Bioaccessibility
ˌbaɪ.oʊ.əkˌsɛs.ə.ˈbɪl.ɪ.ti
The proportion of a nutrient or beneficial compound in food that is actually released during digestion of the food and made available for the body to absorb in the gut.
Full Explanation
When you eat a meal, your body doesn't automatically get access to all the nutrients that food contains.
First, those nutrients have to be freed from the food's physical structure during digestion, a process that happens as food breaks down in your stomach and small intestine. Bioaccessibility describes how much of a given nutrient or beneficial compound successfully gets released from food during that digestive process and becomes available at the gut wall for absorption.
It is shaped by several factors: how a food is grown, stored and cooked; the physical structure of the food itself (called the food matrix); the presence of other nutrients in the same meal and even an individual's digestive health.
A food can be rich in a nutrient on paper, but if that nutrient is locked tightly inside the food's cells or bound to other compounds, very little of it may actually become bioaccessible.
Why It Matters
Bioaccessibility explains why two people eating the same diet can have very different nutritional outcomes, and why cooking method, food pairing and processing really change what your body gets from a meal. It is a key concept in ensuring more nutritious foods and understanding diet-related health gaps.
Example
Raw carrots are high in beta-carotene, but the compound is tightly bound inside plant cells. When carrots are cooked and eaten with a small amount of fat, like a stir-fry, more beta-carotene is released and becomes bioaccessible, meaning your body has a better chance of actually using it.
Common Misconceptions
- ✗
"The nutrition label tells me exactly what nutrients I'm getting". Not quite. Labels reflect what's in the food, not what your body gets.
- ✗
"Bioaccessibility and bioavailability mean the same thing". They don't. Bioaccessibility is what's released from the food during digestion while bioavailability is what ultimately gets absorbed and used by the body; bioaccessibility comes first.
- ✗
"Processing destroys nutrients". Some processing like fermenting or cooking can actually increase the bioaccessibility of certain nutrients by making them easier for the body to release and absorb.