Just take a bite: Why a whole is better than the sum of its parts
There are a number of theories as to why supplements drawn from nutritious foods simply don’t do as much for the human body. Read on as Swetha Sivakumar explains why the whole fruit, or vegetable, or grain is usually best.
I want to talk a little bit this week about whole foods, and how they’re vanishing from our diets. I don’t mean just whole grains but also whole legumes, and fruits and vegetables in their whole forms.
As science makes greater inroads into food, we’re slicing and dicing ingredients into chemical components, breaking foods down into extracts, isolates, fortified elements. The results are impressive: A shake made up largely of whey protein; fortified white rice in place of brown; coconut oil with only medium-chain triglycerides (you might know it through its acronym, MCT).
But are we losing more than we gain, in these efforts to “improve” upon what Nature provides? This is not a new question. In the 12,000 years since the advent of settled farming, humans have selectively bred grains, vegetables and fruits to maximise yield or starch or sugar content. As we tinkered, yields rose and changed as we desired, but levels of vitamins, fibres, minerals and antioxidants declined. Compared to cultivated tomatoes, for instance, wild tomatoes have 30 times more lycopene. The wild potato has 20 times more antioxidants than our modern potato.
Meanwhile, scientists began to discover just how vital these nutrients were. Since the 1950s, researchers have isolated thousands of phytochemicals (flavonoids, anthocyanins, polyphenols, etc), often touted as superfoods in themselves. More work is underway.
Each time a new set of studies shows a correlation between a certain phytochemical (such as lycopene) and a significant health benefit (such as a lower incidence of cancers), there is a frenzy to isolate the element and bottle it.
Once again, it turns out that we are missing the big picture. Studies are now showing that some supplements, such as isolates of botanical compounds, though packed with the desired component, simply do not work as well as the whole fruit or vegetable. A study published in Nature in 2000 found that 100 gm of apple, which contains only 5.7 mg of Vitamin C, has the antioxidant activity of a 1500 mg Vitamin C pill.
How is this mathematically possible? One explanation is that the antioxidant activity is occurring due to some combinations of phytochemicals that we are yet to discover. Another theory is that phytochemicals work synergistically; they need the other elements present in the food item, in order to be most effective. Isolate them and they do not work as well. Isolate them and the human body cannot absorb them as well either, again as a result of the missing synergies between components.
Meanwhile, the race to break things down continues. For the food-processing industry, breaking down food and isolating nutrients makes ingredients easier to work with and increases shelf life. Refined oils, for instance, last much longer than unrefined ones. But it’s important to remember that refined oils have been stripped of much of what made them good for humans in the first place: vitamins, tocopherols, polyphenols, etc (plus lots of complex flavour molecules).
My husband, a space geek, likes to joke that someday in the future, when humans are on their way to Mars, we’ll all have to eat fake foods every day. I like to think that if we’re going to Mars, we’ll hopefully have figured out how to synthesise food better. Either way, we’re not on our way to Mars right now. So just eat the apple or the orange or the tomato. We’ve done too much to them already.
(To reach Swetha Sivakumar with questions or feedback, email firstname.lastname@example.org)