Editor's note: This popular story from the Daily Briefing's archives was republished on June 20, 2023.

Ice cream has typically been considered an indulgent dessert, but multiple studies have found that ice cream may be associated with various health benefits, David Merritt Johns reports for The Atlantic.

What the research says about ice cream's potential health benefit

Since the 1980s, researchers at  Harvard University  have collected "food-frequency questionnaires" and medical data from thousands of healthcare providers around the United States. In 2005, they released a  study  that looked at one cohort of that data, which followed men between 1986 and 1998.

The researchers found that a high dairy intake, especially a higher low-fat-dairy intake, was associated with a lower risk of diabetes. "The risk reduction was almost exclusively associated with low-fat or non-fat dairy foods," Harvard said in a news release.

Specifically, the study had found that men who consumed at least two servings of skim or low-fat milk each day had a 22% reduced risk of developing diabetes. And the study found the same risk reduction among men who had at least two servings of ice cream every week.

In another paper published in 2014, researchers looked at another dozen years of diet-tracking data and found that a "higher intake of yogurt is associated with a reduced risk" for type 2 diabetes, "whereas other dairy foods and consumption of total dairy are not."

But according to Dariush Mozaffarian, dean of policy at  Tufts University's nutrition school and a co-author of the paper, "[t]he conclusions weren't exactly accurately written. Saying no foods were associated — ice cream was associated."

In fact, Kevin Klatt, a nutrition scientist at  UC Berkeley, said the ice cream finding in the study was "more consistent" than yogurt's across the cohorts, a conclusion that Deirdre Tobias, an epidemiologist at Harvard and member of the advisory committee for the 2025 update to U.S. dietary guidelines, agreed with.

Similarly, Dagfinn Aune, an epidemiologist at  Imperial College London  and a peer reviewer of the paper, said the ice cream effect was "similar" in magnitude to, or "slightly stronger" than the effect found for yogurt.

The Harvard researchers suggested that some of the people in the study may have developed health issues, like high blood pressure or elevated cholesterol, and as a result, started eating less ice cream. But people without health issues didn't have a reason to stop eating ice cream, creating a "reverse causation" effect in which people at risk of developing diabetes wouldn't eat ice cream, rather than ice cream preventing diabetes.

To test this theory, Frank Hu, senior author on the study and future chair of Harvard's nutrition department, and his co-authors set aside dietary data collected following health diagnoses like high blood pressure or elevated cholesterol and redid their calculations. As a result, the ice cream effect was cut in half, though the researchers found it was still statistically significant and bigger than the low-dairy effect found in the 2005 study.

According to Mozaffaraian, the effects of yogurt and ice cream were still fairly similar. "Within the realm of statistical uncertainty, they're identical," he said.

Hu said his team felt confident about their findings on yogurt in part because prior clinical studies and research have supported the idea that probiotics found in yogurt improve metabolic outcomes. "For ice cream, of course, there is no prior literature," Hu said. Since the ice cream effect was diminished in the follow-up research, Hu said it's "much more plausible" that yogurt would help prevent diabetes more than ice cream.

However, other research has still found a health effect related to ice cream. In 2002, Mark Pereira, an epidemiologist at the  University of Minnesota, published a paper when he was an assistant professor at Harvard that looked at the emergence of heart disease risk among more than 5,000 adults on data that had been gathered since 1985.

They found that for the most part, dairy foods seemed to help prevent overweight people from developing insulin-resistance syndrome, a precursor to diabetes. Specifically, the researchers found that a "dairy-based dessert," which according to Pereira, mostly consisted of ice cream but also included foods like pudding, saw a 2.5 times greater risk reduction of developing insulin-resistance syndrome than what the researchers found for milk.

In addition, a study published in 2018 by Andres Ardisson Korat, a doctoral student at Harvard, found that eating half a cup of ice cream each day was associated with a lower risk of heart problems among diabetics.

According to an anonymous source who attended Ardisson Korat's presentation and spoke to The Atlantic, Ardisson Korat and his team "had done, like, every type of analysis — they had thrown every possible test at this finding to try and make it go away. And there was nothing they could do to make it go away."

Is ice cream actually good for your health?

There's no definitive answer for why research has found a health benefit to ice cream, but according to Johns, there are a "few points" in ice cream's favor.

First, ice cream's glycemic index, which measures how rapidly a food boosts a person's blood sugar, is lower than brown rice. "There's this perception that ice cream is unhealthy, but it's got fat, it's got protein, it's got vitamins. It's better for you than bread," Mozaffarian said. "Given how horrible the American diet is, it's very possible that if somebody eats ice cream and eats less starch … it could actually protect against diabetes."

Dairy advocates also often mention the "milk-fat-globule membrane," a triple-layered membrane that encases the fat within mammalian milk. Some  research  has suggested that dairy products where the membrane is intact — which includes ice cream — are more metabolically neutral than foods like butter where the membrane is lost during its churn.

According to Pereira, ice cream's health benefit has "been more or less replicated. Whether it's causal or not still remain an open question."

Pereira noted that people aren't always honest when asked about what they eat. His study from 2002 found that overweight and obese people reported eating fewer dairy-based desserts than other people. "I don't believe that the heavier people consume less desserts," he said. "I believe they underreport more."

"I think probably the ice cream is still reverse causation," Mozaffarian said. "But I'm not sure, and I'm kind of annoyed by that." Mozaffarian added that, had this been a patented drug, "you can bet that the company would have done a $30 million randomized controlled trial to see if ice cream prevents diabetes." (Johns, The Atlantic, 4/13)