The latest in ‘things that are good for you are until, just kidding, they are actually suddenly bad for you’ comes courtesy of researchers at Emory University, who have led a recent study finding that so-called good cholesterol might be as bad for you as bad cholesterol.

For anyone who can’t keep up here’s a bit of background: For decades, cholesterol was the thing in food that was going to kill us all by hardening arteries. The belief, promoted by the nutrition field, spawned a slew of ‘low fat’ ‘lite’ and ‘diet’ food offerings. Then, cholesterol was split into two categories: Bad cholesterol, or LDL (low-density lipoprotein), and good cholesterol, or HDL (high-density lipoprotein). LDL was responsible for hardening arteries and causing heart attacks, while HDL played a role in cleaning out the very same arteries and clearing LDL from the body. Foods high in HDL — avocados, chia seeds, legumes and nuts, coconut oil, and more — were encouraged, many of them finding their way onto ‘superfood’ lists, while foods high in LDL — butter, eggs yolks, fried foods, fatty red meats — were persona non grata.

Then, in 2015, like a delicious miracle, the nutritional ban on LDL foods was lifted. Cholesterol, even LDL, wasn’t the culprit of bad health anymore — sugar was. LDL foods were okay in moderation, and HDL foods continued to be ‘super’ — good for you in abundance. Until now.

“It may be time to change the way we view HDL cholesterol,” says Marc Allard-Ratick, of Emory University School of Medicine, Atlanta, US. Allard-Ratick is the lead author of a new study, presented recently at the European Society of Cardiology’s annual meeting. “Traditionally, physicians have told their patients that the higher your ‘good’ cholesterol, the better. However, the results from this study and others suggest that this may no longer be the case.”

In the past, HDL has always been called the ‘good’ cholesterol because it helps conduct the bad cholesterol lining blood vessel walls to the liver, where it is filtered out of the body. High HDL levels were thought to lower LDL levels and thus, chances of arterial hardening and cardiovascular diseases later on. However, Allard-Ratick says, scientists have yet to prove that HDL is actually protective. In fact, the very same high quantities that nutritionists have advised as healthy, may actually be as bad as high levels of LDL.

Allard-Ratick’s team tracked 6,000 participants, most of whom already had heart disease. They were divided into five groups of varying HDL levels. After roughly four years, researchers checked in; 13% of participants had had a heart attack or had passed away due to cardiovascular causes. As expected, many of these ailing or deceased participants came from the group with low levels of HDL, or ‘good’ cholesterol. But surprisingly, the other most at-risk group was the group with the highest levels of HDL — theoretically, the group who should have been least at-risk, based on earlier assumptions about good cholesterol helping clear away bad cholesterol. The people in this group had an almost 50% greater chance of dying from cardiovascular problems than those in the mid-range of HDL levels.

The findings were consistent even after taking into consideration other factors that increase heart disease risks, such as diabetes, smoking, LDL cholesterol, as well as other factors that could influence to HDL levels — like alcohol consumption, race and sex. Allard-Ratick says his study is one of “a steadily growing body of evidence that very high HDL cholesterol levels may not be protective.” Like any good scientist, he’s calling for more research, even though he seems pretty sold on his finding.

“One thing is certain: the mantra of HDL cholesterol as the ‘good’ cholesterol may no longer be the case for everyone,” concludes Allard-Ratick.

Another thing seems certain, at least, to the layman — that nutritional advice may come and go, but moderation is always in fashion.