2026-07-21
A study published in the European Journal of Nutrition adds new evidence to the debate over how diet and other lifestyle habits may affect brain health before the first symptoms of Alzheimer’s disease appear. The research found that compounds from red wine reduced markers linked to Alzheimer’s pathology in a mouse model, with the strongest effects seen when the wine was dealcoholized, suggesting that polyphenols rather than alcohol may be driving the benefit.
The work was carried out by researchers including Juana I. Mosele, Jose Ignacio Manzano, Patricia Pérez Matute and Maria-Jose Motilva. It examined APP/PS1 mice, a widely used animal model of brain amyloidosis that develops amyloid-beta buildup similar to one of the main hallmarks of Alzheimer’s disease. The team focused on whether red wine and dealcoholized red wine could change amyloid accumulation in the hippocampus, a brain region involved in memory, and whether those changes were linked to shifts in metabolites found in feces, a way to explore the gut-brain axis.
The researchers began treatment when the mice were 2 months old and continued it until they were 8 months old, covering the period when amyloid-beta accumulation typically develops in this model. The animals were divided into groups that received either water, red wine, or dealcoholized red wine added to drinking water. One group received 1 milliliter of red wine per day, described by the authors as roughly equivalent to 200 milliliters a day in humans. Other groups received 1 milliliter or 2 milliliters a day of dealcoholized red wine, equivalent to about 200 milliliters and 400 milliliters a day in humans.
The red wine used in the study was made from the Graciano grape variety and contained 13.6% alcohol before dealcoholization. According to the researchers, both the regular and alcohol-free versions had similar polyphenol profiles. At the lower dose, mice received about 607 micrograms a day of total polyphenols from red wine and about 535 micrograms a day from dealcoholized red wine. At the higher alcohol-free dose, intake reached about 1,070 micrograms a day.
The main finding was that dealcoholized red wine lowered levels of Aβ40 and Aβ42, two forms of amyloid-beta associated with plaque formation in Alzheimer’s disease. The paper also reported that red wine reduced hippocampal amyloid-beta plaque accumulation in the APP/PS1 mice model. The authors said males appeared more sensitive to some of these effects than females, while females showed broader metabolic changes in response to treatment.
To measure these effects, the team analyzed soluble and insoluble amyloid-beta in hippocampal tissue using ELISA tests and also examined plaque deposits through immunohistochemistry. In parallel, they performed untargeted fecal metabolomics using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. That allowed them to compare metabolic signatures between untreated mice and those given dealcoholized red wine.
The metabolomic analysis showed clear differences not only between control and treated animals but also between males and females. In males, treatment was linked to enrichment of lipid-related and mitochondrial pathways. In females, the changes extended across a wider set of networks, including nucleotide metabolism, the tricarboxylic acid cycle and hormone metabolism. Two metabolites highlighted by the authors, guanosine and estradiol phenylpropionate, were correlated with Aβ42 levels in females, pointing to possible sex-specific mechanisms.
The study adds to a growing body of research around the Mediterranean diet, which has often been associated with lower risk of cognitive decline. The authors place moderate wine intake within that broader dietary pattern rather than treating wine as an isolated factor. They argue that plant-derived polyphenols may influence neuroinflammation, oxidative stress and amyloid processing partly through interactions with gut microbes and their metabolites.
At the same time, the findings remain preclinical and do not show that drinking wine prevents Alzheimer’s disease in people. The work was done in mice under controlled laboratory conditions, and the authors themselves describe the effects as dose-dependent and sex-dependent. They also point to dealcoholized red wine as especially relevant because it separates polyphenol exposure from alcohol intake.
That distinction matters because public health guidance has consistently warned about the risks tied to alcohol consumption, including cancer and liver disease. This study does not challenge those warnings. Instead, it suggests that some compounds naturally present in red wine may deserve further study as part of personalized dietary strategies or future nonalcoholic interventions aimed at brain health.
The researchers say their approach is novel because it tested the full mixture of polyphenols found in real red wine rather than focusing on a single compound such as resveratrol. They argue that this better reflects how foods are consumed in everyday life and may help explain why dietary patterns can matter as much as individual nutrients.
The paper also underscores how early these biological changes may begin. By starting supplementation before heavy amyloid buildup had taken hold, the study was designed to examine whether diet-related compounds could influence pathology during an early phase of disease development rather than after symptoms emerge. That timing fits with current interest in prevention and risk reduction long before dementia is diagnosed.
For now, the results are best seen as a step toward understanding mechanisms rather than a basis for clinical advice. What they offer is more detail on how polyphenol-rich foods or beverages might interact with metabolism and brain pathology through the gut-brain axis, and why sex differences may need more attention in future Alzheimer’s research.