It’s safe to say you already know that dark chocolate is healthy. After all, dark chocolate is full of antioxidants, can lower blood pressure and possibly prevent Alzheimer’s disease, making the rich treat practically a health food. Well, not exactly, as Vox pointed out in its investigation of how the one-time junk food rebranded itself into a superfood. It turns out, all of the hype around chocolate possibly preventing dementia comes down to a lot of industry-funded research, and one small, faulty study in particular that touted its cognition-enhancing benefits.

Related: Even light drinking increases your risk of cancer, doctors warn 

Journalist Julia Belluz dove into the science behind the health benefits of chocolate and discovered that Mars alone funded 100 studies relating cocoa back to health. Perhaps unsurprisingly, 98 percent showed chocolate as a good thing. Many more studies have been sponsored by other corporations like Nestle and Hershey’s. As Belluz points out, some of the studies were well-executed and seem reliable. Others do not.

One study in particular stuck out to Belluz. Conducted by Columbia University, and paid for by Mars, it caught the journalist’s eye because so many researchers were criticizing it. On PubMed Commons, where researchers can chime in on one another’s work, one scientist points out that the research uses a small, short-term trial of healthy adults and does not meet all of the requirements for a well-executed study. Another researcher writes, “It astonishes me that this study should have been trumpeted as though it represented a great advance.”

Nevertheless, it didn’t stop the research from being praised in major media outlets. While there are many problems with the study, one of the main issues is that it never proved cocoa supplements slowed decline in memory. Instead, Belluz points out that researchers showed that for a very brief period of time, a small group of people experienced some benefits from cocoa flavonol supplements to a very specific region in the brain when researchers analyzed results with a very specific test.

Stories on research about chocolate have become popular, because well, everyone wants to feel good about indulging in the food. Other studies have attempted to link cocoa or chocolate with decreased heart disease. Some evidence from population studies indicate a link between eating the confection and a decreased risk in cardiovascular disease, but a study from 2015 concluded that while cocoa might provide some cardiovascular benefits, there just isn’t enough evidence to support eating it for heart health.

While health professionals won’t say that a few bites of dark chocolate is bad, its benefits have been greatly overhyped.

“Dark chocolate probably has some beneficial properties to it, but generally you have to eat so much of it to get any benefit that it’s kind of daunting, or something else in the product counteracts the benefits,” Salt Sugar Fat author Michael Moss, told Vox in an October piece by Belluz. “In the case of chocolate, it’s probably going to be sugar.”

So if you eat chocolate daily for a heart and brain healthy boost, you might want to rethink that strategy.