A Pubmed review article published by the Victorian Government also provides information about Soy and its benefits

Fatty Acids

Omega -3 (alpha-linolenic acid) and Omega -6 (Linoleic acid) are the two essential fatty acids, which the body needs but cannot produce, and therefore have to be obtained from our diet. It is important to include those two fats daily, and within the proper ratio, as they compete with each other in their paths in the body. The Standard American diet (S.A.D), to which the Australian diet has a striking resemblance, have become very high in Omega-6 and low in omega 3, causing many health issues.

While Omega-6 is easily obtained from many sources, more care needs to be taken with Omega-3.  The National health and Medical Council5 recommends daily intake (RDI) of Omega-3 essential fatty acids to be:

      • Men: 1.6g per day
      • Women: 0.9g per day
      • Pregnant women: 1.15g per day

Examples of some Omega-3 essential fatty acids plant foods are6:

Click here for a downloadable info-graphic on vegan omega3 sources (PDF)

Plant sources of omega-3s are all high fiber and rich in other nutrients. Edamame, pepitas, chia seed and walnuts contain omega-3s and also contain protein. Squash is very high in omega-3s and is also a great source of vitamin A and vitamin C. Linseed/ flaxseed are high in omega-3’s and are easy to incorporate into baked goods, smoothies, and a variety of recipes. Note, in order for the body to absorb Omega-3 from the seeds, the seeds have to be ground (spice or coffee grinder). Once ground, to protect them from oxidative damage, it is recommended that they be stored in a plastic bag in the freezer.

Omega-6 fats are found in vegetable oils ( sesame, sunflower, corn), leafy vegetables, nuts and seeds. In a plant based diets, the amount of omega 6 consumed is typically lower than the standard American/Australian diet, which is a good thing.

Omega 3 Supplements for vegans, if needed, include algae-derived supplements which are cruelty free and environmentally sustainable and free of contaminants from fish oil.

The following links provide more information on essential fatty acids


Iron

iron

With basic knowledge, vegans can easily obtain their iron needs from plant based sources.

The National health and Medical Council5 recommends daily iron intake levels as follows:

      • Men: 8mg
      • Women: 18mg
      • Pregnant women: 27mg
      • Post-menopause women: 8mg

Examples of iron quantity in common plant based foods are6:

iron

Click here for a downloadable infographic on vegan iron sources (PDF)

Plant foods rich in iron are:

      • legumes (Soy beans, lentils, chickpeas, tempeh, tofu, black beans, Pinto beans),
      • Vegetables (Spinach, Collard, Bok Choy, Green Beans, broccoli, kale),
      • Fruits (watermelon, dried apricots, dried raisins, dried figs);
      • nuts (walnuts, cashews, pistachios, pin nuts),
      • Seeds (sunflower, sesame, pumpkin and chia seeds)
      • grains (Quinoa, fortified cereals, oats)
      • Others such as dried thyme, dried parsley

Absorption of iron can be an issue in some cases.  Here are some tips:

      • Include a source of vitamin C with meals, (such as a kiwi fruit, orange, strawberries, berries, lemon, tomatoes).
      • Avoid coffee and tea 1-2 hours before or after meals.
      • Do not take an iron supplement with a high calcium meal or with a calcium supplement, as calcium will inhibit the absorption of iron.

The following links provide more information on iron on a vegan diet:


Vitamin B12

B12

Recent studies9 show that we are all at risk of  Vitamin B12 deficiency  regardless of our diet.  In the modern world, the most reliable and simple way to manage this is via a supplement.

B12 is made from an anaerobic bacteria originating in the soil and commonly found in the gastrointestinal tract of animals. In the past we obtained our needs via the bacteria on the plants we eat, and in animal products. Nowadays with the advent of factory farming and the use of pesticides, the availability has changed and B12 deficiency is increasingly common. An illuminating fact is that 90% of B12 supplements manufactured today are fed to factory farmed animals in order to ensure that the meat is a source of B12. To know more about B12 supplementation to farmed animals click here.

Vegans are just as vulnerable to this deficiency so are encouraged to eat fortified foods and/or take a supplement. Examples of B12 supplements are the sublingual varieties 1000mg taken 3-5 times a week or as directed by your GP.

The following links provide more information on vitamin B12:


Vitamin D

Whether we are vegan or not, most of our vitamin D comes from exposing our skin to the sun. Vegans are at equal risk of deficiency if they are unable to obtain a safe level of sun exposure. In this case a supplement may be needed which are available from vegan sources. The following are the key details on supplements available:

vit DVitamin D2 (ergocalciferol) is the vegan version of vitamin D, whereas vitamin D3 (cholecalciferol) is animal derived.

There are now vegan versions of vitamin D3 available on the market based on Lichen (algae derived).

Both Vitamins D2 and D3 are effective; however, it might take more vitamin D2 to achieve the levels required.

Vitamin D is found in a very limited number of foods, such as Fortified soy milk.


Calcium

Due to strong marketing over many years, calcium has become synonymous with dairy. In reality there are many excellent plant sources of calcium including  hard tofu, tahini, most  green leafy vegetables such as Kale and Asian greens, and calcium-fortified soy products.

To get the most calcium benefit from plant based foods,  a variety of low oxalate plant foods are recommended. This is due to the fact that Oxalic acid binds to calcium in the gut reducing the amount absorbed. The plant foods richest in calcium and low in oxalic acid are Kale, Bok Choy and broccoli. Calcium

The National health and Medical Council5 recommends daily calcium intake as follows:

      • Men: 1000mg
      • Women: 1000mg
      • Pregnant women: 1000mg
      • Post-menopause women: 1300mg

Examples of some Plant foods rich in Calcium are6:

Examples of Calcium rich Plant Foods

Click here for a downloadable infographic on vegan calcium sources (PDF)

The following links provide more information on Calcium:


Zinc

Zinc is only needed as a trace mineral in the human body. One challenge specific to vegans is due to the action of “phytates” found in some plant sources of zinc such as spinach. Phytates have been shown to reduce zinc absorption. Due to the absorption issues, vegans should aim for a higher intake than the RDI. The negative effect of Phytates is managed by methods such as soaking, heating, sprouting and fermenting

Protein increases the absorption of zinc, therefore good plant sources include Baked beans, chickpeas, and nuts (such as cashews and almonds), Tofu, Tempeh, wholegrains and fortified cereals.

The National health and Medical Council5 recommends daily zinc intake as follows:

      • Men: 14mg
      • Women: 8mg
      • Pregnant women: 11mg

Examples of Plant foods rich in Zinc are8:

Examples of Zinc rich Plant Based Foods

Click here for a downloadable infographic on vegan zinc sources (PDF)

The following links provide more information on Zinc:


Iodine

Iodine

The risk of iodine deficiency on plant based diet is avoided with consumption of iodised salt and sea vegetables, such as sea weed. Care should be taken to avoid over consumption of iodine.

The National health and Medical Council5 recommends daily intake of iodine as follows:

      • Men: 150 µg
      • Women: 150 µg
      • Pregnant women: 220 µg

Best sources of iodine for a vegan are: seaweeds such as Wakame, dulse, kombu and nori. Nori is relatively low in Iodine and a couple of sheets can be eaten daily. Wakame, Dulse and kombu are very high in Iodine, therefore a couple of light drizzles on food once a week is enough.

The following link provides more information on Iodine:

      • Iodine by Registered Dietician, Jack Norris

References

[1] Craig WJ, Position of the American Dietetic Association: vegetarian diets. Journal of the American Dietetic Association 2009; 109(7):1266-1282

[2] Dieticians Association of Australia. 2013. Vegan Diets. [ONLINE] Available at: http://daa.asn.au/for-the-public/smart-eating-for-you/nutrition-a-z/vegan-diets/.

[3] Physicians Committee for Responsible Medicine. 2014. Health and Nutrition. [ONLINE] Available at: http://www.pcrm.org/.

[4] Campbell, T. Colin and Thomas M. Campbell II. The China Study. Dallas, TX: BenBella Books, 2006.

[5] Ministry of Health. 2015. Nutrient Reference Values. [ONLINE] Available at: http://www.nrv.gov.au/nutrients.

[6]NUTTAB 2010 Online Searchable Database, Food Standards Australia New Zealand [ONLINE] Available at: http://www.foodstandards.gov.au/science/monitoringnutrients/nutrientables/nuttab/Pages/default.aspx

[7] Physicians Committee for Responsible Medicine. 2015. Soy and Health. [ONLINE] Available at: http://www.pcrm.org/sites/default/files/pdfs/health/pv_soy_and_your_health.pdf.

[8] Academy of Nutrition and Dietetics. 2014. Zinc in Vegetarian diets. [ONLINE] Available at: http://vegetariannutrition.net/docs/Zinc-Vegetarian-Nutrition.pdf.

[9] Tucker, K. et al, 2000. Plasma vitamin B-12 concentrations relate to intake source in the Framingham Offspring Study1,2,3. The American Journal of Clinical Nutrition, [Online]. 71, 514-522. Available at: http://ajcn.nutrition.org/content/71/2/514.full.