We rely on food labels to make informed choices about which foods to eat. Labels offer us information on energy and nutrient values such as calories, protein, fat and carbohydrate. But the truth is that food is much more than a list of nutrients on a label. Simply looking at the nutrient list on a food label won’t tell you the full picture about how your body will respond to it. And we don’t eat nutrients – we eat food.
In the past, much of the nutritional research has focussed more on the relationships between individual components of foods and our health, such as how different types of carbohydrates affect energy and blood sugar levels. Or how a single vitamin affects our health such as vitamin E and its effects in the cardiovascular system.
However, researchers are now starting to focus on the idea of a ‘food matrix’ – how the physical and chemical properties of whole foods affect how our bodies break down and use the nutrients locked up inside them – and what this means for our nutrition and health.
What is a food matrix?
The food matrix simply refers to the fact that whole foods are complicated – they include water, fibre, minerals, polyphenols, vitamins, minerals and a whole host of other compounds that synergistically confer a myriad of health benefits.
But food matrices aren’t just about the nutrient content of foods. They also confer different textures and tastes. There are different types of food matrices that, like foods, take many different forms including liquids (like orange juice), gels (grape jelly), emulsions (mayo), fibrous materials (fruits and vegetables), crystals (sugar), porous structures (marshmallows) and much more.
Food matrices also affect how the body digests, absorbs and responds to the nutrients in the foods consumed. The food matrix is, therefore, an interesting concept that starts to explain why a poor diet cannot be overcome solely by taking supplements.
The food matrix changes the effects of nutrients
Much like we’ve discussed in Nutrigold blogs before about the forms of vitamins and minerals found in food supplements, the nutrient structures in the food itself affects:
- The availability of energy and nutrients
- How much of a particular nutrient is released (i.e.bioaccessibility) as food is digested in our guts
- How well we absorb the nutrients
As a result, each food’s particular matrix can make it easier or harder to break down and use the nutrients inside it.
For example, eating a bowl of porridge made from coarse-ground grains leads to a lower rise in blood sugar levels as the same amount of finely-ground cereal, yet the simple nutrient list would be identical. Similarly, there’s a lower rise in blood fat after eating whole almonds compared with eating finely ground almonds containing exactly the same amount of fat.
Another example is the different food matrices in dairy products such as milk or cheese and how they affect how well we can absorb the protein and fat from different dairy foods, even if their labels list exactly the same amounts of each nutrient.
In calcium-rich dairy foods like cheese, fat droplets are encased in membranes that reduce how much fat gets absorbed in the gut, compared with eating a portion of butter containing exactly the same amount of fat.
These matrices effects mean that some foods affect our health in ways that might not be predicted by simply looking at the label on the pack.
Messing with the matrix
It follows that food processing alters a food matrix, leaving a food matrix that is altered or incomplete from the original whole food and devoid of many health benefits. These alterations may even confer some negative effects on health if digestibility and absorption factors of the nutrients have been changed by the processing and additional compounds such as artificial preservatives and sugar have been added. Foods that contain natural food matrices (i.e. whole, unrefined and unaltered foods) therefore maximise health benefits.
When you eat whole foods like fruit, vegetables and grains, your body has to work had to release nutrients by breaking up the structures inside them, such as cell walls. This means that nutrients are released more slowly or to a lesser degree – as is the case for whole almonds coarse-grain oatmeal – helping you to feel satisfied for longer, controlling blood sugar, reducing overall calorie intake and keeping your gut healthy.
The more we process our food before eating it, the more we mess up the matrix.
Chewing, cooking and other types of food processing all change the composition of our foods, altering how our bodies digest, absorb and respond to them. In some cases this is essential. Chewing helps break down foods and stimulates gastric juices ready for further digestion. We would also struggle to get enough nourishment (or enjoyment!) from a cupful of dry rice, so we need to soak and cook it before eating. And many types of raw beans contain a toxic chemical called phytohaemagglutinin, which can only be inactivated by cooking.
But lots of processing also makes nutrients more digestible, so larger amounts of fat and sugar are taken up into our blood than would be accessible from less processed food with the same nutritional composition. A good example of this is juicing fruits where blood sugars are affected to a greater level if drinking fruit juice compared to eating a whole piece of the same fruit.
It’s not just what you eat that affects your health – it’s how you eat
We all respond differently to food
Many nutritional scientists are now focusing their attention on investigating how the matrix in different foods affects how they are broken down and used, seeing how this relates to the simple list of nutrients on the label and how it impacts on health.
But there’s an extra twist to this story.
The amount of nutrition you get from a particular meal depends not only on the physical and chemical makeup of the foods you eat but also on your body.
One study has shown that even identical twins respond differently to foods. So what does this mean for you as an individual?
In a nutshell, forget all those fad diets; there’s no one right way to eat. It’s only by understanding your personal nutritional response that you can find the right foods for your body. This may seem complicated but limiting processed foods and eating a whole food diet means consuming more suitable food matrices that support health. You could also consult a qualified nutrition practitioner who can help shed light on your body’s unique nutritional requirements.
And remember, food labelling only tells you what is in the food, not how your body will digest it and what your body will absorb and utilise. Health is not so much the familiar saying “you are what you eat” but more: “You are what you absorb”