UK researchers described it for years. Our veggies are less nutrious

 https://www.nationalgeographic.com/magazine/article/fruits-and-vegetables-are-less-nutritious-than-they-used-to-be

#MacCarrison 

https://en.m.wikipedia.org/wiki/Robert_McCarrison

https://en.wikipedia.org/wiki/Robert_McCarrison 

Michael Crawford described this change several years ago.

The question is the magnitude.