Vegetarians and iron deficiency
5 Reasons Why Vegetarians Could Be at Risk of Developing Iron & Zinc Deficiency
Our dietary preferences sometimes make us prone to some serious health concerns; therefore, a better understanding of what we eat and how the myriad of nutrients, chemicals, and compounds behave once they reach the stomach is essential to remaining healthy. Though we eat plenty of nutrients in varied proportions, yet, at times we may not be able to fulfill our bodily requirements to the desired proportions as a result we may face some very serious nutrient deficiencies.
Iron and zinc are vital nutrients for the body as they are responsible for some prominent functions, and their deficiencies may lead to serious health conditions. Even after consuming enough green leafy vegetables, whole grains, and legumes, which are rich sources of iron and zinc, vegetarians, may be at risk of becoming zinc and iron deficient. There are several reasons why vegetarians are becoming susceptible to iron and zinc deficiencies. The following information highlights the 5 most common reasons and the remedial measures one should take to optimize iron and zinc levels in the body.
Heme vs Non-heme Iron
In foods, iron exists in two forms: heme and non-heme iron. A better understanding of these two types of iron is very important because iron absorption depends on many factors including the type of iron, the presence of inhibitors, enhancers, bioavailability, physiological need, existing iron status, iron overload, and so on. The form of iron is also very important; the iron that comes from meat, poultry, fish, and other meat sources has the ability to get absorbed efficiently, which is up to 20 – 40% of the iron available.
Non-heme iron is mostly found in plant foods and also in milk, meat, and eggs. But, compared with the heme iron – its absorption is quite less. Though plant sources of iron have rich iron content, for instance, soybeans, spinach, etc., the iron that is readily absorbed from them is quite less (2 – 7%). This means non-heme iron is very difficult to absorb; however, the absorbency of non-heme iron can be improved if it is consumed along with iron absorption enhancers like citric acid, vitamin C, etc.
Vegetarians and iron deficiency: Many people around the world are at an increased risk of developing iron deficiency due to this very reason.
Phytate (Phytic acid)
The presence of phytic acid in a vegetarian diet is quite common – even the best soybeans, legumes, seeds, tubers, cereals, and nuts contain phytic acid. Phytic acid influences both the iron and zinc absorption to a greater extent making them less bio-available in the diet. Phytic acid forms complexes with iron and zinc owing to its negatively charged state and positively charged state of iron and zinc and thus inhibits their uptake.
What is the solution for vegetarians?
Vegetarians can counteract the potential negative effects of phytic acid by ensuring these measures: processing plant foods, incorporating vitamin C in the diet, and fermenting the foods. Sprouting beans, lentils, and oats helps improve vitamin C content and remove phytic acid, which is good for both iron and zinc absorption. Fermented soy products, iron, and zinc-fortified soy products can be used to mitigate the inhibitory effects of phytic acid and other compounds present in plant-based foods.
Iron deficiency and vegetarian diet: No vegetarian might have ever thought of becoming zinc and iron-deficient owing to dietary preferences, but it is a fact. For instance, for those who eat rice, wheat, and maize, their iron levels literally deplete due to the phytate factor, which is a potent iron inhibitor. In addition, daily consumption of tea, coffee, red wine, and cocoa-rich beverages can further lower the already depleting iron levels – the reason – phenolic compounds (EGCG). Apart from phytic acid, a vegetarian diet has numerous other compounds including flavonoids that inhibit iron absorption.
Iron deficiency plant based diet: Vegetarians’ problem does not end here as they tend to consume beans, lentils, and spinach – these vegetables too inhibit iron absorption. Polyphenols form iron-tannin complexes and inhibit iron absorption. Incorporation of a vitamin C-rich diet can negate the effects of phenolic compounds in the tea and vegetable diet.
Ascorbic Acid and Heat
Ascorbic acid is the most potent iron enhancer in the meal as it compensates for the adverse effects of phytic acid and fiber. Its role is significantly important when it is associated with other components of the meal. Ascorbic acid-induced iron absorption is higher if the meal is consumed in the morning along with the fruits or vegetables that are rich in ascorbic acid.
The effect of ascorbic acid is huge even if the meal contains plenty of fiber, phytates, and polyphenols. Apart from vitamin C, other acids such as lactic acid, malic acid, citric acid, and tartaric acid found in foods (vegetables and fruits) augment iron absorption. However, the solubilizing effect diminishes if vitamin C (ascorbic acid) is consumed a few hours before the meals. Unfortunately, the beneficial effects of ascorbic acid are lost while cooking foods because vitamin C (ascorbic acid) is a heat-sensitive vitamin. Those who are not eating enough fruits and vegetables that are rich in vitamin C must include them in their diets to overcome this problem. But, they should eat fruits and vegetables rich in vitamin C without cooking them so that vitamin C remains intact.
The effect of calcium on iron and zinc absorption is a bit complex affair as it needs a fairly strong debate. Calcium-induced effect on iron absorption depends on certain factors like the amount of calcium consumed, the composition of the meal, and the size of the meal. Excessive and prolonged usage of calcium-rich antacids is strongly discouraged in individuals who are iron deficient. People who consume lots of dairy products like curd, and milk yogurt that are rich in calcium should be encouraged to have fruits and vegetables that are rich in iron. Maximization of iron absorption can be possible provided calcium and iron consumption is separated.
Anemia and plant-based diet: Vegetarians and vegans are prone to iron deficiency. A vegetarian diet contains just as much iron as a non-vegetarian diet. Though vegetarians consume as much iron as non-vegetarians, they are still at increased risk of iron deficiency. This is due to the fact that they consume non-heme iron which does not absorb as efficiently as heme iron. This means the bioavailability of non-heme iron is less compared to heme iron. Therefore, nutritionists recommend vegetarians consume double the amount of iron than non-vegetarians to compensate for reduced absorption. Vegetarians Can maximize their bioavailable iron from their diet by including citrus fruits rich in vitamin C (oranges, lemon, limes) and dark green leafy vegetables in their diet. They can do this by drinking citrus fruit juice while eating.
Good sources of non-heme iron are kale, spinach, apricots, raisins, and beans like soybeans and lentils.
Can vegetarians take iron and vitamin C supplements? And, which supplements are the best for them – We will discuss more about this in our next blog