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Pindara Private Hospital Magazine - Issue Eight

POLYPHENOLS Polyphenols are a group of antioxidants that are abundant in foods and have been associated with improvements in various diseases including cardiovascular, neurodegenerative, diabetes and cancers. For example, several studies have reported that regular intake of dark chocolate that contains high levels of polyphenols improves the functioning of the lining of blood vessels (endothelium) so that blood vessels can open up (vasodilate) better. So, polyphenols are micronutrients that we want in our diet, but unfortunately they bind to iron and reduce iron absorption. Depending on their structure, polyphenols are grouped into the phenolic acids (including tannins), flavonoids, stilbenes and lignans. These micronutrients are found in black and green tea, coffee, red wine, berries, plums, apples, pears, potatoes, wheat, rice, corn, capsicums, tomatoes, dry legumes (soya beans), tofu, beans, cherries, grapes, citrus and chocolate. Foods that enhance iron absorption ASCORBIC ACID (VITAMIN C) Vitamin C is a powerful enhancer of iron absorption. Foods that are rich in vitamin C (in descending order) are limes, basil, seaweed, guava, chilli, red capsicum, parsley, lemon, broccoli, brussels sprouts, kiwi fruit, watercress, green capsicum, orange juice, cauliflower, red cabbage, dill, pawpaw, orange, kale, mandarin, snow pea, lychee, coriander, strawberries, white cabbage, spring onion, rockmelon, spinach, leek, sweet potato, spices (cloves, coriander seed, cumin seed, nutmeg, thyme, turmeric, allspice, cinnamon), zucchini, feijoa, plum, broad beans, tomato, mango and chicken liver. Cooking, processing and storage can lead to the degradation of vitamin C in foods. MUSCLE TISSUE The presence of meat, fish or chicken in a meal can increase the iron absorbed from vegetables/plant sources (non-heme iron) by two to three-fold. Thirty grams of muscle tissue has the same effect as 25 milligrams of ascorbic acid. The role of the garden in your gut Our gastrointestinal tract, particularly our colon, is home to trillions of microbes. This gut microbiota is a mix of bacteria, viruses and protozoa. Although most iron is absorbed in the duodenum, iron absorption proteins are present in the colon and it appears that healthy gut bacteria can improve the absorption of iron that occurs here. One can improve the quality and quantity of one’s gut bacteria with both pre and probiotics. Prebiotics are the foods needed for gut flora to thrive and probiotics are supplies of good bacteria. Examples are kombucha, sauerkraut and Inner Health Plus supplements. In summary, animal sources of iron are absorbed with the least interference, and livers are the best animal source. Calcium interferes with the absorption of all iron so it makes sense to eat separate calcium-rich meals (with milk, cheese and yoghurt) and iron-rich meals that don’t contain high levels of calcium. There are many plant foods with excellent iron content. A non-heme iron-rich meal would need to be free of dairy (other than butter and cream), eggs, soya and low in polyphenols. Phytates would need to be reduced, for example by activating seeds and nuts. One would include vitamin C rich foods and some meat, fish or chicken to improve the iron absorption. Lastly, tend to “the garden in your gut”. Blood loss For many women, iron deficiency is caused by heavy periods (menorrhagia) and this requires treatment by a gynaecologist. When there is no clear cause for iron deficiency, then bleeding from the gastrointestinal tract requires exclusion with a gastroscopy and colonoscopy. How do we test for iron deficiency? The best marker of iron stores is the ferritin level. A level less than 30 mcg/L is consistent with iron deficiency. But if one is about to lose blood, for example during major surgery, then a ferritin of greater than 100 mcg/L is required to enable the bone marrow to produce adequate red blood cells to recover. Ferritin does rise due to infection, inflammation or obesity (independently of the iron present). In these situations iron deficiency may still be present despite having ferritin of greater than 100 mcg/ so the transferrin saturation and/or the soluble transferrin receptor levels are required to determine if iron stores are low. How do we treat iron deficiency? Oral iron can be an effective treatment but many people experience gastrointestinal side effects including nausea and constipation or diarrhoea. In pregnancy, once a woman is iron deficient it is not possible to correct the deficiency with diet alone. The dose of oral iron required to treat iron deficiency is 65 milligrams of elemental iron daily and 100 – 200 milligrams elemental iron daily is required once anaemia has developed. Enteric coated and sustained release preparations are often better tolerated but are less effective as they carry most of the iron past the duodenum where it is predominantly absorbed. Liquid iron is also better tolerated but this is because of the small amount of elemental iron present. The alternative is intravenous iron. For many people, this treatment is the difference between struggling through every day and functioning at full speed again. It is particularly indicated for those who are intolerant to oral iron, have poor absorption, for those who have such significant blood loss that oral and dietary iron alone cannot keep up with their requirements (for example very heavy periods), or for those who need to have a rapid rise in their haemoglobin and/or iron stores due to severe symptoms or imminent surgery or delivery. When compared to oral iron, intravenous preparations improve the haemoglobin levels faster and replenish the iron stores better. Ferric carboxymaltose (Ferinject) can be given as a single, rapid (less than 15 minutes) intravenous infusion. Disease states that benefit from iron therapy There are several conditions in which it has recently been recognised that iron deficiency plays a key role. In people with heart failure it has been shown that iron deficiency, with or without anaemia, is associated with lower exercise tolerance, poorer quality of life, more time in hospital and, most significantly, higher rates of death (mortality). Notably, in these studies iron deficiency was defined as a ferritin of less than 100 mcg/L or a transferrin saturation of less than 20%. Unfortunately it has been shown that in those with heart failure, iron absorption from oral iron is often poor and gastrointestinal side effects are common. Treatment with intravenous iron has been shown to improve symptoms and exercise tolerance (NYHA functional class) and reduces hospitalisation. People with diseases of the gastrointestinal tract that reduce the ability for the gut to absorb iron, such as Coeliac Disease or inflammatory bowel disease, as well as those who have had gut resections or gastric bypass surgery, can benefit greatly from IV iron therapy. Other diseases in which anaemia is prevalent and has been shown to be associated with poorer outcomes are renal failure, intracerebral hemorrhage, chronic obstructive pulmonary disease, acute coronary syndrome and people undergoing cardiothoracic surgery. Anaemia that is present prior to surgery is associated with higher rates of complications and even death. Several guidelines recommend treatment of iron deficiency prior to surgery if the expectation is that blood loss will exceed 1,200 millilitres. Treatment is offered if ferritin levels are less than 100mcg/L or transferrin saturations is less than 20%. pindaramagazine.com.au Pindara Magazine 45


Pindara Private Hospital Magazine - Issue Eight
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