A comprehensive study spanning 25 years monitored the health of 27,670 individuals, leading to the diagnosis of dementia in 3,208 participants. Notably, those without a genetic predisposition to Alzheimer's who consumed over 50 grams of full-fat cheese daily exhibited a 13% to 17% reduced risk of developing the disease. This protective association was absent in individuals carrying genetic risk factors.
Additionally, participants who ingested more than 20 grams of full-fat cream each day demonstrated a lower overall risk of dementia, with reductions ranging from 16% to 24%. Interestingly, no significant relationships were identified regarding low-fat or high-fat milk, or fermented versus non-fermented dairy products.
Implications for Dietary Guidelines
The findings challenge traditional nutritional advice, which has often promoted low-fat dairy options for cardiovascular health. This is crucial, as both heart disease and dementia share similar risk factors, including hypertension, diabetes, and obesity.
When combined with previous research, these findings suggest that cheese consumption may correlate with a decreased risk of heart disease, indicating that full-fat dairy may not inherently elevate cardiovascular risk. While several studies have investigated the links between dairy intake and brain health, the results remain varied.
Variability in Study Outcomes Across Populations
Research indicates that Asian populations are more likely to report cognitive health benefits from dairy consumption compared to European studies, possibly due to lower average dairy intake in Asian countries. For instance, a Japanese study noted a decrease in dementia risk linked to cheese consumption, although overall intake levels were quite minimal, and the research was financed by a cheese company. Conversely, another government-funded Japanese study found no protective effects from cheese.
Long-term European studies have also shown positive results. A Finnish study involving 2,497 middle-aged men over 22 years indicated that cheese was the only food associated with a 28% lower dementia risk.
Dietary Patterns and Cognitive Function
Other dietary elements appear to influence cognitive health as well. Higher intake of milk and processed red meat was linked to poorer cognitive performance, while regular fish consumption correlated with better outcomes. A large UK study following nearly 250,000 participants found that those who consumed fish two to four times weekly, fruit daily, and cheese weekly had a lower risk of dementia.
However, these studies have limitations, primarily due to reliance on self-reported dietary habits, which can be affected by memory changes. To address this, Swedish researchers implemented two key strategies.
Addressing Early Dementia Indicators
Initially, they excluded participants diagnosed with dementia at the study's outset. They then recalculated results after removing individuals who developed dementia within the first ten years. This approach did not involve starting anew but rather refined the results using a subset of participants who maintained cognitive health for a longer duration.
This methodology accounts for subtle behavioral changes that can occur in the early stages of dementia, which may influence diet. By focusing on participants who remained cognitively healthy, the researchers minimized the risk of early-stage changes skewing the results.
Food Substitution and Overall Dietary Context
Another critical consideration is whether substituting cheese or cream for red or processed meats could explain some benefits observed. The Swedish study found no connection between full-fat dairy and dementia risk among participants whose diets remained stable over five years.
Ultimately, it's essential to view foods within the context of overall dietary patterns. Diets like the Mediterranean diet, known for its association with lower dementia and heart disease risks, incorporate cheese alongside a variety of vegetables, fish, whole grains, and fruits.
Lifestyle Factors and Their Impact
In the Swedish study, individuals consuming more full-fat cheese and cream tended to be more educated, less overweight, and had lower incidences of dementia-related conditions such as heart disease, stroke, hypertension, and diabetes. These factors independently contribute to reduced dementia risk.
This suggests that higher cheese consumption often aligns with healthier lifestyles rather than excessive calorie intake or poor metabolic health.
Conclusions from the Evidence
Overall, the evidence does not support the notion that full-fat dairy consumption leads to dementia, nor does it confirm that fermented dairy products consistently provide protection. Full-fat cheese is rich in several nutrients beneficial for brain health, including fat-soluble vitamins A, D, and K2, as well as vitamin B12, folate, iodine, zinc, and selenium, all of which are vital for neurological function.
However, the data do not endorse consuming large quantities of cheese or cream as a safeguard against dementia or heart disease. The prevailing advice emphasizes that balanced diets, moderation, and overall lifestyle choices are far more significant than any single food item.