If you saw my Instagram post today, I touched on bioavailability and the magic of combining different foods to unlock extra nutrition value! I wanted to touch more on this via this blog post to delve deeper into the importance of bioavailability, one of the most important and little talked about factors of good nutrition!
What is Bioavailability?
On a basic level, your food may or (may not) contain adequate nutrition and you may (or may not) be able to absorb and utilise it. Your ability to absorb the nutrition from your food is a complex topic that depends on a range of factors such as the nutrition-source quality, age and preparationand your body’s ability to break the food down via enzymes, hydrochloric acid and gut bacteria and complex post-absorption bodily processes!
As you can see it is a big topic with a magnitude of factors, though today I am going to focus on what to do to increase the bioavailability of the food we eat. Listed below are the main factors driving the bioavailability of the nutrition in your food and tips on how to increase this bioavailability:
As most know, different foods have different nutritional value and more so how the food was produced varies the nutrient value! A study reviewing the differences in growing conditions including soil health, sunlight time and water content, concluded vast differences in iron, calcium, magnesium and phosphorus; tomatoes’ iron content ranged a jaw dropping 1ppm to 1938 ppm and calcium in lettuce ranged from 6 meq/100gm to 71 meq/100gm!! That is serious stuff! Although you can’t test the amount of nutrients in your lettuce or tomato at Coles before you decide which one to purchase, you can eat a variety of produce to help increase nutrient variety. Consider purchasing produce from different suppliers, rather than sticking to the same one each time!
SOIL IS KEY
Building and supporting the soil ecosystem though traditional composting, aerating and root spacing is an important factor nutritional yield. According to SARE, biologically healthy soil contains a multitude of different microorganisms from bacteria and fungi to larger organisms like earthworms and ground beetles. This type of thriving soil produces a well-decomposed organic matter and healthy soil that holds onto calcium, magnesium and potassium, keeping these nutrients in the plants’ root zone. This is a little tricky though research the producers soil practices or ask the farmer at your local farmers market!
FRESH + LOCAL
Once you pick the right produce, eat it ASAP! Plants lose nutrients after they are picked, through a natural process called respiration. Essentially the plants are using their own stored nutrients to stay alive by breaking down and releasing nutrients – this process is exacerbated by warm temperatures, rough handling across states (or countries) and the cellular respiration rate of the specific vegetable or fruit. If the respiration rate is high, you should be eating that produce as close to its pick-date as possible, which means shopping at a local farmers market for fresh produce. For example, freshly harvested broccoli has a very high respiration rate and even though refrigeration slows deterioration, research out of Berkeley published in Nature showed that vitamin C levels were undetectable 7 days post harvest. If you can’t find local organic broccoli a frozen organic option would be better!
Anti-nutrients like phytates and lectins, found in rice, nuts and seeds, make nutrients less bioavailable in our body. Most often anti-nutrients are the plant’s basic self-defense mechanism, like phytates, which bind with zinc, iron, and calcium in the GI tract, making them inaccessible. Though, soaking and/or sprouting deactivates anti-growth enzymes enhancing the bioavailability of nutrients like vitamin C, folate, zinc, iron and calcium while leading to reduction in carbohydrates and an increase in protein- BINGO!
COOKED + RAW
This one isn’t as straight forward as it seems and totally depends on the produce you consume and nutrients you are looking to absorb. Many vitamins can be lost with cooking and on the other hand, the bioavailability of some minerals and phytochemicals is enhanced with cooking, like calcium, iron, lycopene and potassium. Therefore, Mix it up - Eat both raw and cooked vegetables throughout the day. For example, enjoy raw mushrooms and onions on a spinach salad for lunch and sauté them up for a stir-fry at dinner.
Digestion occurs in phases, including chewing, digestive enzymes and stomach acid, which all work to breakdown our food and unlock the nutrition within. As you chew your food, the enzyme amylase breaks down carbs and starch. Then your stomach releases proteases for protein-digestion and hydrochloric acid, which kills or inhibits bacteria and provides the acidic pH of 2 for the proteases to work. More digestive enzymes are then released from the pancreas into the stomach and small intestines. Unfortunately, stress, medications and poor food choices can contribute to the lack of enzyme and HCL production, which can decrease the bioavailability of the nutrition from our food. Some of these things we cannot control or are unaware of, though one thing you can do is chew your food completely! Additionally, if you feel like you have digestion problems, consider asking your doctor about being tested for low hydrochloric acid and/or supplementation.
Inside your colon lives a microbiome; this bacterial ecosystem accounts for the majority of cells in your body and functions to help breakdown and ferment insoluble fibre. This process results in the subsequent absorption of short-chain fatty acids as well as the creation of vitamins such as vitamin K, vitamin B12, thiamine and riboflavin! Therefore, the bioavailability of certain nutrients depends on the thriving ecosystem living in your gut. To ensure our gut microbiome is thriving avoid antibiotics, birth control, pesticides and chemicals in food and limit sugar, alcohol and white carbohydrates. Eat fiber and resistant starch to help feed your healthy gut bacteria and consider taking a probiotic to enhance microbiome proliferation!
Phew – that was a lot of information I know! But this is a super important topic and actually incredibly interesting! Feel free to contact me with any questions or go ahead and read some of the amazing studies on google!