Question: Is the fluoride added to water supplies safe?
Mineral salts in rocks, soils, some plants and animals, and some natural waters contain fluoride. Most Australia water supplies have added fluoride at levels proven to reduce tooth decay. This process began in the 1950s and increased rapidly during the 1960s and 1970s. The National Health and Medical Research Council (NHMRC) controls and monitors the scheme. Their continuing research – and that of many qualified experts – shows it’s a safe, cost-effective and protective strategy to strengthen tooth enamel and help repair the early stages of damage caused by many foods and drinks.
Because of its role in dental health, fluoride is now considered an essential nutrient. Like all nutrients, it has an upper limit of safety, currently 10mg/day, with the upper limit set lower for children under nine years of age.
Most toothpastes also contain fluoride, and the combination with fluoridated water offers better dental protection than either one alone. In Australia, some children have developed mild dental fluorosis which causes white lines to form on teeth. This occurs before the teeth have erupted and is due to toothpaste, not water supplies. Low fluoride toothpaste should be used for children, and only then in small quantities for those under six years of age, as they often swallow the paste.
Fluoride isn’t the only factor involved in tooth decay – diet is also important. The worst aspects of diet are sugary foods like lollies, bars, cakes, biscuits, sugared breakfast cereals, soft drinks (including those that are artificially sweetened and especially cola), lemon juice and any refined carbohydrates such as savoury biscuits or crisps.
Some bottled waters contain naturally occurring fluoride, but most bottled water is simply regular water that has been filtered. The filtering used removes the fluoride, although some brands add it back at permitted levels of 0.6-1mg/L.
Foods that contain small quantities of natural fluoride include tea leaves, some grains, almonds, apples, beef, chocolate and milk.
Some users of tank water ask if they should add fluoride to their water tanks. That is not advised as it would be difficult to add exactly the right amount, especially as water levels vary according to rain patterns. Ask your dentist whether fluoride tablets should be used.
Some people are against adding fluoride to water supplies. It is always ‘the dose that makes the poison’, and you’d have to drink more than 10L of fluoridated water every day to reach the upper limit. The NHMRC addresses claims in a series of Questions and Answers on Water Fluoridation and Human Health on their website https://www.nhmrc.gov.au/fluoridation.
Verdict: Yes, the level of fluoridation in Australian water is safe.
Question: Can vegetarians and vegans get enough protein and iron?
Meat is an excellent source of both protein and iron but is not the only source. Vegetarians who include cheese, yoghurt, milk and eggs have no problems getting enough protein. Vegans can also easily meet the body’s needs as all types of legumes (chick peas, lentils and beans), quinoa and nuts are top sources and grains – especially oats and seeds – add more.
For iron, the haem iron in meat is absorbed better than the non-haem iron in legumes, grains, vegetables and eggs. However, these foods can supply ample quantities of iron for most people, although parents of young children following a vegan diet need to ensure children eat enough plant sources of iron.
In Australia, studies show low iron levels are no more common in vegetarians than in meat eaters. Low iron levels in females are usually due to heavy periods. Low levels in men may indicate bleeding in some part of the intestine and should always be checked.
Check that growing teenage girls who follow a vegetarian or vegan diet actually consume enough of the plant sources of iron. Eating disorders can also result in low levels of iron as well as other minerals and vitamins.
If an iron supplement is needed and leads to side effects such as tummy problems or diarrhoea, just as much iron can be absorbed by taking an iron tablet only every second or third day.
While low iron levels need to be checked, high levels are also problematic.
Verdict: Vegetarians and vegans can get plenty of protein and iron from plant-based foods, but girls and women with heavy periods may need an iron supplement.
Question: Should we all minimise gluten?
Gluten is one of the proteins found in wheat, rye, barley, and triticale (a hybrid grain developed from rye and wheat).
Anyone who has been diagnosed by a gastroenterologist as having coeliac disease (an auto-immune disease, not an allergy) must avoid all gluten for life. This also includes avoiding older varieties of wheat such as spelt, emmer, kamut and eikhorn, as they all contain gluten. About 8% of people with coeliac disease also react to a protein called avenin in oats. This unfortunately means they must avoid oats unless they come from a factory that doesn’t process grains containing gluten.
Studies show coeliac disease occurs in 1%-2% of the population, way below popular belief.
Other possible problems may include an allergy to wheat or a low tolerance of FODMAPS (Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols).
These compounds are found not only in wheat and rye but also in many other foods including apple juice, mushrooms, cashews, some fruits and vegetables, lactose in milk, and some food additives. A high intake of FOPDMAPS can be a cause of irritable bowel syndrome and symptoms may be reduced by lowering the intake of FODMAPS, not just wheat.
Verdict: A small number of people need to avoid gluten, but the majority of the population can enjoy the excellent nutrients and valuable types of dietary fibre in wholegrain products. Alternative options for those diagnosed with coeliac disease include brown rice, millet, amaranth, corn, chickpea flour, buckwheat, sorghum, teff and quinoa.
Question: Should we take fish oil supplements?
Fish and all types of seafood contain valuable omega 3 fatty acids. There’s a whole family of these unsaturated fats, so it’s as silly to refer to them as ‘omega 3’ as it would be to talk about ‘vitamin’.
Sea creatures and some seaweeds use marine algae to make two valuable omega 3 fats, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Plants contain the omega 3 fatty acid, alpha-linolenic acid (ALA). Top sources include linseeds (also called flaxseeds), chia, canola, walnuts, edamame and hemp. Green vegetables, especially brussel sprouts, also contain some ALA.
All omega 3 fatty acids go rancid quickly, including those in supplements. Most people recognise the smell of ‘off’ seafood, but may not recognise when the omega 3 fats in foods rich in ALA are ‘off’.
Linseeds are so rich in ALA that it’s very difficult to extract their oil without it oxidising. It’s best kept for use on cricket bats and in paints. Linseeds themselves are fine as their tough coat can protect the ALA from oxidation. If ground, they should be fresh and kept in the fridge.
Linseeds are not broken down in the small intestine like most foods. However, when they reach the large intestine, they cling to the lining and gradually release their valuable fatty acid as food for healthy microbes.
Canola oil should also be kept cool. Avoid stale walnuts.
Supplements have been widely promoted, with some studies (usually funded by supplement sellers) showing value while other long term studies show little or no value.
Verdict: My preference is to choose real foods whenever possible.
Dr Rosemary Stanton OAM