1 Corinthians 10:26

For the earth is the Lord's, and the fulness thereof (KJV)

Then: The reason Corinthians could eat the food is that it was created by the Lord.

Now: The areas of concern in lives of today's Christians may not always have the basis of being created by the Lord, or as Baker (p. 151) elaborates, coming from God's provisions. Some foods and situations get mixed in with the desires and goals of people through whom a product appears. Proponents of organic foods versus fertilizers versus pesiticides conflict with each other on the grounds of chemical purity or "feed the world. Both approaches can honor the Lord's creation with the hope of helping others physically. When compared with the Lord's primary hope that all mankind come to know and serve him though, both come out as less important. The overriding hope of making individual actions aid in the salvation of others takes prominence.

Extra source: Cornerstone Biblical Commentary 1 Corinthians (William Baker), 2 Corinthians (Ralph Martin & Carl Toney), ed. by Philip Comfort. Carol Stream: Tyndale House Publishers, c2006.