Researchers from Spain, following 12,059 volunteers in the SUN Project found that both trans fats and saturated fats increased the risk for depression, and that olive oil appears to protect against mental illness. Trans fats seems to be the most harmful. The greater the amount consumed the higher the risk for depression, with a 48% increased risk over those who did not eat trans fats. What was most interesting is that the population studied ate every low levels of trans fat, only 0.4% of their total energy intake. Despite these low intakes the risk for depression was high.