Bioavailability is something I stumbled upon recently while I was doing some research on supplements and superfoods and found it very interesting. It is the percentage of substances the human body is capable of absorbing from the administered dose. This concept is really important to medicines and drugs, for instance, but I am more focused on food now (when aren’t I?). So in this case the bioavailability of a certain nutrient is the amount which is absorbed by the body from the ingested food. For instance, how much iron does your body absorb from spinach. You would think it is all of it, but you would be wrong. As I have been. 100% bioavailability is achieved only by intravenous administration.
But why is this important, you ask? Well, I am trying to live a healthy life and eat a diversified and healthy diet, but if I’m not being smart about it, I might end up only with the idea of a healthy diet and no benefits. Even if I eat a lot of spinach for instance that doesn’t mean that I get enough iron from my diet. Unless… drum rolls please… I drink a glass of orange juice with that spinach salad! Or add some grapefruit slices to that salad. Then I will get a lot of iron from my diet, two or three times more! This happens because Vitamin C enhances the body’s ability to absorb iron from plant sources. Iron from meats, fish and eggs (a.k.a. heme iron) is more easily absorbed in comparison to the one from leafy greens (a.k.a. non-heme iron). Therefore I need to add some citrus to my spinach salad to get as many nutrients as possible. This works also with a bowl of cereals that are fortified with iron and other supplements. A glass of orange juice will do the trick. I guess you are now having an “aha” moment, just as I did: “oh, so that’s why they always have orange juice for breakfast in movies”.
There are several food pairings that work well together and there is a lot of research on this topic online. I don’t want to get into all the scientific data, because I don’t understand everything myself, but I do want to give you a basic summary. So to make a long story short, there are factors that enhance the body’s capability of absorption and others that inhibit it. For instance, related to the example from above with the spinach: if you drink coffee or tea together with the spinach salad, it will have quite the opposite effect as the citrus. But if you add some healthy fats (olive oil, avocado, nuts) to your citrus-spinach combo, you will get another boost of iron. And that’s because these healthy fats work as efficient carriers for nutrients.
Here are some other examples of food pairings, tips and tricks that enhance (the good) or inhibit (the bad) nutrient absorption:
ROSEMARY WITH GRILLED FOODS
According to the referenced study below, grilling at high heat leads to cancer-causing compounds (HCAs) forming in ground beef and other meats. The study found that adding herbs high in antioxidants to the meats before grilling decreases HCAs with up to 80%. A really practical way of adding herbs is by marinating the meat overnight. I usually mix some olive oil and herbs in a plastic bag, add the meat and let it sit for some hours in the fridge. The study showed that the most efficient herbs for fighting HCAs are rosemary and thyme.
Reference: Kansas State University Study
Tomatoes contain lycopene, a highly effective antioxidant. The studies below show that cooking tomatoes enhances lycopene bioavailability by 55%. This means that tomato sauce or tomato paste are healthier for you than raw tomatoes. In this case it is truly better to process the food than eat it raw… quite ironical, don’t you think?
RED WINE AND OMEGA-3 FATTY ACIDS
It seems that red wine enhances the bioavailability of omega-3 fats in fish and nuts. It was tested if this capability comes from the alcohol or some other substance within the wine and the experiments showed that beer or spirits don’t have the same enhancing effect. The decisive substance(s) turned out to be polyphenols…whatever those are 🙂
The suggested dose, and the one tested during the study, was one glass a day for women and two glasses a day for men. So, let me pour myself a glass of red wine and we shall continue.
Reference: Study on omega-3
SOAKING NUTS, LEGUMES AND GRAINS
Legumes and grains contain a substance called phytic acid which binds important minerals preventing your body from fully absorbing them. Not soaking grains and, thus not reducing the phytic acid, leads to mineral deficiencies, poor absorption of zinc, iron, phosphorous and magnesium.
Check out the elaborate article referenced below for a full description of the process and how exactly does soaking help. It is really detailed and shows you how you need to soak different grains and nuts. It’s mostly enough to soak them overnight in water with lemon or something acid, like a mild vinegar. But do read the article!
Reference: Article on soaking
TURMERIC AND BLACK PEPPER
I always confused the following terms, thinking it’s one and the same thing: curcumin, turmeric and curry. But here’s how it actually is: curcumin is the active substance in turmeric which gives it the yellowish color, while turmeric is a spice contained in the curry powder.
Now, it seems that when consumed on it’s own, curcumin’s bioavailability is affected by the liver’s process. When adding even a pinch of black pepper however, it’s bioavailability is increased by up to 2000%! (Yes, I counted the zeros… there’s supposed to be 3 of them.) The video below explains better why this happens.
The interesting fact about the Indian culture is that guess what they added in the curry powder besides turmeric? Black pepper! So this combination is known intuitively for centuries and has been consumed this way all along.
Reference: Video on bioavailability of curcumin
These are the tips and tricks, and food combinations that I’ve found so far. If you know any other ones, do share! It’s a pity to make the effort of eating a healthy diet and not get all the goodness out of it.
Reposted from AUGUST 28, 2015