Wholesome prevention: Full-fat dairy can reduce diabetes risk?

Here’s a surprise: researchers from the Harvard School of Public Health reported that higher intake of whole fat dairy products correlated with a lower incidence of type II diabetes in adults aged 65 and older.

Published in yesterday’s Annals of Internal Medicine, the study analyzed data from a cohort of approximately 3,700 Medicare-eligible patients. Subjects with the highest levels of trans-palmitoleic acid exhibited a 60 percent lower incidence of diabetes compared with those who had the lowest levels. While the amount of trans-palmitoleic acid in the bloodstream reflects numerous factors, levels were linked to the quantity of whole fat dairy — especially whole milk — consumed by the study’s subjects.

However, it is not certain that this trans fat plays a direct role in reducing the metabolic precursors to diabetes, or is “a marker for some other, unknown protective constituent of dairy or other ruminant foods,” says lead study author Dr. Dariush Mozaffarian.

ACSH’s Dr. Elizabeth Whelan notes that the study findings are strongly counter-intuitive because “these dairy products are high in fat and calories. And we know that obesity is a risk factor for type II diabetes.”

Although intrigued by the findings, ACSH’s Dr. Gilbert Ross believes it is important to keep perspective on them, reminding us that “you cannot establish causation from a retrospective or observational epidemiological study. Before anyone can safely recommend increasing whole milk consumption, this study’s results need to be replicated by other groups and should be followed up with a bigger and, if possible, randomized study. Even if these findings are valid, they only apply to a specific population — adults 65 years and older. So guzzling more whole milk is not for everyone.”