Study links consumption of full-fat cheese to lower risk of dementia

A new study published by Du and colleagues observed that people who reported a high intake of high fat cheese in the 1990s had lower risk of developing dementia around 25 years later than people who did not eat cheese.  While these are interesting data, this type of study cannot determine whether this association of reduced dementia risk was caused by the differences in cheese consumption. One of the biggest limitations of this study is the cheese consumption as recorded from a food diary and interview at one time point 25 years before the analysis of dementia diagnosis. It is highly likely that diet and other lifestyle factors changed in those 25 years. Strong evidence from across the field indicate that healthy diet, exercise, and cognitively stimulating activities (education, challenging jobs and hobbies etc) can boost brain resilience to diseases that cause dementia. There is not strong evidence for any individual food protecting people from dementia.

I do not believe there is a causal link here, as this is an observational study rather than a randomized controlled trial. It is important to note that individuals who consumed more high-fat cheese and cream were, on average, better educated. This raises the possibility of residual confounding - whereby other 'healthy' characteristics associated with higher education, rather than the cheese or cream itself, may explain the lower dementia rates observed. 

We already know of several well-established and proven factors that reduce dementia risk, such as maintaining healthy blood pressure, managing weight, and preventing heart disease or stroke. These interventions should remain the priority, given their strong evidence base, rather than focusing on unproven dietary associations.