Palm

In a groundbreaking study, a healthy fatty acid in olive oil has been found to "supercharge" immune cells that fight cancer. Meanwhile, another kind of natural fat undermines the health of the same cells, killing them off and triggering inflammation.

Palm oil is a very widely-used food ingredient, but its production has a huge environmental impact, plus it may not be entirely healthy to consume. A greener, "lower-fat" alternative could be on the way, however, in the form of oil produced by algae.