Move over, omega-3s. There's a new fatty acid in town that might make you healthier. Something more closely associated with creamy pleasure than with fish burps.
Trans-palmitoleic acid, a fatty acid that circulates at higher levels in the blood of those who consume lots of full-fat dairy products, may protect against diabetes, according to a study published Monday in the Annals of Internal Medicine. That surprising finding may fly in the face of much nutritional advice that warns us against consuming too much whole milk, cheese or other sources of animal fat. But it comes from a study of 3,736 adults participating in the long-running Cardiovascular Health Study.
It also proceeds from a suspicion that researchers have had for a while, but found difficult to prove: that the fatty acid palmitoleate, which humans produce in their liver and fat, and consume in dairy fats, may play a complex role -- beneficial and harmful -- in regulating metabolism. By measuring just the palmitoleate that came from consumption of dairy fats, researchers were able to discern the side of this fatty acid that may contribute to good health.
Although trans-palmitoleic acid represented only 1% of the fatty acids circulating in subjects' blood, the authors of the study found that those with the greatest volume of it in their bloodstreams tended to report the highest consumption of full-fat dairy foods, that they tended to have less fat around their midsection, that they were unlikely to have developed insulin resistance, and that they were least likely to develop Type 2 diabetes in the course of the study.
"The magnitude and the robustness of these relationships were both substantial," the authors wrote. Although they acknowledged that the consumption of dairy fat may be a double-edged sword, it does seem to do one thing that is at least indirectly helpful to metabolic function: It raises levels of trans-palmitoleic acid.
The findings "suggest that efforts to promote exclusive consumption of low-fat and nonfat dairy products ... may be premature." They added that, if further research demonstrates that dairy fat actually promotes better metabolic function (a causal link that goes beyond the association found here), "this fatty acid is a candidate for potential enrichment of dairy foods or supplementation."