Latest Fact Sheet

Season 4, Ep 7 - Soy

·Over 200 million tonnes of soybeans are grown worldwide every year.

·In New Zealand, our main sources of soybeans are Canada, India, China and Australia.Last year we imported over a million kilos of soybeans alone.We also import soy in the form of soy flour and soy meal, soy sauce, soy milk, and food ingredients such as textured vegetable protein.

·A raw soybean is made up of approximately 20% fat, 30% carbohydrate and 36% protein.

·Soy ingredients are used in many foods in the forms of soy flour, soy protein, textured vegetable protein, the emulsifier soy lecithin, hydrolysed vegetable protein, sterols in cholesterol-lowering table spreads and vitamin E as an antioxidant.

·Soy contains plant estrogens called phytoestrogens which can act like the estrogen made in our bodies. Soy phytoestrogens could have benefits for bone health, post-menopausal hormone levels and certain cancers.But there is concern that phytoestrogens could affect fertility and development and much more research is needed to confirm the potential benefits and impacts of phytoestrogens.

·It’s difficult to calculate, but scientists have estimated the foods that contribute the most genistein (a phytoestrogen) from soy to a New Zealand adult’s diet are bread, soy milk and sausages.

·Phytates are found in many plant foods, including soy, and they can reduce our uptake of essential minerals like iron, zinc and calcium.People who have a diet low in minerals, such as vegans, should be careful about the amount of soy they consume for this reason, but this shouldn’t be a problem for people who eat a mixed diet with plenty of minerals.

·Enzyme inhibitors in soy can interfere with the enzymes that help us digest food.However we don’t need to be concerned about enzyme inhibitors in soy foods because they are mainly destroyed in the heat processing of soybeans and most of the soy products we eat, such as soy milk and tofu, have been heat-treated.

·The Ministry of Agriculture and Fisheries recently tested a total of 189 soy sauce samples for contamination with the chloropropanols 3-MCPD and 1,3-DCP and they found two samples above limits.

·A standard ingredient in soy sauce is sodium.We compared the amount of sodium in soy sauce products and found that just a tablespoon of one product contains half an adult’s recommended maximum daily intake for sodium.

·Soy is a good source of protein and it’s the only vegetable protein described as complete.This means it contains all the essential amino acids which our bodies can’t make so we have to get them from food.

·Soy protein has been shown to decrease cholesterol by 3%, but you need to substitute 50g of animal protein with 50g of soy protein every day to get this effect.This is the same as replacing 150g of steak and 1 cup of blue top milk with 200g of tofu, 2 cups of soy milk and 150g of edamame.

·Compared to animal products, tofu has less protein but much less saturated fat.For example, 100g of tofu has 8g of protein and just 0.7g of saturated fat, whereas 100g of stewed lean lamb chop has 28g of protein and 6.7g of saturated fat.

·Soy milk can be a good option for people who are lactose intolerant as it can be a good source of calcium, but if you’re drinking soy milk for the calcium, it pays to compare products as the amount of calcium varies from none to 400mg per cup.

·Nearly 60% of the world’s soy crop is now grown from genetically modified plants.In Argentina, 98% of the soy crop is genetically modified. Last year New Zealand imported 7 million kg of soy flour and meal from Argentina, some of which is used for animal feed.

·In New Zealand, food must be labelled as genetically modified if it contains GM DNA or protein, or altered characteristics from the genetic modification.However, foods that don’t fit these requirements, and some flavours, don’t have to be labelled.

·We tested 5 samples of tofu and 5 samples of soy milk for pesticide residues and we found none.

Read more about Soy via these links.