A startling vindication of Cunningham’s assertion that a modest increase in pressure improves health has come from a study in Israel of patients with advanced lung disease, published in the journal Chest in 1996.17 The patients who were all receiving supplemental oxygen in Jerusalem were taken down to the Dead Sea to see if they would benefit from the higher level of oxygen in the denser air. Jerusalem is 2,600 feet (800 metres) above sea level, and the Dead Sea is 1,300 feet (402 metres) below sea level, giving a total reduction in altitude of about 3,900 feet (1,200 metres). On the satellite image (see the photo above), which shows the Red Sea's Gulf of Suez and Gulf of Aqaba, the Dead Sea is the stretch of water on the right below the Mediterranean.