Is Our Food Becoming Less Nutritious?

It hasn't actually been shown that it's the strain variation because identical strains (giving wild plants as samples) are shown to have the same declines. There's no known reason, but one decent hypothesis is that the atmosphere is changing and plants are bulking faster due to the increase of CO2. This is something you can demonstrate in a grow tent by venting in CO2. When plants have higher CO2 they increase the synthesis of carbohydrates, sugars and starches, and they decrease concentrations of protein and nutrients. This details someone of these details, including references to some of the studies you linked. Worth noting is that if GMO varieties had stark differences in nutrient content, it would be noted at the time and likely common knowledge by now. It doesn't seem to fill the nutrient gap though, and some varieties have improved nutrition profiles (though not sufficient to close the gap). link I'm not particularly pro-GMO; I think we'd be better off investing more in farming and our food in the first place. There are some things we think should be cheap in life, and food is one. We went from spending our days finding, processing, and eating food to expecting 20lb of potatoes to cost a few dollars, or less than an hour of work. There's something wrong with that picture in my mind. Even if we don't want to be farming in our day-to-day lives, I think this requires a greater investment than we're giving it. I'd say the same about education. I think it simply costs more

Veritasium did a video on this topic of vegetables becoming less nutritious ▶ this video He argues that the increased CO2 in the atmosphere is making the plants grow faster. This is making the plants produce more carbs wet to other nutrients, making the plant less nutritious compared to the past

Derek from Vertasium on YouTbe has a nice explanation. Even showing how the nutrient levels in weed specimens are also falling. The weeds were collected by researchers over the last 100 or more years. The weeds were vital because it showed it wasn't limited to farming practices it's all plants. ▶ this video

"Is Our Food Becoming Less Nutritious?: Veritasium"[1] is a good short video that puts this into context. [1]: ▶ this video