Phytic acid and iron absorption.

Today, I'd like to delve into the absorption of iron and the general absorption of macro and micro elements in nourishing our bodies. However, focusing specifically on iron, it's one of the most crucial aspects.

For iron absorption from food, a sufficiently low pH in the stomach and functional intestinal villi are necessary.

The absorption of this element is aided by, among others, vitamin C and hydrochloric acid in the stomach. Therefore, it's beneficial to consume iron-rich products along with those rich in vitamin C and herbs that support hydrochloric acid production. Many compounds hinder iron absorption, including phosphates and phytates found mainly in cereals, whole grain products, legumes, and nuts. It's worth limiting their consumption or at least not combining them with iron-rich products. Additionally, oxalates, tannins, and tannins present in coffee, strong tea infusions, and wine also hinder iron absorption. To maximize iron absorption from food, it's advisable not to consume these drinks with meals.

Low ferritin levels (less than half of the norm) affect hormones, specifically leading to hypothyroidism.

The situation with zinc is similar to that of iron.

Animal-derived iron (bound in heme molecules) is resistant to phytic acid. However, plant-derived iron (non-heme) can bind with phytic acid, blocking its absorption. Therefore, carnivores need not worry, but vegetarians should be cautious. Some recommend vegetarians consume 80% more iron than omnivores. While somewhat exaggerated, men can easily meet this recommendation. It's important to note that iron levels in the body can be easily monitored by testing ferritin and hemoglobin concentrations in the blood. The bioavailability of iron can also be improved by adding vitamin C and other organic acids to meals. It's essential to remember that excess iron can also be harmful, and a lower intake of heme iron is one of the healthful aspects of a vegetarian diet.

What is phytic acid?

Phytic acid or inositol hexaphosphate is an organic substance found in plant products - mainly cereals and legumes, which is used to store phosphorus and, in the form of salt, potassium, magnesium and calcium. There is especially a lot of phytic acid in the outer layers of seeds (up to 90%). That's why there is more of it in whole grain cereals than in refined counterparts. There is more phytic acid in rye than in wheat, and wheat also has a lot of phytase - an enzyme that breaks down phytic acid. Salts of phytic acid are called phytates (e.g. calcium phytate). The average diet contains from 150 to 1,400 mg of it, and more in a typical vegetarian diet - from 2,000 to 2,600 mg2.

The main concern is that phytic acid forms insoluble salts with the minerals in food, which consequently partially blocks their absorption. This applies to elements such as iron, zinc and, to a lesser extent, calcium3. Sometimes magnesium and copper are also mentioned, but the effect of phytic acid on their bioavailability is ambiguous3. A popular myth is that phytic acid flushes out or otherwise depletes our already existing stores of these nutrients in the body. In fact, it only reacts with those ingredients that are contained in the same product or meal.

How to neutralize phytic acid in food?

• Soaking – leaving legumes or cereal flakes in water overnight removes up to 37% of phytic acid. The soaking water should be drained, and the product cooked in fresh water. Unfortunately, this method also removes some mineral components.

• Fermentation – sourdough bread preparation results in more phytic acid breakdown compared to yeast-based bread. To reduce phytic acid in the diet, choose sourdough bread over yeast-based bread.

• Adding vitamin C – vitamin C neutralizes the effects of phytic acid. It can be added to meals in the form of lemon juice or combined with grain products with vegetables rich in ascorbic acid, e.g., bell peppers.

• Enzymatic methods – phytase enzyme can be added to flours from legumes or grains during production, breaking down phytic acid. This process can be applied in bread production, improving the texture of the final product.

Phytic acid provided in the diet can have both positive and negative effects on health. Consuming up to 400 mg per day usually doesn't lead to deficiencies in the body. Therefore, if our primary diet consists of vegetables rather than processed grains, we shouldn't be concerned about phytic acid.

Contradictory results are obtained in many aspects, making it difficult to conclusively confirm the positive or negative effects of this compound. It's suggested that disparities in results might stem from some individuals having gut flora bacteria producing the enzyme phytase, which breaks down phytates. Phytic acid likely exhibits:

• Anti-cancer properties – as an antioxidant, phytic acid neutralizes free radicals that can cause cancers. Consuming phytic acid reduces the risk of breast and prostate cancer as well as colorectal cancer. It may also alleviate chemotherapy side effects.

• Anti-atherosclerotic effects – phytic acid prevents the formation of atherosclerotic plaques and artery hardening.

• Antidiabetic effects – phytic acid positively affects pancreatic function and insulin secretion. It lowers postprandial glycemia, prolonging the feeling of satiety.

Should we exclude products containing phytic acid from our diet?

Absolutely not...

The purifying properties of phytic acid significantly benefit our health.

Phytic acid is found in many products that are simply healthy for many other reasons.

It would be a mistake to limit them just because one of their ingredients may have unfavorable properties in terms of the absorption of certain minerals. This is important because products containing phytic acid also contain significant amounts of fiber. However, this is converted into short-chain fatty acids, which form complexes with the elements and support their absorption3. This is one of the reasons why it is impossible to predict the exact bioavailability of a given element in a specific product based only on phytic acid. Reducing the bioavailability of elements only to the amount of phytic acid is an oversimplification.

It is worth remembering that people who do not eat meat (and basically only they) must make sure that their diet is rich in zinc and iron, the absorption of which is hindered by phytic acid. This will especially apply to iron, the nutritional status of which should be monitored with blood tests and, if necessary, care for the bioavailability of this element. The solution to this situation may be eating sourdough bread.

However, in other cases, rather beneficial properties of phytic acid are to be expected and limiting it in the diet is unjustified.

AR