French ecology minister Ségolène Royal made headlines this week when she urged people to stop eating Nutella, but her anger was really directed at one key ingredient: palm oil.

“We have to replant a lot of trees because there is massive deforestation that also leads to global warming. We should stop eating Nutella, for example, because it’s made with palm oil,” Royal told French television network Canal+, according to Agence France-Presse.

“Oil palms have replaced trees, and therefore caused considerable damage to the environment,” she explained.

Ferrero, the Italian company that manufactures Nutella, denied that the popular hazelnut spread is made by harming the environment, according to Ansa.

The French division of Nutella maker Ferrero replied that it only uses "100% certified sustainable palm oil for its products manufactured at Villers-Ecalles."

Oil palm cultivation "can go hand in hand with respect for the environment and populations ... no forests or other valued conservancy spaces have been sacrificed" to make Nutella, the company said.

In February, Ferrero announced that its products were produced with palm fruit oil that was 100 percent certified as sustainable and segregated according to the Roundtable on Sustainable Palm Oil (RSPO) supply chain.

Ferrero gets almost 80 percent of its palm oil from Malaysia, according to Agence France-Presse. The remainder comes from Brazil, Indonesia and Papua New Guinea.

The problem with palm oil

To make palm oil, forested land is cleared to make way for palm plantations. That deforestation can lead to the loss of species as well as global carbon emissions when the trees are burned down. Malaysia and Indonesia produce about 87 percent of the world's palm oil, according to a report in Time. The conversion from forested land to palm plantation has led to biodiversity losses has high as 12.1 percent in Malaysia — equivalent to the extinction of about 46 species.

Global production of and demand for palm oil is increasing rapidly, says the World Wildlife Fund (WWF) on its website. "Plantations are spreading across Asia, Africa and Latin America. But such expansion comes at the expense of tropical forests — which form critical habitats for many endangered species and a lifeline for some human communities."

Palm oil is found in plenty of foods beyond hazelnut spread — including margarine and ice cream — and it's also used to make soap, liquid detergent and lipstick.

This is not the first time that the French have lashed out on this issue. According to the BBC, French senators tried unsuccessfully to impose a 300 percent tax on palm oil in 2011. They argued that the oil was dangerously fattening and that its cultivation was harmful to the environment.

Related on MNN:

Mary Jo DiLonardo Mary Jo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.