At a workshop that I led last week, I was asked whether it was worth eating lettuce because it doesn’t have any nutrient value. I knew that this would be a great so-called nutrition “truth” that I can bust for you too.
All over the internet, in books, even in grocery stores, you’ll see vegetables ranked based on a score of nutrient value. But just because these scores are popular, doesn’t mean that you should believe in them.
You see, I am a true scientist. A true scientist understands what we know, and acknowledges what we don’t know. The real truth is that the scientific understanding is in its infancy regarding exactly what it is in each and every vegetable that is healthy. We know of many vitamins, minerals, and other phytonutrients. But there are likely tens, hundreds, thousands more that we haven’t yet discovered. And that’s just the nutrients that are healthy for our bodies. We’re also discovering more and more about the many roles that our gut microbiome has on our health. Science has even more of a rudimentary understanding of what it is in vegetables that makes our gut bacteria happy.
Let me share a few examples to illustrate my position. When I did my undergraduate degree in nutrition from arguably the best nutrition school in in Canada during the mid-90’s, I was taught:
- There is no nutritional value in onions and garlic. Their only role was to provide taste. Now we know that there are health-promoting phytochemicals in onions and garlic. Onions and garlic certainly do count in your daily servings of vegetables.
- Nothing about phytochemicals. That’s because the whole class of phytochemicals had not yet been discovered. All that science knew at the time was vitamins, minerals and fibre.
- That the gut microbiome simply helped digest food. It didn’t play any other role in human health. Now we’re learning that it may be linked to depression, heart health, obesity, food allergies, and a wide range of other health conditions.
Now I want to be really clear here. I’m not telling you that vegetables aren’t healthy. Vegetables certainly are healthy. In fact, I want about half of what you eat to be vegetables. I just don’t want you to buy into these various rankings of the “best” vegetables. Also, I don’t want you to buy in to the idea that certain vegetables have no nutrient value. Yes, even iceberg lettuce.
Instead of thinking that a vegetable has no nutrient value. I recommend thinking that science has not yet discovered what’s healthy about this vegetable.
So how do you apply my message? Eat lots of vegetables. Make vegetables be about half of what you eat. As wide a variety of vegetables as you can get. Eat any and all the vegetables that you enjoy. And, try new veggies often. Eat them raw sometimes. Eat them cooked sometimes. Because our bodies better absorb some nutrients when the veggies are raw. And, our bodies better absorb some nutrients when the veggies are cooked.
Photo credit: Petra Cigale on Unsplash