Vegan lifestyles are growing in popularity. Dietitian Nicole Dynan looks at how patients can best maintain nutrition when favouring a plant-based diet.

 

Vegan diets are now considered more mainstream, but most people choosing to become vegan will need some advice on planning their diet to ensure they meet their nutrient needs. Calcium, protein, zinc, vitamin D, iodine and essential fats can all be obtained through plant foods with a little planning.

A recent poll revealed that 11.2% Australians, around 2.6 million people are favouring a plant-based diet, with evidence the numbers are growing [1]. Australia is now the third-fastest growing vegan market in the world, after the United Arab Emirates and China [2]. Australia’s packaged vegan food market is valued at $136 million, with predictions that will reach $215 million by 2020.

The general increase in interest in veganism could be for any number of reasons, including concerns for animal welfare, health improvements, weight management or the desire for a more environmentally friendly lifestyle.

Benefits of going meat-free
Plants form the dietary foundation of some of the best diets in the world. They are linked with lower levels of chronic disease such as diabetes, obesity, heart disease and some cancers [3]. A key benefit is that plants are rich in many nutrients, providing more fibre, folate, thiamine, magnesium, and vitamins A, C and E [4]. However, it should not be assumed that a vegan diet is automatically healthier. A purely plant-based diet can be balanced, just like a diet containing meat, but only if it is planned well.

Vegans needed to work hard to ensure that ‘nutrients at risk’, like protein, zinc, iron, omega 3, calcium and B12 are in their foods. Opting for fortified drinks and foods, such as soy drinks with added calcium, can help. According to The Australian Dietary Guidelines, ‘appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthy and nutritionally adequate’ [5].

Nutrients at risk on a vegan or vegetarian diet [6]
Some specific nutrients are more easily absorbed from, and only found in, animal products. When following a vegan diet, it is therefore important to be aware of these nutrients to decrease the risk of deficiency.

Vegan diets need to contain adequate amounts of legumes and fortified dairy alternatives to ensure they are meeting requirements for protein, zinc, iron, omega 3, calcium, vitamin B12 and vitamin D, as these are readily available in meat, fish, poultry and dairy foods.

Those following a vegan diet may need to take a vitamin B12 supplement or vitamin B12 fortified foods to ensure they are meeting requirements for this vitamin, as it is only found naturally in animal products.

 

Iron
Iron an be found in animal sources and plant-based sources. Animal sources of iron (eg meat products, fish and offal) are known as haem iron, which is most easily absorbed by the body. Non-haem iron is found in eggs and plant foods and is not as easily absorbed by the body.It is recommended that adults following a vegan or vegetarian diet aim for 1.8 times the recommended daily intake for iron, ie 32 mg (women) 14 mg (men) aged 19–50 years [7]. Plant-based iron sources include legumes, tofu, tempeh, leafy green vegetables, iron-fortified cereals, and nuts and seeds. Including foods high in vitamin C (eg citrus foods) with plant-based sources of iron can help boost uptake of this nutrient.

Vitamin B12
Vitamin B12 is essential for healthy blood cells and neurological function. It is only found naturally in animal products; therefore, it is recommended to consume vitamin B12-fortified foods (eg soy products, meat substitutes, etc) or consider a vitamin B12 supplement.

Calcium
As a vegan diet does not include dairy products, it is important to include other calcium-rich foods, as this is beneficial for strong bones, teeth and muscle function. Including calcium-fortified foods, tahini, nuts and seeds, and leafy green vegetables can help boost intake. Having adequate vitamin D (obtained either from the sun or through vitamin D-fortified foods (eg margarine and some soy milks), helps to increase absorption of calcium.

Zinc
Zinc provides many benefits, particularly with wound-healing, healthy skin and the immune system. Plant-based sources of zinc include legumes, grains, nuts, seeds and soy foods (eg tofu, soy milk and soy yoghurt).

Omega 3
Omega 3 provides many health benefits, including protection against heart disease. The body cannot produce omega 3, so it is best to be gained through plant sources such as flaxseeds, walnuts, seaweed, tofu and omega 3-fortified soy milks.

Children on vegan or vegetarian diets [8]
Special care should be taken with children on vegetarian diets and, especially, vegan diets. There are several things to consider if a child is vegetarian or vegan.

Children have high energy needs and small stomachs, so they need regular meals and snacks. Including a good variety and combination of refined and unrefined cereal products will help them get the energy they need.

It is important to watch the amount of fibre in a child’s diet. Too much can lead to poor absorption of important minerals such as iron, zinc and calcium. It can also be very filling, preventing a child from eating enough food.

Vitamin C enhances the absorption of iron. Include foods rich in vitamin C with foods rich in iron, eg an orange with baked beans on toast.

Combining legumes and grains can ensure children obtain a ‘complete protein’, with all amino acids for growth and development

 

Tips to help plan a vegan diet
1. Include at least three serves of legumes each day 
These could include scrambled tofu, bean burrito bowls, hummus dips or wraps, vegetarian burgers and soy milk.

2. Eat good sources of vitamin C with meals and snacks to boost iron absorption 
These could include citrus fruits, tomatoes, capsicum, strawberries and leafy green vegetables. Meals could include lentil soup with spinach and tomatoes, or porridge with strawberries.

3. Include sources of calcium in meals 
Calcium-rich foods can be found in all vegan food groups, including as fortified rice, almond or soy milks and yoghurts, tofu and tempeh, leafy green vegetables (eg kale and bok choy), and other plant foods (eg Lebanese cucumbers, broccoli, oranges and dried figs).

4. Include a daily serve of healthy fats 
This can be done with, for example, one teaspoon of flaxseed oil or olive oil, 30 g or ¼ cup of nuts and/or seeds or ¼ avocado.

5. Choose foods that enhance iron and zinc absorption 
Phytates (antioxidants) in grains, legumes, nuts and seeds can slow the absorption of minerals in foods. Choosing wholegrain breads made with yeast or sourdough, toasted nuts and seeds and sprouted grains and legumes can help ensure good absorption of iron and zinc.

6. Take supplements where needed 
Vitamin B12 is only found in animal products, but can be obtained through some fortified plant-based foods. Supplements are often prescribed to helps people on a vegan diet meet the needs of this vitamin as it is important for many functions in the body. Other nutrients that may require supplementation if dietary planning is inadequate include iodine, vitamin D, omega-3, iron and zinc

Bottom line
Vegan diets can be healthy or unhealthy, depending on how well they are planned.

Increasing plants in any diet can help can convey health benefits by making it more likely that nutrient needs are met.

 

This article was originally published on RACGP and has been adapted for dietitians