When Louise and I were first married and she was pregnant with our first child, we got serious about vegetarianism and nutrition. Every weekend weâd head to the farmers market in Detroit and come home with organic fruits and vegetables by the case. Our thinking was simple: whatever was in those cases was what our new baby was going to be built out of, so it had better be the real thing.
New research suggests that our obsession with âorganicâ and locally farmed food was a good choice; the food we find in grocery stores today simply isnât the same as what was available decades ago.
The first shock study came about twenty years ago, when biochemist Donald Davis of the University of Texas compared USDA measurements of nutrients in 43 different fruits, grains, and vegetables between 1950 and 1999. Over that half-century, the median crop lost 6 percent of its protein, 16 percent of its calcium, 15 percent of its iron, about 20 percent of its vitamin C, and 38 percent of its riboflavin.
And now, two decades later, a new review in the peer-reviewed journal Foods found things have gotten worse, calling the results âalarmingâ and pointing to multiple recent studies showing nutrient levels in grocery-store staples are down by between 25 and 50 percent.
The earlier studies concluded the problem was that our soil was being depleted of nutrients, with farmers adding in chemical fertilizers that just promoted growth but did little to provide trace minerals and produce micronutrients. This more recent study, though, points the finger of blame to the plants themselves.
They took the older, more original versions of these grocery plants and grew them in the same soil next to the newer, often genetically-modified versions that are bred to increase the size and yield of their fruit, grain, or edible portion of the vegetable. It turned out the soil was a minor variable compared to the genetics of the plants.
Scientists call this the âdilution effectâ because when you breed a plant to grow bigger and faster â and then jack it with fertilizers â it bulks up on water and starch faster than it can produce the nutrients that we need.
Every plant we eat carries the result of millions of years of evolution working out how many nutrients each root, leaf, fruit, and grain needs to be appealing and supportive of the animals higher up the food chain who eat it.
âGoodâ plants get tended and supported, and their seeds get spread by animals that eat them and then release the seeds with their nutrient-rich feces. âBadâ plants have to go it alone.
Davis had noted years ago that thereâs a well-documented trade-off between fruit size and its vitamin C content per gram or ounce of fruit flesh. And whatâs happened here in America, where factory farming has become dominant, is that our âfood scientistsâ with the Big Ag outfits have chosen size over nutrients.
And then thereâs the global warming aspect of this nutrient crisis. Last year researchers at Leiden University pulled together nearly 60,000 measurements across 43 crops and found that plants grown in the carbon dioxide levels weâre headed toward have less zinc, iron, and protein. So itâs not just Big Ag; itâs also Big Oil and Big Coal thatâs depleting our food of nutrition.
And then, of course, thereâs the dirt itself. Before factory farming, it was itself a nutrient-dense mixture of decaying plant matter, fungi, and bacteria that all served to help transfer sugars and minerals between plants and soil and, sometimes, between plants themselves.
National Geographic reported, that heavy irrigation and chemical fertilizers disrupt that relationships, basically killing off our soil. When geologist David Montgomery at the University of Washington compared eight pairs of neighboring farms, the ones that had spent years rebuilding their soil with cover crops, diverse rotations, and no tilling grew food with 34 percent more vitamin K, 15 percent more vitamin E, and 17 percent more vitamin B2 than the conventional farms next door. Feed the life in the soil, in other words, and the soil will feed you.
That said, even if youâre eating vegetables from the supermarket that donât show up on the organic aisles itâs still important to maintain a diet heavy on plants. The real damage done to us by our food supply happens when we refine these foods, cook them intensely enough that theyâll last in a frozen meal or a can, or mix them with lab chemicals to create ultra-processed âfoods.â
So, if possible, find a farmer whoâs building their soil instead of pouring it full of chemicals and buy from them. Shop in the organic aisle; theyâre becoming more prevalent even in ânormalâ supermarkets and often the prices arenât that different from the factory-farmed stuff. And if you have a patch of dirt or can tend some pots, plant some heirloom varieties of the veggies and fruits you like and feed them with composted kitchen scraps.
Itâs fun, rewarding, and will keep you healthy!