Most people do not have a problem with eating foods containing iron. Iron is needed to make oxygen-carrying proteins such as haemoglobin and myoglobin. However, a condition known as hemochromatosis can interfere with the body's ability to control the amount of iron absorbed, and the results include too much iron in body organs. That can cause iron poisoning resulting in fatigue, anorexia, dizziness, nausea, shortness of breath, and other effects. To avoid iron overload, patients with hemochromatosis must modify their diet by either consuming foods with no or little iron, or by eating foods that prevent iron absorption.
There are two kinds of iron: heme iron, found mostly in meats, and non-heme iron, found in plants and supplements. Heme iron is readily absorbed, whereas non-heme iron is not. It follows that avoiding red meats and foods rich in iron such as beef, lamb, pork, shellfish, salmon, tuna, iron-fortified cereals and dried legumes is advisable for those suffering from hemochromatosis. Instead choose foods containing no iron or low iron, such as dairy products. Dairy products also contain calcium, which helps to block heme and non-heme iron absorption. Examples include milk, yoghurt, cheese and eggwhites. Tofu, sardines, salmon and almonds are also rich in calcium.
Fruits and Vegetables
Certain fruits and vegetables contain oxalates, compounds derived from oxalic acid that hinder the absorption of non-heme iron. Examples include spinach, kale, rhubarb, beets and strawberries, and herbs such as oregano, basil and parsley. Not only do they contain non-heme iron, which is not readily absorbed, they are high in fibre, another component that impairs iron absorption.
Foods with Tannins
Tannins are plant polyphenols that act as astringents. They are not compatible with iron, and they act as inhibitors to iron absorption. Tannins are found in black teas, coffee, wine, cocoa, spices and walnuts, and in fruits such as apples, blackberries, raspberries and blueberries. According to the Iron Disorders Institute, certain teas and Swedish cocoa exhibit strong anti-iron absorption, in some cases up to 90 per cent. These foods can exert their iron absorption-inhibiting capabilities for up to two hours after consumption.
Foods with Phytates
Whole grains, legumes, nuts and seeds contain phytates or phytic acids. These antioxidants can bind to certain dietary minerals such as iron, zinc, manganese and calcium and thus hinder iron absorption. Phytates can reduce iron absorption by 50 per cent to 65 per cent, according to the Iron Disorders Institute. Foods with phytates include soybeans, walnuts, almonds, lentils, peas, cereals and whole grains.