Joined: Mar 2009
Posts: 5039
"grown properly"
5/31/2017 at 10:56 AM
I find that statement so odd. I mean yes, soil depletion is an issue in many regions but if it were really that bad the plants wouldn't grow. If the plants don't have enough nutrients they won't survive, so the fact that the plants even exist means clearly they have enough, therefore will contain enough micronutrients.
The biggest issue, IMO, is that we don't eat the variety that we need, and that we're biologically adapted for. Since the advent of agriculture, we've reduced the variety in our diet dramatically, from hundreds if not thousands of items/species to a mere few dozen on average. At most, maybe a hundred, and those would be people who eat a really good diverse range of fruits/vegetables, seeds/nuts and non-wheat grains. Honestly, vegans probably tend to have better health not because of the exclusion of animal products but because of the inclusion of more variety via plants-based foods, on average.
We evolved as hunter-gathers, and as such during foraging we would eat what we found, and because our local was always moving we always had different sources and selection. Sometimes only a few bites here and there, but the effects were cumulative. We got a broad range of nutrition from many sources, and it varied hugely from day to day and season to season.
Think now about the typical standard diet - most grain is wheat and corn (sometimes rice), we might have dairy, maybe a dozen different fruits or vegetables during the day (if that), a few nuts or seeds, maybe some eggs or meat. That's pretty much it. You might cover 2 dozen different species in a day, and then you'll eat the same thing tomorrow, and the day after that, and the day after that. How much does your shopping list actually vary? How many different things do you in fact buy in the store?
Taking a multivitamin pill doesn't fix the underlying problem. Taking specific supplements to fix certain shortages helps, but the bioavailability is terrible in most of them - an iron supplement, for example, your body can only absorb about 10% of the iron in it. Compare that to heme iron in a piece of meat - it's better at 25% or so. Added iron in baby formula is absorbed only at about 10%, but iron in breastmilk pushes 75% because of bioavailablility, so even the very low amounts are used much more effectively.
It's the variety in our diets that really determines whether or not we meet our nutritional needs.