Could Cabbage and Broccoli Help in the Fight Against Alzheimer’s?

Apr. 28, 2014

According to a study published in the journal Nature Communications, consuming cruciferous vegetables like cabbage, cauliflower and broccoli may help reduce the levels of the bad tau proteins that accumulate in the brains of Alzheimer’s patients. These foods contain a chemical that activates the protein Nrf2, which plays several important roles in maintaining cellular health. The article, published by University of Rochester School of Medicine and Dentistry researchers, shows that Nrf2 helps promote degradation of the bad tau proteins, potentially preventing brain cells from developing neurofibrillary tangles a prominent feature of Alzheimer’s disease.

broccoli and cabbageBrain tau tangles and amyloid plaques are two hallmark features of Alzheimer’s disease. Whereas much has been talked about amyloid plaques and their contribution to Alzheimer’s disease onset and progression, studies addressing neurofibrillary tangles and their therapeutic implications are lagging behind. Neurofibrillary tangles are formed by the accumulation of tau proteins, leading to aggregates or tangles in the brain. As such, the clearance of the tau proteins could be potentially therapeutic.

Nrf2 is widely studied in the context of cellular stress and is known to be a master regulator of stress responses. Activation of Nrf2 has been previously implicated in facilitating learning and improving memory in a mouse model of Alzheimer’s disease, but its mechanism in mitigating Alzheimer’s disease has not been tested until now.

The authors show for the first time that Nrf2 turns on another protein, NDP52, which binds to the bad tau proteins and targets them for degradation. This prevents them from building up and forming tangles. Using a mouse model, study authors reported gradual accumulation of bad tau proteins when Nrf2 was absent. Furthermore, they demonstrated that Nrf2 strongly stimulates NDP52. NDP52, in turn, was shown to bind directly to tau proteins collected from brain samples of Alzheimer’s patients, mediating their destruction.

The study was conducted by researchers in the Department of Anesthesiology and the Department of Environmental Medicine, Lung Biology and Disease Program at the University of Rochester School of Medicine and Dentistry. The lead author is Chulman Jo, Ph.D., from the lab of Gail V.W. Johnson, Ph.D. in the Department of Anesthesiology. Additional authors in the study were Soner Gundemir, Ph.D., Susanne Pritchard, and Youngnam N. Jin, Ph.D., from the Department of Anesthesiology, and Irfan Rahman, Ph.D., from the Department of Environmental Medicine, Lung Biology and Disease Program.

The study comes hot on the heels of the broader Rochester Aging Study, which discovered novel blood-based biomarkers that are indicative of Alzheimer’s risk. Alzheimer’s disease is notoriously difficult to treat in the late stages when behavioral symptoms have already started to manifest. Hence, detecting an individual’s risk early on and halting the disease in a preliminary stage is extremely important. With the potential to detect the disease early much closer to a reality, a thorough understanding of early disease mechanisms presents an important opportunity for therapeutic intervention. This paper addresses one strategy for preventing the buildup of culprit tau proteins in the brain and provides insights about the efficacy of using Nrf2 activators for Alzheimer’s disease onset and treatment. In other words, continue consuming (or start eating) your cabbage and broccoli.