Recent studies and experts agree: butter is back. Yet the news might be a hard one to swallow especially if you nixed it from your diet years ago.

So how much butter is beneficial? And is it really better than olive oil? Here, experts weigh in on where butter fits in a healthy diet and how much we should be eating.

Rethinking butter.
Throughout the 1920s and 1930s, when a lot of nutrition research was focused on women and children, butter was touted as a protective food for babies and children.

Starting in the 1960s, the American Heart Association recommended cutting back on saturated fat because it was linked to heart disease. Then in 1980, the USDA issued the first dietary guidelines which recommended cutting back on saturated fat, total fat and cholesterol.

“That idea has been at the heart of our nutrition policy for the last half century,” said Nina Teicholz, author of “The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet.” “That science has really now been overturned. There is no longer good evidence that saturated fat causes heart disease.”

A meta-analysis published in the American Journal of Clinical Nutrition in 2010 found no link between saturated fat in the diet and coronary heart disease, stroke or cardiovascular disease.

In March of this year, another meta-analysis in the journal Annals of Internal Medicine concluded the same: There is not enough evidence to support guidelines which advise limiting saturated fat to prevent heart disease. Plus, the authors noted that increasing intake of polyunsaturated fats like omega-3 and omega-6 fatty acids doesn’t help either.

Still, the fat in butter helps us absorb and utilize these vitamins in our diet, according to Libby Mills, a registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics. So adding a pat of butter to a cup of broccoli, for example, can be a healthy choice.   

Butter also contains conjugated linoleic acid (CLA), which some studies suggest may reduce a woman’s risk for colon and breast cancers. Yet CLA’s claim to fame is its harmful effect on cholesterol. While it does lower LDL (bad) cholesterol, it may also lower HDL (good) cholesterol.

Butter contains vitamins A, E, D and K, which are all fat-soluble vitamins that get stored in the body. Yet you would have to eat large quantities in order for butter to be a significant source of the nutrients.

What's more, the effects of saturated fat on cholesterol are well known.

“While saturated fat does slightly raise good cholesterol (HDL), it also raises to a greater extent LDL,” Mills said.  

Butter vs. carbs
It’s true, butter is linked to high cholesterol, clogged arteries, atherosclerosis, and obesity, but these are actually due to eating carbohydrates which increase blood glucose levels and in turn, raise insulin, said Grant Petersen, author of “Eat Bacon, Don’t Jog: Get Strong. Get Lean. No Bullshit.”

“It isn’t as though butter is some superfood full of nutrients,” Petersen said. “Most of the problems that are blamed on butter are the cause of something other than butter. And in most cases it’s carbohydrates.”

Saturated fats don’t actually go straight to the arteries, as we’ve been lead to believe. Instead, high insulin levels and high triglyceride (a type of fat) levels in the liver are key factors.

When you have high circulating insulin in your blood, you can’t access fat for fuel and so the calories are storied as triglycerides in the fat cells. The triglycerides then deposit cholesterol into the arteries, leading to clogged arteries. Blood tests can screen for both triglycerides levels and insulin levels.

“Butter is healthy fat,” Petersen said. “It sounds so outrageous to say that because we have been told for decades that it’s unhealthy fat. But unsaturated fat is not unhealthy provided you have low insulin levels in your blood.”

So suffice to say, if your diet is healthy overall, adding some butter won’t kill you.

How much butter is best?
Monounsaturated fats like those found in olive oil, avocado, nuts and seeds and polyunsaturated fats like those found in sunflower oil and fatty fish are touted as heart-healthy fats that should be included in our diets. In fact, a recent study out of Harvard School of Public Health found that swapping 5 percent of calories from saturated fat with polyunsaturated fat sources can lower the risk for heart disease by 9 percent.  

Yet Teicholz argues these fats are no better than the saturated fat in butter. Plus, vegetable oils can be worse because when they’re heated, they can produce toxic chemicals.  

“They’re unequivocally bad for health,” she said.

The USDA Dietary Guidelines recommend saturated fat be less than 10 percent a day, while the American Heart Association says it should be even less, between 5 and 6 percent.  

What’s more, the USDA Dietary Guidelines Advisory Committee are considering lowering the saturated fat recommendations even further when the new guidelines are released in 2015 .

“Our experts are going in the complete opposite direction of the science,” Teicholz said.  “Butter is a wonderful, delicious food and it’s a part of a healthy diet. There’s no reason to avoid it.”

Nutrition experts agree, like all delicious food, butter should be used in moderation.

“Be mindful of how much you’re using,” said Kelly Pritchett, a registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics. “I don’t think this is a free ticket to use butter excessively.”

Julie Revelant is a health journalist and a consultant who provides content marketing and copywriting services for the healthcare industry. She's also a mom of two. Learn more about Julie at revelantwriting.com.