Good news for cheese lovers
Yes, dairy is part of a Mediterranean-style diet. Of the nine points in a MedDiet score, most are what we like to call "more than" points: eat more vegetables, eat more fish, etc.. Dairy is one of the "less than" points, like red meat: ideally no more than about 7 ounces of dairy products - and best if they are fermented dairy such as cheese, sour cream, or yogurt - per day, on average.
We know that the Mediterranean-style diet, as an overall dietary pattern, helps to prevent heart disease. As with other points in a MedDiet score, researchers in France looked at teasing out whether there is a specific connection between dairy consumption and heart disease (Brit J Nutr 2022;127;752-762).
To find out they turned to the prospective study known as the NutriNet-Sante, a large-scale, long-term study that began recruiting participants of at least 18 years of age in 2009. Instead of collecting dietary information by asking participants to estimate how much of a particular food they eat on a weekly basis, the participants report what they ate in the previous 24 hours on three non-consecutive, randomly-selected days in a two-week period. If a participant didn't know exactly how much of a particular food they ate, calibrated pictures of the specific food helped them estimate. This makes the study's dietary information remarkably accurate.
The researchers totaled the participants' overall dairy intake and also summed the different types of dairy: milk, cheese, yogurts, curd cheese, and "petit suisse" (a French food somewhat similar to yogurt). They did not include milk products with more than 12% of calories from sugar, as they are regarded as desserts, and butter and cream are considered fats.
The participants are regularly prompted to report any health issues, and when appropriate those running the study acquire the participants' health records to confirm.
In January 2019 the authors excluded data from any participant who had reported having a heart condition upon recruitment, then compared the dairy intake of those who experienced a heart attack, stroke, or other cardiovascular event with those who did not.
Somewhat surprisingly, overall dairy intake had no significant association with heart disease.
That said, those who consumed the most fermented dairy, including yogurt, cheese, and fermented milk, were 19% less likely to experience cerebrovascular disease (think stroke or hemorrhage in the brain) than those who consumed the least fermented dairy.
In fact, the authors estimate that each additional 100 grams (about 3.5 ounces) of fermented dairy per day conferred an additional 9% lower risk of cerebrovascular disease.
What this means for you
Good news for those who like cheese, certainly. This doesn't mean you have license to eat all you want or any kind you want, however. Choose lower-fat cheese and yogurt and bear in mind that moderation is key.