Iron Deficiency Prevention Diet
Most of the iron in our bodies is recycled from dead or damaged red blood cells. Small quantities of iron (1-2 mg) are lost by the shedding of skin, GI and urinary tract cells, as well as menstruation. Since our bodies cannot synthesize iron, absorption from food is the only way to make up for the lost iron.
To efficiently increase your iron levels, you should optimize both your iron intake and absorption.
Dietary iron comes in two forms: heme iron, present in meat, poultry and fish; and, non-heme iron, present in both plant and animal sources.
Heme iron from animal sources comes mainly from hemoglobin (a protein in red blood cells that is responsible for oxygen transport) and myoglobin (a protein found in muscle tissue, responsible for supplying muscle cells with oxygen). Heme iron represents only a small fraction of iron intake in omnivore’s diet (about 10%). Good sources of heme iron are various meats: beef and beef liver, sardines, chicken, turkey, oysters, clams, mussels.
Non-heme iron represents about 90% of dietary iron. This form of iron is generally used for iron supplementation
and food fortification. The best plant sources of iron are legumes (lentils, beans, soybeans), dark leafy greens (collard greens, Swiss chard, kale), grains (quinoa, brown rice, oatmeal), nuts (cashews, pistachios), and seeds (pumpkin, sunflower, tahini).
Low meat consumption, in healthy diets such as the Mediterranean diet, or even complete elimination of meat (vegetarian and vegan diets), has no detrimental effect on the intake of iron.
Iron is a unique element in the world of micronutrients. Small daily losses notwithstanding, our bodies lack a mechanism to dispose of it. However, absorption of iron in the gastrointestinal tract is tightly regulated so as to prevent its excessive accumulation. Excess iron produces free radicals that cause oxidative stress involved in many diseases such as atherosclerosis, cancer, and diabetes.
Absorption of dietary iron greatly depends on the type of iron that is consumed. Heme iron from meat is more efficiently absorbed than the non-heme type. However, absorption of non-heme iron is largely determined by our needs. While absorption of heme iron remains within a relatively narrow range regardless of our iron status, absorption of non-heme iron increases when our iron stores are low. In addition, absorption of non-heme iron can be regulated by the use of dietary factors that either enhance or inhibit it. Although it is impossible to predict exactly how much iron will be absorbed from a mixed diet, it is still very useful to know which dietary factors increase or decrease its absorption. Consuming enhancers together with, and inhibitors separately from the iron rich foods, will greatly optimize your iron absorption.
Enhancers of iron absorption
Ascorbic acid (vitamin C). Of all dietary factors that affect iron absorption, vitamin C is the most powerful one. Vitamin C has such a strong effect on iron absorption that it often overrides the negative impact of inhibitors. This enhancing effect of vitamin C is attributed to its influence on iron bioavailability. New research shows that vitamin C plays an active role not only in iron absorption but also in its metabolism.
Vitamin C is abundant in many fruits and vegetables: bell and green peppers, broccoli, Brussels sprouts, cabbage, cauliflower, tomatoes, blackcurrant, oranges, strawberries, kiwi, grapefruit. However, vitamin C is easily degraded by various food preparation methods (cooking, blanching, steaming), industrial processing (canning, freezing, dehydration) and storage. To minimize the loss of vitamin C, you should always cook fresh produce for the shortest time possible, in the minimum amount of water (vitamin C
is water soluble and leaches into cooking water) and using the lowest temperature. Fruits and fruit and vegetable juices are excellent sources of vitamin C, as they are minimally processed and consumed raw.
Muscle tissue. For reasons still unknown, adding muscle tissue from meat, fish, and poultry to a meal increases absorption of non-heme iron. However, improving iron status by increasing amounts of red meat in your diet is far from desirable. Consumption of red meat has been associated with a range of diseases, such as cancer, diabetes, and cardiovascular disease. Varied and well-balanced diets with low red meat consumption provide plenty of iron and at the same time greatly minimize the risk of common diseases (and even increase longevity!). In addition, the incidence of iron deficiency anemia is not higher in vegetarians than in omnivores. This suggests that meat is not necessary to achieve proper iron levels.
Organic Acids. Organic acids such as lactic, tartaric and citric are also enhancers of iron absorption, but their effect is relatively small compared to that of vitamin C. To achieve the same level of iron absorption you would need to consume about 1g of organic acids but only 25mg of vitamin C (40 time difference!). Nonetheless, fruits and vegetables do pack a considerable amount of organic acids, and thus offer yet another way to improve iron absorption.
Citrus fruits are especially well suited to boost iron levels as they contain large amounts of citric acid and vitamin C. One ounce of lemon juice packs about 1.4g of citric acid and 15mg of vitamin C. Lemon juice is an excellent choice for flavoring iron-rich foods like legumes or to make salad dressing.
Raisins and grapes are good sources of tartaric acid, while fermented dairy and pickled vegetables contain a considerable amount of lactic acid.
The only dietary organic acid that has a slight inhibitory impact on iron absorption is oxalic acid. For this reason, consuming foods that are rich in both iron and oxalic acid, such as spinach, will not significantly increase your iron levels.
Inhibitors of iron absorption
Phytic acid (phytate). Found in nuts, legumes, grains and seeds, phytic acid is the primary form of phosphorus storage in these plants. Unfairly dubbed “anti-nutrient factor”(it actually has many health benefits!), phytic acid chelates (binds) iron and prevents its absorption in the gastrointestinal tract. However, the inhibitory effect of phytic acid can be canceled by the use of absorption enhancers such as vitamin C. In addition, such preparation methods as cooking, soaking, sprouting, and fermentation, reduce the amount of phytate in plants. To improve iron absorption, consume phytate-rich foods (almonds, peanuts, Brazil nuts, walnuts, sesame seeds, beans, corn, soybeans, wheat and rice bran) separately (2 hours before or after) from iron-rich foods and iron supplements. To reverse their inhibitory effect, combine phytate-rich foods with foods abundant in vitamin C.
Polyphenols. Similarly to phytic acid, polyphenol compounds can chelate iron and reduce its bioavailability. Polyphenols are a large and diverse group of compounds that are plentiful in fruits and vegetables and are especially abundant in teas, red wine, and coffee. Their effect on iron absorption depends on the amount and the type of polyphenol compounds present in the food. For example, polyphenols from black tea were found to have a higher inhibitory effect on iron absorption than the ones found in herb teas, cocoa, and red wine. It is not advisable to avoid foods with high polyphenolic content as their antioxidant properties are thought to provide protection from chronic diseases such as cancer, cardiovascular disease, and diabetes. To minimize their inhibitory effect, consume polyphenol-rich foods separately from iron-rich foods and iron supplements. Tea and coffee are best taken between meals, not during or shortly after.
Milk and eggs. Proteins from cow milk and egg yolk can bind iron and decrease its absorption (egg white proteins seem to improve iron absorption). To avoid the inhibitory effect of cow milk, substitute it with an alternative such as almond or cashew milk. Calcium in dairy is often cited as a factor that contributes to poor iron bioavailability. However, new research shows that calcium’s inhibitory effect is relatively short-lived. Calcium intake has no deleterious effects on iron levels over longer periods of time. This is of special importance for children and women who are at the highest risk of developing iron deficiency anemia, but who also have the highest need for proper calcium intake.
Last updated: October 8, 2016