[Health Channel/Comprehensive Report] Public health physician Cai Bingjian said on the Facebook fan page "Global Public Health Healthy Eating Lifestyle | Public Health Physician Cai Bingjian" that when it comes to "brain-boosting diets", one thing that is most easily overlooked is that what research usually looks at is not a certain magical food, but how the overall dietary pattern changes the way the body uses energy.
An interim analysis of a randomized crossover trial published in "Food & Function" in 2026 included 47 Spanish elders over 60 years old with mild cognitive impairment, with an average age of 73.1 years, and 42.6% were women. Each participant received three diets in varying order for 24 weeks each: a Mediterranean diet plus probiotics, a Mediterranean diet plus a placebo, and a low-fat diet based on World Health Organization recommendations; the full trial totaled 72 weeks.
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The focus of this report is not to directly compare "who is less likely to develop dementia", but to use targeted metabolomics to examine small molecule changes in plasma, and to see whether these changes change together with cognitive test scores.
What did the research reveal? Cai Bingjian explained that during the Mediterranean diet, studies have observed an increase in acetoacetate, an increase in metabolites related to pyruvate and citric acid cycle (TCA cycle), and a modulation of branched-chain amino acid metabolism, especially a decrease in isoleucine. These signals led the researchers to speculate that participants may have become more flexible in their ability to switch between fat and sugar fuels and use energy.
Changes in some metabolites were also associated with better cognitive scores. For example, increases in α-ketoisovaleric acid, α-ketoglutarate, and 2-oxoisocaproic acid are related to improvements in general memory, inhibitory control, and visuospatial reasoning; decreases in L-carnitine, isoleucine, and β-alanine are related to improvements in partial memory, attention, or working memory performance.
Cai Bingjian reminded that "getting better together" still does not mean that a certain metabolite directly improves cognition. The cognitive relationship is an association analysis in the trial data, and this is a preliminary interim metabolomic analysis of 47 people, which does not allow claims that the Mediterranean diet can prevent dementia or treat mild cognitive impairment.
The 150 people in the source notes, the 34% increase in metabolic elasticity, the 28% improvement in cognition, the 22% increase in BDNF, and the "improvement of brain glucose utilization efficiency" are not included in the full text of this article and therefore should not be used. This study also did not use respiratory exchange rate to directly measure metabolic elasticity, but instead inferred it from the metabolite patterns in blood.
Implications for daily diet
Cai Bingjian said that if you want to put your research direction into life in Taiwan, you can do it simpler first:
1. When eating out, add a portion of vegetables or beans first, and replace part of the refined starch with whole grains when possible.
2. Arrange fish, soy products and a small amount of nuts every week to provide more diverse sources of protein, and replace some high-saturated fat foods with unsaturated fats.
3. There is no need to adopt an extreme low-carb or ketogenic diet in order to "produce ketones"; this study tested a complete Mediterranean diet, not a single nutrient or supplement.
These are daily translations based on general healthy eating principles, and are not Taiwanese menus verified one by one in this article. Older adults who have weight loss, swallowing problems, kidney disease, diabetes medications, or other special nutritional needs still need to discuss them with a medical or nutrition professional.
The most worthwhile takeaway from this study is not that "what you eat can prevent dementia," but that the overall diet may change the body's energy metabolism network before cognitive results appear. This clue has scientific merit, but still needs to be confirmed by larger studies with complete follow-up and focused on clinical cognitive outcomes.
