The problems seem to come with sage oil being taken - its poisonous or excessive drinking of sage tea.
Sage has been used in cooking and as a herbal remedy for centuries.
Sage has been found to have antiseptic, antimicrobial, astringent, antioxidant, anti-inflammatory, antifungal, antiviral, hypoglycemic, antiatherogenic and antimutagenic properties. Sage contains numerous biologically active compounds, including caffeic acid, camphor, carnosol, carnosic acid, cineol, epirosmanol, galdosol, genistein, isorosmanol, limonene, luteolin, rosmanol, rosmarinic acid, thujone, and ursolic acid.
There has been research done that suggests carnosol and carnosic acid can arrest the development of some cancer cells.
If you are breast feeding then sage is a folk remedy to reduce lactation, although the limited studies show it increases lactation in rats.
Unless you are planning to eat sage-encrusted sage in a sage sauce every day for a year I wouldn't think the tiny amount of sage in a recipe would do anything.