Heirloom vegetables grow more slowly and spoil much more quickly than modern crops. This is because modern crops have less nutritional value - https://jeroenvanbaar.substack.com/p/data-dispatch-4-the-falling-nutritional
That article recommends eating a better diet. Sure. Seems a bit idealist. Here's some more actionable advice: everyone should take a multivitamin and magnesium glycinate. If you live somewhere that gets a winter take vitamin D too.
I'm speaking from experience here, I used to get sick every winter and my skin would get so dry it would crack and bleed. Take your vitamins.
Yes, they do.
(Desk meaning the table my surfing machine rests on. I have never consumed canned fish at the workplace. The NAFC stands for and promotes a responsible use of canned fish.)