If you're worried about your health, you may be reaching for low-fat dairy products when you go shopping. After all, that's what the US Dietary Guidelines and many health organizations recommend. Well, it turns out that there isn't much evidence to back those recommendations up. And now two new studies out this week call into question the wisdom of that advice.
The first study looked at the relationship between the development of diabetes and dairy fat levels in the blood in participants from the Nurses' Health and Health Professionals Follow-Up Study. The people in these studies had their blood tested and were then followed for decades. The researchers found that when they compared the people with the lowest levels of dairy fats in their blood with the people who had the highest levels -- they actually saw that the people in the high-fat group had a more than 40 percent lower risk of developing diabetes. It's not known exactly why this would be, but one theory is that dairy fats can help improve the body's sensitivity to insulin (in diabetes the body becomes less sensitive to insulin).
The second study looked at the relationship between dairy consumption and the likelihood of becoming overweight or obese in over 8,000 people from the Women's Health Study. Participants in this study completed a questionnaire about how much and how often they ate different types of dairy foods and were then followed, on average, for over a decade. The researchers found that people who said they ate the highest fat dairy products actually had an 8 percent lower risk of becoming overweight or obese than the people who ate low-fat products. This seems counterintuitive, because high fat dairy products have more calories, but it may be that the sensory experience of eating high fat dairy products is more satisfying and actually leads to people eating less calories overall. In addition some low-fat products are actually loaded with sugar -- which means they end up having more calories than the full-fat versions.
So while the advice to choose low-fat dairy is based on the idea that we need to reduce the amount of saturated fat in our diets (the kind of fat found in animal products), these studies illustrate that sometimes just focusing on a single nutrient rather than thinking about a whole food can lead us astray.
The bottom line: If you're not eating dairy, don't start because of these studies. If you're already a dairy consumer, these and other studies suggest you don't stress over eating the high-fat versions. Eat what you like best, probably the good stuff -- as close to the natural version as you can get. And of course, as with all things, eat in moderation.