Those well versed in nutrition will be familiar with the idea of bioavailability, but it isn’t a widely known concept. Although it is an important one. Bioavailability, in the world of nutrition, is about the proportion of a nutrient which is actually absorbed into the body after eating. The pharmaceutical industry coined the term to describe the proportion of a drug that enters circulation and can have an effect. A drug administered intravenously (ie straight into the bloodstream) has 100% bioavailability whereas something taken orally will have degrees of bioavailability depending on the obstacles it faces on its progression to the gut and absorption into the circulatory system. Likewise food has to be broken down and passed through the digestive tract before being absorbed into the body. The availability of nutrients will depend on the source of food from which they come as well as a number of other factors.
Just eating food doesn’t automatically mean all its inherent nutritional value is absorbed and used to assist in normal body function. Different proportions of the nutrients we consume will actually get absorbed into the body.
Understanding the bioavailability of vital minerals and vitamins in certain foods helps us to get the right amounts of these essential nutrients. This is especially important in the case of restricted diets where the food sources of certain nutrients are limited.
Veganism is growing*1 and people are opting for a flexitarian diet which results in an increased consumption of grains, nuts and vegetables and a decrease in the consumption of meat and dairy. These lifestyle choices have many health and sustainability benefits but they are also accompanied by nutritional challenges.
Iron is one of those minerals which is harder to get through a vegan and vegetarian diet*2.
Although micronutrients like iron and zinc are present in nuts, grains and legumes, their bioavailability is less than in meat*3. There are concerns that vegans and vegetarians are at higher risk of iron deficiencies because it isn’t easily available to the body from the foods in their diet.
Understanding the factors which affect bioavailability helps us to understand how to increase the availability of vital nutrients in plant based diets without just using supplements.
A factor which has been shown to impact mineral bioavailability is the presence of anti-nutrients within a food. Anti-nutrients*4, as the name suggests, inhibit the uptake of nutrients . The anti-nutrients present in legumes, grains and nuts are phytates. They reduce the bioavailability of zinc, iron and calcium by binding with them and stopping them transferring through to the bloodstream.*5
There are ways to combat phytates, one of which is soaking and cooking*6, which degrades the phytates. Fermentation is another way to degrade phytates*6. It has been shown that certain good bacteria produced through lactic- fermentation break down phytates and by extension increase the bioavailability of iron, zinc and calcium.
Lacto-fermented cabbage, like Bodkin’s, has been observed to enhance iron absorption from a meal*7. An important study by Nathalie Scheers, Lena Rossander-Hulthen, Inga Torsdottir, and Ann-Sofie Sandberg investigated the bioavailability of the mineral iron in raw vegetables vs fermented vegetables*8. The research showed the bioavailability of iron was greater in a meal accompanied by fermented vegetables than one accompanied by raw vegetables.
Bodkin’s fermented cabbage is, therefore, a great source of absorbable iron making it the perfect condiment to complement any meal not just for the taste but for the nutritional benefits. It is an especially valuable condiment to accompany a vegan and vegetarian meal because it is such a good source of absorbable iron.
Bodkin’s naturally fermented cabbage has been fermented for a minimum of three weeks. The bacteria in Bodkin’s has been analysed in the labs at Campden BRI and it contains many, many strains of good bacteria. There are high levels of the bacteria, Lactobacillus Plantarum in Bodkin’s. This strain of bacteria has been shown to be associated with the successful degradation of phytates in certain grains*9. Carrizol et al’s*9 research shows animals fed with bio-enriched pasta fermented by the bacteria Lactobacillus Plantarum had higher concentrations of minerals Phosphorus, Calcium, Iron2+ and Magnesium compared to a control group that hadn’t eaten the pasta.
People looking to maximise their nutritional uptake should consider regular consumption of Bodkin’s fermented cabbage because of its natural mineral benefits.
Bodkin’s is a really great source of absorbable iron and good bacteria that can degrade anti-nutrients. It is the perfect condiment by adding nutritional value to a meal and tasting delicious.
- Research by the Vegan Society, conducted in 2018, there are around 600,000 vegans in Great Britain.It's estimated that this is up from 150,000 in 2006, and that there are twice as many women than men who are vegan
2.Iron Status of Vegetarian Adults: A Review of Literature Roman Pawlak, PhD, RD, Julia Berger, BS, and Ian Hines, PhD .Am J Lifestyle Med. 2018 Nov-Dec; 12(6): 486–498.
Published online 2016 Dec 16. doi: 10.1177/1559827616682933
PMCID: PMC6367879 PMID: 30783404
3.Iron bioavailability and dietary reference values
Richard Hurrell, Ines Egli The American Journal of Clinical Nutrition, Volume 91, Issue 5, May 2010, Pages 1461S–1467S, https://doi.org/10.3945/ajcn.2010.28674F Published: 03 March 2010
4:Nutrition and Health Siân Astley, Paul Finglas, in Reference Module in Food Science, 2016
Antinutrients are natural or synthetic compounds that interfere with the absorption of nutrients. Examples include the following:
Protease inhibitors (e.g., Bowman–Birk trypsin inhibitor in soybeans (Birk, 1985)), which inhibit trypsin, pepsin, and other proteases in the gut, preventing digestion and absorption of proteins and amino acids
Lipase inhibitors (e.g., tetrahydrolipstatin), which interfere with enzymes, such as lipases, which catalyze hydrolysis of some lipids and fats
Amylase inhibitors in beans, which prevent the action of enzymes that break the glycosidic bonds of starches and other complex carbohydrates, preventing the release of simple sugars and absorption by the body
Phytic acid in the hulls of nuts, seeds, and grains, which has a strong binding affinity for calcium, magnesium, iron, copper, and zinc, preventing their absorption
Oxalic acid and oxalates, which are present in many plants, particularly members of the spinach family, bind calcium to prevent its absorption
5.Phytates inhibits absorption of iron, zinc calcium, magnesium and manganese ( Hallberg L, Brune M, Rossander L. Iron-absorption in man—ascorbic-acid and dose-dependent inhibition by phytate. Am J Clin Nutr. 1989;49:140–144. [PubMed]
6.Mahgoub SEO, Elhag SA. Effect of milling, soaking, malting, heat-treatment and fermentation on phytate level of four Sudanese sorghum cultivars. Food Chem. 1998;61:77–80. doi: 10.1016/S0308-8146(97)00109-X. [CrossRef] [Google Scholar] [Ref list]
7.Absorption of iron from Western-type lunch and dinner meals. Hallberg L, Rossander L
Am J Clin Nutr. 1982 Mar; 35(3):502-9. [PubMed] [Ref list]
- Increased iron bioavailability from lactic-fermented vegetables is likely an effect of promoting the formation of ferric iron (Fe3+) Nathalie Scheers,corresponding author Lena Rossander-Hulthen, Inga Torsdottir, and Ann-Sofie Sandberg Eur J Nutr. 2016; 55: 373–382. Published online 2015 Feb 12. doi: 10.1007/s00394-015-0857-6 PMCID: PMC4737790 PMID: 25672527
9.Ancestral Andean grain quinoa as a source of functional lactic acid bacteria.
Carrizo LS, Montes de Oca C, Laiño JE, Suarez NE, Vignolo G, LeBlanc JG, et al. Food Res Int. (2016) 89:488–94. doi: 10.1016/j.foodres.2016.08.013
Lactic acid bacteria from Andean grain amaranth: source of functional value enzymes and vitamins.
Carrizo SL, Montes de Oca CE, Hebert ME, Saavedra L, Vignolo G, LeBlanc JG, et al. J Mol Microbiol Biotechnol. (2017) 27:289–98. doi: 10.1159/000480542