A Cardiologist Explains Which Health Food Fads Are Actually Good for You - Fortune

Fat was the enemy — until it was rather abruptly usurped by sugar. Now nuts and whole-milk dairy products are making a comeback, while artificial sweeteners and sugar-laced low-fat snacks and drinks are viewed with a sudden suspicion.

If you’re experiencing whiplash, you’re not alone. “There is widespread chaos in the world of nutrition,” says Andrew Freeman, the director of cardiovascular prevention and wellness at National Jewish Health in Denver. “It seems recommendations swing back and forth all the time.”

In part, this is because nutrition is a slow and constantly evolving science. Well-designed studies, which ideally include a long duration time, a large sample size, and require participants to stick to a strict diet, are difficult and time-consuming to execute.

This lack of clarity is exacerbated by the media, who thrive on highlighting the radical and new at the expense of more nuanced and gradual shifts, and Big Food, which works to influence the language used in federal recommendations and frequently takes advantage of consumer confusion to push new products. Take cholesterol. The latest dietary guidelines from the United States Department of Agriculture, released in 2015, removed the 300-milligram daily limit on cholesterol. Many media outlets jumped on the change to craft dramatic headlines (such as “Cholesterol in food not a concern, new report says”), while the egg industry rushed to interpret the move as: eat as many eggs as you want!

This, according to Freeman, is a gross misreading. Yes, the new guidelines remove a daily cholesterol limit, but they also state that “individuals should eat as little dietary cholesterol as possible.”

To maintain heart health, restricted cholesterol intake is still better, he says.

And that’s just one example. In an effort to cut through all the noise and hype around what constitutes healthy eating Freeman, along with 11 other researchers, analyzed nearly 150 nutrition studies to determine which food fads are backed by science, and which are not. Their results are compiled in a review, published on Monday in the Journal of the American College of Cardiology.

Here’s where they came down on everything from gluten to juicing to the benefits of acai berries.

Cooking oils

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Coconut is having a moment. Put its name before water or milk, and the product suddenly achieves trendy “superfood” status. This is also true for coconut oil, which is popping up in recipes from soups to muffins.

When it comes to heart health, however, you’re probably better sticking to olive oil, which has been shown over multiple studies to decrease the likelihood of heart disease. For coconut oil, which is high in saturated fat, the jury’s still out — there’s simply not enough data, Freeman concludes, to understand its impact. Per the review, “Current claims of documented health benefits of the tropical oils are unsubstantiated and use of these oils should be discouraged.”

Antioxidants

The term has gained a lot of traction of late. Acai, a red fruit that grows in South and Central America, became particularly trendy after being touted for its antioxidants and corresponding health benefits on “The Oprah Winfrey Show.”

Despite the fruit’s now mythical qualities, you’ll get just as many benefits from less exotic berries. In other words, go ahead and eat acai, but if the fruit isn’t handy, grab some blueberries, raspberries, or strawberries instead, says Freeman. The impact is the same.

Meanwhile, there’s no evidence antioxidant supplements benefit heart health, says Freeman. Instead, antioxidants are best consumed via fruits and vegetables, particularly colorful fruits and leafy greens.

Nuts

As evidence of sugar’s deleterious impact on heart health grows stronger, once shunned high-fat foods are making a comeback. First in line? Nuts, which are high in calories but also heart-healthy fats. Freeman says go ahead and add them to the snack rotation, but “beware of consuming too many, because nuts are high in calories,” he says. “A lot of people are eating loads — you can easily eat several hundred calories in one sitting, so people need to be careful that they don’t overdue it.”

Juices

Juice cleanses are fun to Instagram, but their impact on heart health is less clear. Primarily, this is because juicing makes it easy to consume a large amount of calories and natural sugars before getting full (think about how much more quickly you can drink a glass with the juice from four apples than actually eat four apples). While juices can lead to weight loss and other heart benefits if they replaces foods high in saturated fat and added sugars. “Until comparative data become available,” the review concludes, “whole food consumption is preferred, with juicing primarily reserved for situations when daily intake of vegetables and fruits is inadequate.”

Gluten

Aside from the estimated 6% of the population that has celiac disease or gluten-related sensitivities, there is little evidence that gluten promotes weight gain or other negative health effects. “There’s a lot of controversy, not a lot of data,” says Freeman.

For those without a gluten sensitivity, he recommends focusing on eating unprocessed grains rather than avoiding gluten altogether. Avoiding gluten is not always synonymous with healthy eating. Take gluten-free pizza: removing the gluten doesn’t remove the carbohydrates and the cheese.

The bottom line:

It’s not sexy, but the research shows that the key to heart health isn’t revolutionary: eat lots of fruits, vegetables, whole grains, and legumes, and a moderate amount of nuts, lean meats, vegetable oils, and low-fat dairy products. Despite dramatic headlines and the marketing efforts of Big Food and supplement companies, there is no “superfood” magic bullet that will erase the effects of an unhealthy diet or lead to weight loss on its own. Instead, healthy eating is about moderation, says Freeman. A boring message, maybe, but one backed by science.