Health benefits and meeting nutritional needs on a vegetarian diet
Kate Marsh is an Accredited Practicing Dietitian and Credentialled Diabetes Educator in Sydney with a particular interest in vegetarian nutrition. In this article Kate explains the health benefits of a vegetarian diet and looks at how to obtain specific nutrients commonly obtained through meat and dairy food.
A vegetarian is someone who consumes a diet consisting mostly of plant-based foods including fruit, vegetables, nuts, seeds and grains. Some (lacto-ovo vegetarians) also consume eggs and dairy products. Vegans don’t eat any animal products.
There are many different reasons why someone might choose to follow a vegetarian diet including for health benefits, environmental reasons, animal rights, ethical reasons and religion.
Numerous studies have now shown the benefits of a vegetarian or plant-based diet for our health and there are many reasons why this may be the case. In general, vegetarian diets:
It is likely that the combination of these factors, as well as the avoidance of red meat (which has been linked with a higher risk of diseases like cancer and type 2 diabetes) provide vegetarians with an advantage when it comes to their health. In fact vegetarians are less likely to develop type obesity, 2 diabetes, heart disease, high blood pressure and some types of cancer. Some studies have shown they are even more likely to live longer.
If you have thought about changing to a vegetarian diet, or have already made the switch, but are worried about getting all the nutrition you need, the good news is that a well-planned vegetarian diet can certainly meet your nutritional needs. However there are some nutrients that may need special attention.
Protein is an essential nutrient that is required for many vital roles in the body. Proteins are made up of amino acids – some of these can be made by the body while others (known as “essential” amino acids) must be supplied by the diet. As a vegetarian you can obtain of all the essential amino acids you need by eating a variety of different types of plant foods including legumes, grains, nuts & seeds and soy products. It was once thought that certain combinations of plant foods had to be eaten at the same meal but it is now known that strict protein combining is not necessary.
Tips for meeting your protein needs:
Ø Use legumes such as chickpeas, lentils, and canned or dried beans regularly in your meals
Ø Choose wholegrains such as brown rice, buckwheat, quinoa and amaranth
Ø Include dairy or soy products regularly including milk, yoghurt, soy milk and tofu
Ø Incorporate nuts and seeds in your diet most days
Iron is an essential mineral which plays a vital role in forming haemoglobin, which transports oxygen around the body, and assisting in energy-producing chemical reactions and maintaining a healthy immune system. Low iron levels lead to anaemia. There are two types of iron in food - haem iron is found in animal foods while non-haem iron is found in eggs and plant foods such as legumes, cereal grains, nuts, seeds and dark green leafy vegetables. Non-haem iron is not as well absorbed by the body but including foods high in vitamin C at the same meal can improve absorption. Tea and coffee can inhibit the absorption of iron.
Tips for meeting your iron needs:
Ø Eat legumes, tofu, dark green leafy vegetables, nuts, seeds and wholegrains regularly
Ø Include a vitamin C-rich fruit or vegetable at each meal
Ø Limit your intake of tea and coffee to between meals rather than with meals
Zinc is needed for reproduction, growth, wound healing, sexual maturation and for maintaining a healthy immune system. While it is found widely in plant foods, its absorption is reduced by phytates found in wheat bran, wholegrains and legumes. Processing a food by soaking, fermenting or sprouting can reduce the phytate level and make zinc more readily available.
Tips for meeting your zinc needs:
Ø Eat legumes, tofu, tempeh, nuts, seeds, and wholegrains regularly
Ø Use sprouted legumes (eg mung beans) in salads and sandwiches
Calcium is important for healthy bones and teeth and also plays a role in muscle contraction and relaxation, blood clotting, nerve function and regulation of blood pressure. For lacto-ovo vegetarians, dairy products provide plenty of calcium. Vegans can obtain their calcium from fortified soy milk or other plant foods rich in calcium. Calcium absorption is improved in the presence of vitamin D but is reduced by sodium and caffeine.
Tips for meeting your calcium needs:
Ø Consume calcium-rich foods daily including dairy products or calcium-fortified products
Ø Include other plant-based sources of calcium regularly such as hard tofu, almonds, unhulled tahini, dried figs, kale, broccoli and Asian greens.
Ø Limit your salt intake
Ø Limit caffeine found in tea, coffee, cola and ‘energy’ drinks
Ø Make sure that you get enough vitamin D from sensible sunlight exposure
Vitamin B12 is an essential vitamin which is found almost exclusively in animal foods. We need it to form red blood cells and to maintain a healthy nervous system. Deficiency can cause a type of anaemia and may lead to irreversible nerve damage. It is particularly important for women who are pregnant or breastfeeding as newborn babies have very little of their own stores and rely on obtaining vitamin B12 from their mothers breastmilk. Vitamin B12 is found in red meat, poultry, seafood, milk, yoghurt, eggs and cheese. Plant foods are not a reliable source of this vitamin and some plant foods promoted as containing vitamin B12 (such as tempeh and miso) contain an inactive form of B12, which interferes with the normal absorption and metabolism of the active form in the body and will not prevent a deficiency.
Tips for meeting your vitamin B12 needs:
Ø If you eat them, include dairy products and eggs in your diet regularly
Ø If you follow a vegan diet, choose soy milk fortified with vitamin B12. Some vegetarian burgers, sausages and yeast extracts are also fortified with vitamin B12.
Ø If you don’t eat foods containing vitamin B12, take a B12 supplement
Useful Links and references
Dr Kate Marsh
PhD, M Nutr Diet, BSc, Grad Cert Diab Edn & Mgt
Advanced Accredited Practicing Dietitian (AdvAPD)
Credentialled Diabetes Educator (CDE)
Kate Marsh is an Accredited Practicing Dietitian and Credentialled Diabetes Educator in Sydney with a particular interest in vegetarian nutrition. She is the co-author of The Low GI Vegetarian Cookbook with Prof Jennie Brand Miller, Kaye Foster-Powell and Philippa Sandall.