Olive leaf and its extract is not going to be a panacea for your health if you're not eating a healthy diet and following other health advice.

So, consuming raisins may up your blood sugar levels, but because they contain a good amount of dietary fiber, minerals and protein, it should help slow the spike, says Martin.

Olive leaf extract may reduce blood pressure, improve blood lipids and help the way our bodies handle glucose. But the evidence isn’t clear cut.

It appears safe up to 1g a day, according to studies that have used olive leaf extract. However, there are no official guidelines about how much is safe to consume.