Hydroponic sage cultivation. Sage plants being grown in a laboratory using the nutrient film technique (NFT). This uses a pump to pass a nutrient solution over the plant's roots, an efficient and cheap way of growing plants without soil. Following a medical trial in 2003, oils from sage leaves are being investigated as a means of slowing the onset of Alzheimer's disease. Sage species being investigated include Salvia lavandulaefolia and Salvia officinalis. Part of the research looks at plant nutrient levels to try and increase the yield and quality of the sage's essential oils. This research is being carried out at laboratories at the Universities of Newcastle and Northumbria, UK, as part of work by the Medicinal Plant Research Centre.