June 30, 2026, 6:01 pm | Read time: 4 minutes
Can a healthy diet still influence the risk of dementia when the first signs of Alzheimer’s disease are already detectable in the blood? A large long-term study explored this question–with results that could offer new approaches to dementia prevention.
Diet with Anti-Inflammatory Effects Offers Benefits
Researchers from Sweden wanted to find out if a healthy diet can still influence the risk of dementia when the first biological signs of Alzheimer’s or other brain damage are present. The result: A diet with low inflammatory or anti-inflammatory effects was particularly associated with a lower risk of dementia, even in people whose blood values already indicated Alzheimer’s-type changes or other neurodegenerative processes.1
What the Study Examined and How It Was Conducted
For the study, scientists analyzed data from 1,865 people aged 60 and older who did not have dementia at the start. Participants were followed for up to 15 years. Using a detailed dietary questionnaire, researchers recorded eating habits and compared three dietary patterns: a Mediterranean-style diet, a generally healthy diet, and a diet with minimal inflammatory effects.
Additionally, blood samples were tested for three biomarkers that can indicate Alzheimer’s-type changes or other brain damage. Researchers then tracked which participants developed dementia–particularly Alzheimer’s dementia–during the study. In their analysis, they also considered factors such as age, gender, education, smoking, physical activity, body weight, and comorbidities.
Further Study Results in Detail
During the up to 15-year follow-up, 240 of the 1,865 participants developed dementia. Overall, it was shown: The higher the dietary quality, the lower the risk of dementia. The strongest correlation was found with a diet that had minimal inflammatory effects.
People with elevated blood levels of the Alzheimer’s biomarker “p-tau217” had up to a 29 percent lower risk of dementia with a consistently anti-inflammatory diet. A similar correlation was also observed with elevated levels of the biomarkers “NFL” and “GFAP,” which indicate damage to nerve cells or changes in support cells in the brain.
The results applied to both dementia in general and specifically to Alzheimer’s dementia. Moreover, people with elevated biomarker levels and an anti-inflammatory diet remained dementia-free longer on average and were less likely to develop dementia within the following ten years. Additional analyses confirmed the stability of the results.
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What This Specifically Means
The results suggest that a diet with minimal inflammatory effects could be particularly important for people with an increased biological risk for dementia. This supports the assumption that chronic inflammatory processes play a significant role in the development of Alzheimer’s and other neurodegenerative diseases. Foods such as vegetables, fruits, nuts, and whole grains, which are part of such a diet, have already been linked to better brain health in previous studies. Red and processed meats and sugary drinks should be largely avoided.
Furthermore, it was shown that not all healthy dietary patterns were equally associated with dementia risk. While the Mediterranean diet and other general recommendations showed benefits mainly in people with lower biomarker levels, an anti-inflammatory diet was associated with a lower risk of dementia even with increased biological risk.
Strengths and Weaknesses of the Study
The strengths of the study include the large number of participants, the long observation period of up to 15 years, and the use of modern blood markers that can detect early Alzheimer’s-type changes and other brain damage. Additionally, researchers compared three different dietary patterns directly for the first time.
However, the study also has weaknesses. The dietary information was based on questionnaires and may therefore be inaccurate. Furthermore, it is not clear which individual foods or nutrients were responsible for the observed correlations. As it is an observational study, it also cannot prove a cause-and-effect relationship between diet and dementia.