Depending on pH, it is sometimes present in the form of lactic acid. However, with the neutral pH maintained by the body, most lactic acid will be present in the blood as lactate. 1  Lactic acidosis is most commonly caused by an inadequate amount of oxygen in cells and tissues (hypoxia).
While olive oil typically doesn't come with negative side-effects, it is pure fat -- which contains more than double the calories of carbohydrates or protein. Therefore, overconsumption can lead to weight gain, which may contribute to heart disease and some types of cancer, according to The New York Times Health Guide..
I can't say that olive oil is harmful for me, and by the way I have quite strong stomack. But I also tried various oils and find that olive oil - and specifically extra virgin olive oil - cause something like bad feeling in my intestines, something like irritation. Refined olive oil doesn't do anything.