Health experts have long recommended avoiding full-fat dairy because it is high in saturated fats, which in excess can raise cholesterol and the risk for heart disease. It is also higher in calories than reduced-fat versions, potentially increasing the chances of gaining weight.
But these recommendations were based on older studies that found links between diets high in saturated fats and heart disease but did not look into the health effects of dairy specifically.
We’ve been telling people to prioritise low-fat dairy products “based on almost no evidence” showing they’re better for health, said Dr Dariush Mozaffarian, a cardiologist and the director of the Food Is Medicine Institute at Tufts University, US.
When you look at the more recent body of evidence on how dairy influences health, you’ll find that the study results are “all over the map”, said Richard Bruno, a professor of human nutrition at the Ohio State University, US.
Research finds
In one study from October that included about 74,000 adults in Norway, for instance, researchers found that those who consumed the most whole milk were 7 per cent more likely to die of cardiovascular disease than those who consumed the least.
But another study from September, which followed about 3,100 adults in the US for 25 years, concluded something different. Those who consumed the most full-fat dairy (milk and cheese) had a 24 per cent lower risk of developing an early sign of heart disease (coronary artery calcification) than those who consumed the least full-fat dairy.
A small clinical trial from 2016 found that following a blood-pressure-lowering diet that incorporated full-fat dairy reduced blood pressure just as well as a version of the diet using low-fat dairy.
In a 2020 analysis of 28 studies, researchers found that children who consumed whole milk did not tend to gain more weight than those who consumed low-fat milk. An older study from 2014 on adults concluded the same.
A group of nutrition experts from around the world wrote in The American Journal of Clinical Nutrition in May that most of the recent research suggests that when it comes to cardiovascular health, low-fat dairy does not seem to be preferable to full-fat dairy, or vice versa.
Dairy fat may be special
We don’t know exactly why full-fat dairy is sometimes linked with better health, Dr Mozaffarian said.
One theory is that most dairy products like milk, cheese and yogurt contain not just saturated fats but other types of fats called polar lipids. There’s still a lot we don’t know about how polar lipids influence health but some animal studies have suggested that they may lower inflammation and reduce the amount of cholesterol absorbed in the gut.
Another explanation has to do with the complex structure and interaction of dairy’s other components (called the food matrix). Cheese, for instance, is often high in saturated fats but it also contains beneficial bacteria, protein, vitamins and many other substances that might change how the body digests the fat, said Benoit Lamarche, director of the Nutrition, Health and Society Center at Laval University in Quebec, Canada. These might help prevent, or at least mitigate, the harms of saturated fat.
Butter, however, doesn’t seem to offer these health benefits. It is composed mostly of saturated fats, so when consumed in excess, it can raise bad cholesterol, increasing the risk for cardiovascular disease.
One cup of whole milk contains nearly twice the calories as one cup of skimmed milk, but because it does a better job of filling you up, you might consume fewer calories from other foods, said David Jacobs, a nutrition epidemiology researcher at the University of Minnesota, US.
Bottom line
The experts we spoke with agreed that there is not enough evidence to recommend one type of dairy fat over the other. Bruno said that instead, people should eat whatever type they prefer — as long as it fits into their diet.
And there are good reasons to eat it. Most dairy products contain protein, Vitamin D, calcium and — in the case of fermented dairy products like yogurt, kefir and some cheeses — gut-friendly bacteria. Consuming these nutrients through dairy, especially if you aren’t getting them from the rest of your diet, is “a big win”, Bruno said.
Just keep in mind that not all dairy products are healthful. Butter is extremely high in saturated fats and can put your heart at risk, and processed dairy products like chocolate milks and ice creams can be loaded with added sugars, which in excess can lead to health issues such as obesity and type 2 diabetes.
If dietary guidelines end up elevating full-fat dairy, don’t interpret that to mean that all foods containing saturated fats are harmless, Jacobs said. Processed meats and many baked goods and fried foods, which are high in the fats, can be harmful to health.
NYTNS