Whether you are deciding to go vegetarian for ethical, personal or health reasons there are a few principles that are essential to wellbeing with this dietary choice. A vegetarian lifestyle can be very healthy when abundant in the necessary foods for health. However, if not managed well it can lack many essential nutrients and cause deficiencies and health problems. Here we cover some important things to be aware of if wanting to transition to a plant based diet.
Forms of iron
There are two forms of iron, haeme and non-haeme iron. Haeme iron is derived from haemoglobin and myoglobin from animal based foods, whereas non-haeme iron is found in mostly plant foods and a smaller amount in animal products. Haeme iron is more easily absorbed because of the form it is in. It also is less likely to be impacted by factors that enhance or decrease the absorption of iron.
Getting enough non-haeme iron can be a little more challenging as it depends on absorption enhancers, inhibitors, enzymes, gut health and the overall iron status. Common inhibitors of iron absorption include phytates, polyphenols (tea, coffee, wine, some legumes, fruit and vegetables) and calcium. Common enhancers of iron absorption include vitamin c and muscle tissue (such as through animal products). Inflammation may also play a role in iron metabolism. Iron in both haeme and non-haeme form is important for healthy red blood cells (that transport oxygen around the body).
With a whole food plant based vegetarian diet it is usually difficult to become protein deficient. However there are some measures that can be used to optimise protein intake.
Protein is made up of amino acids which are essential for health. Animal products have a complete amino acid profile (including eggs), whereas plant-based sources of protein have incomplete protein sources (with the exception of tofu). This means to achieve a complete amino acid profile, foods are best combined. For instance, combining any legume with nuts/seeds or with grains will give you the full amino acid profile. Meals conscious of protein combining include lentil dhal with basmati rice or vegetable sticks with hommus and tahini.
Estrogen, Soy & Legumes
Estrogen is a reproductive hormone that is largely present in women, however also found in small quantities in men.
Soy, tempeh, miso, tofu, natto and legumes (including lentils, beans, chickpeas) contain a substance called isoflavones. Isoflavones are considered a phytoestrogen which is a substance that is found in plants to be very similar to human oestrogen. Isoflavones are also able to affect the receptors responsible for oestrogens in the body. This is why soy can have estrogen like effects.
There are two known binding sites for oestrogen; estrogen receptor alpha and estrogen receptor beta. The isoflavones will generally favour estrogen receptor beta which can cause a variety of responses that vary per individual based on gut health, hormonal health, liver, detox functions, genetics and lifestyle. This means for some it can work as anti-oestrogenic, and others it may have no effect or a negative effect. It is important to note that isoflavones exert a weaker effect on estrogen receptors than the actual form of oestrogen. However for the wrong person it can be unsuitable.
Situations where isoflavones may be inappropriate include with oestrogen dominance where there is a natural tendency for the body to have excess oestrogen such as endometriosis, polycystic ovaries, hormonal cancers, certain medications such as the oral contraceptive pill and hormone replacement therapy, autoimmune disease, inflammatory disorders, candida overgrowth, fungal conditions, chronic stress, heavy metal toxicity, excess weight and thyroid disorders.
Saponins, Anti-Nutrients & Autoimmune Conditions
Saponins are phytochemicals that create a soap like foam when combined with water. They are found in beans, peas, soybeans and legumes. Saponins can be beneficial or detrimental in different circumstances and may be classed as ‘anti-nutrients’. This is alongside other substances such as tannins, phytic acid/phytates, glucosinolates, lectins and oxalates. Anti-nutrients are substances the plant produces as a defence mechanism against infection, invasion or being eaten. For the wrong people, consuming foods high in anti-nutrients have the potential to decrease the absorption of nutrients and may contribute to immune dysregulation (autoimmune disorders), inflammation as well as gastrointestinal hyperpermeability (leaky gut).
This is where it is important to get a personalized treatment program and professional guidance to find which foods are most suitable for you.
Some general guidelines for plant based eating include:
Maintain a wholefood, plant-based diet (whole veggies, fruit, grains), rather than “junk food” vegetarian (pizza, chips etc).
Approximately 5 or more cups vegetables per day, 2-3 serves fruit, 3-4 serves of wholegrains, 3 serves of ‘healthy’ fatty foods (i.e. 1/3 avocado, small handful (30g) nuts/seeds) 1-3 serves of legumes/beans/tofu/nuts/seeds (Note: nuts and seeds fall into 2 categories as they fall within both ‘fat and protein’
Flaxseed, chia or hemp seeds 1-2tbsp day (omega 3)
Brazil nuts (1-2/day- selenium)
For wellbeing on a vegetarian diet, it does require more effort and planning. Nutrients to monitor include:
Iron: non-haeme (vegetarian form of iron) is different to haeme iron (found in animal products). Sources of non-haeme iron include; green leafy vegetables, tomato paste, dhal, baked beans, almonds, sesame seeds, walnuts, pecans, lentils, black rice.
To help iron absorption it is important to combine plant sources of iron with foods that contain vitamin C(including lemon, lime, chilli, strawberries, tomato, broccoli, red capsicum, mango). Also avoid tea or coffee with meals as it can interfere with iron absorption.
Note: This is an example nutrient spread- however not all of this may be achieved in one day. Look at nutrient intake WEEKLY as opposed to daily to ensure enough nutrients are consumed.
Roasted sweet potato with lentils, avocado, cucumber, tomato, with lemon and hemp dressing
Cooked brown rice, blackbeans, roasted pumpkin, tempeh, broccoli, kale, tahini and lemon dressing.
Lentil dhal, lentil stew
Homemade veggie pizza
Vegetable and tofu stir fry with sesame seeds
Snacks; fruit, corn chips, popcorn, trail mix, protein balls, raw veggies, chia pudding, PANA chocolate, loving earth chocolate (not daily!!).
Disclaimer: each individual has their own dietary requirements and needs and as such may vary from the recommendations above. Please chat to your healthcare practitioner about individualising a program suitable for you.
Davis, B. C. & Kris-Etherton, P. M. (2003). Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications. Am J Clin Nutr, 78(Suppl 3), 640S-646S. Retrieved from http:// ajcn.nutri on.org/content/78/3/640S.long
Harvard Women’s Health Watch (2016). Becoming a vegetarian. Retrieved from h p://www.health.harvard.edu/ staying-healthy/becoming-a-vegetarian
Hechtman, L. (2012). Clinical Naturopathic Medicine. Chatswood, NSW: Churchill Livingstone.
Mangels, A. R. (2014). Bone nutrients for vegetarians. Am J Clin Nutr, 100(Suppl 1), 469S-475S. doi: 10.3945/ ajcn.113.071423
Marsh, K., Zeuschner, C., Saunders, A. & Reid, M. (2009). nutritional needs on a vegetarian diet. Australian Family Physician, 38(8), 600-602. Retrieved from http://www.racgp.org.au/download/Documents/AFP/2009/ August/200908marsh.pdf
Utah Department of Health (2011). Protein. Retrieved from http://health.utah.gov/wic/pdf/ forms_and_modules/Sta _Training_Modules/Basic%20Nutri on/basic%20nutri on%20module%205.11_ les/ Page322.htm
West, A.R., & Oates, P.S. (2008). Mechanisms of heme iron absorption: Current questions and controversies. World J Gastroenterol. 14(26): 4101-4110. Doi: 103748/wjg.14.4101
Patel, S., Homaei, A., Raju, A.B., & Meher, B.R. (2018). Estrogen: The necessary evil for human health, and ways to tame it. Biomed & Pharma, (102), 403-411. http://doi.org/10.1016/j.biopha.2018.03.078
Shi, J., Arunasalam, K., Yeung, D., Kakuda, Y., Mittal, G., & Jiang, Y. (2004). Saponins from edible legumes: chemistry, processing, and health benefits. J Med Food. 7(1), 67-78. https://www.ncbi.nlm.nih.gov/pubmed/15117556
Chan, T.H. Harvard. The Nutrition Source. Are anti-nutrients harmful? https://www.hsph.harvard.edu/nutritionsource/anti-nutrients/