Vegetarian Diets are healthy and sustainable

A review published in the Medical Journal of Australia provides evidence that well planned vegetarian diets based on wholegrains, legumes, nuts, seeds, fruits and vegetables can meet the nutritional needs of children and adults. In addition, plant based diets produce lower green house gas emissions making them more environmentally sustainable.

Written by Accredited Practising Dietitians (APDs) with expertise in vegetarian eating, the various papers  review how vegetarian diets can meet protein, iron, vitamin B12, zinc  and omega 3 fatty acid requirements and provide  practical advice for preparing vegetarian meals.

The following points are made:-

• Followers of vegetarian diets are generally less overweight/obese, have lower blood pressure, lower incidence of Type 2 diabetes and are at less risk of heart disease and cancer than non vegetarians.
• Vegetarian diets are higher in fibre, antioxidants and phytochemicals.
• Protein needs are easily met by a well planned vegetarian diet as long as energy requirements are met. Conscious combining of proteins is not necessary as long as protein is from a variety of sources.
• The risk of iron deficiency in vegetarians is not greater than non vegetarians providing a variety of iron food sources are eaten. These include wholegrains, legumes, iron fortified cereals, nuts, seeds, tofu, tempeh. Vitamin C enhances the absorption of iron from plant sources. As the body controls the level of iron absorption, those with lower iron stores absorb more and excrete less. In pregnancy the body adjusts by increasing iron absorption.
• The risk of zinc deficiency in vegetarians is no different to non vegetarians. While intake of zinc is generally lower than non vegetarians the body adapts by absorbing more and retaining it.
• Omega 3 long chain fats such as DHA and EPA can be at risk in vegetarian diets. While these can be obtained from their precurser ALA, the conversion  is not efficient. Supplements derived from microalgae may be needed during pregnancy and lactation, for the elderly and those with chronic diseases.
• Vitamin B12 is found almost exclusively in animal foods and can be at risk in vegetarian diets. Lacto-ovo vegetarians and those vegetarians also eating fish will have adequate vitamin B12. Many vegetarian foods are fortifed with vitamin B12. Followers of vegan diets will require a B12 supplement. Infants born to vegetarian and vegan mothers are at risk of B12 deficiency and will require a B12 supplement. Pregnant and breast feeding vegetarian/vegan mothers will need to make sure they have adequate B12 in their diet to meet theirs and their babies needs.

Further information on Healthy vegetarian eating for infants and young children can be found in a previous HeinzSIght publication.

References.

MJA Open 2012, Suppl 2:5-45

HeinzSIght July 2007, Number 76