We had our soil tested before we bought the property, and we are very careful about what we bring onto the property. We use no animal fertilizers, only sea products (kelp meal; fish meal; etc.) that have also been tested for toxins.
Still, for almost everyone, you can be sure that what you grow yourself is going to be a lot cleaner and safer than what you get from the store. Better the devil you know than the one you don't.
We have a 2,000 square foot deer fenced garden in which we grow vegetables year-round. In summer its mostly tomatoes, potatoes, corn, beans, peppers and herbs; and fall and spring we cabbage, carrots, lettuce, beets, and other cooler weather crops. With the fruit orchard (apples; pears; grapes; berries of all sorts; cherries; persimmons; jujube; plums; pawpaws), we grow at least 50% of what we eat.
We are thinking about getting some chickens, but just for eggs.
I've noticed that some of our neighbors are also starting gardens.
No matter what your circumstances, try to become a little more self-sufficient, even if it's just growing some sprouts inside, and a few figs and tomatoes outside in pots. It is rewarding is so many ways from savings to health.
Best wishes to all.
John