I started studying nutrition and supplements after some serious illness in my youth, decades ago... I've eaten legacy plant veggies, wow, way the heck better than the stuff in the supermarket.. and the cost, wow to that too... if I were gardening I would not raise anything but legacy plants though.. You can get fair nutrition out of a supermarket in the USA but you will want to supplement. The single most important nutrient that has disappeared from the food is Omega 3, supplement that, not plant source but Krill source, make sure you are not getting mercury along with it... After that, for your brain go to a health food store and look at all the brain supplments, phosphatidylserine is number one on the list for that and they have a dozen other ingredients in some of the supplements.. find one you like.. after six months on the Omega 3's and the brain nutrients things change, nothing is very difficult, depression is a thing of the past, etc... take a multivitamin with 200 mg of Magnesium and don't take calcium, the American diet is loaded with calcium and deficient in magnesium.. magnesium is really cheap, just get it in powdered form if nothing else and put it in water, that way you can control your dosage, too much and you get the runs, too little and you get nervous and your muscles ache and cramp... those are the basics as I see it.. heart disease can be prevented by taking hyaluronic acid, it keeps the soft tissues strong and it keeps the entire body's tissues moist and flexible. Your skin will soften up as proof that it's working. It will keep your arteries flexible and they won't harden and crack and form deposits that cause heart attacks.... Regarding food in the supermarkets, frozen veggies retain almost all their nutrients, fresh is good but you have to shop often as storage is a short term thing.. a good diet is 80% veggies... don't tell me about your wonderful vegan religion at all, anthropologists have proven that you cannot get all the nutrition you need from plants any place on the entire globe so forget that shit. My own research has shown me that vegans are lacking in the area of the brain nutrients and my experiences with them have proven that out, psychologist have recognized problems associated with veganism....
The Planet is over populated already and humans are still breeding like cockroaches rats. More people more asphalt more concrete more buildings more tar roofs more roads more bridges all to radiate more heat. Plow under the remaining rain forests to produce more food for fat slobs. Our oceans are dumping grounds for all our human shit and garbage we produce and our fish stocks are dying, what fisheries are left are contaminated with mercury. Swordfish, tuna, salmon populations are dying. We have raped our oceans because we need the food. California no longer has a salmon fishery and has closed to commercial fishing. We don't have salmon and steelhead runs in our rivers and streams due to The water diversion from our lakes and rivers for agriculture has destroyed steelhead and salmon stocks and the ability for these species to reproduce in our rivers and streams. Wait till the world population doubles or triples from here. We will be living packed together like sardines in a can. We are already seeing pandemics and this flu season with swine flu lurking is going to be interesting. Nature taking its course and thinning out the humans that have over run the planet. Imagine what a shit hole this planet will be in 30-50-100 years when human populations double triple. Dystopian future is guaranteed. Humanity is doomed.
If you only eat a whole foods plant-based diet (no animal products, oils or refined foods), you are right, your health should be excellent and your strong immune system will be able to fight the deleterious effects of toxins found in conventionally gown foods. But organic definitely tastes better and is way healthier for the environment than conventional.