Fish oil, when combined with epigallocatechin‑3‑gallate (EGCG—a polyphenol and antioxidant found in green tea), may affect chemical processes in the brain associated with Alzheimer’s disease, according to a study published in Neuroscience Letters. This study, which used an animal (mouse) model of Alzheimer’s disease, builds on previous research linking the disease to peptides (amino acid chains) called beta‑amyloids and laboratory studies suggesting that EGCG decreases memory problems and beta‑amyloid deposits in mice.
Researchers from the University of South Florida divided Alzheimer’s disease‑model mice into five feeding groups. During a period of 6 months, each group was fed one of five diets: fish oil only; high‑dose EGCG; low‑dose EGCG; low‑dose EGCG and fish oil; or a regular diet (control). The researchers observed that low‑dose EGCG alone did not reduce the Alzheimer’s disease-related chemical processes in the brain. However, the mice fed the combination of fish oil and EGCG had a significant reduction in amyloid deposits that have been linked with Alzheimer’s disease.
Upon examination of blood and brain tissues of the mice, the researchers found high levels of EGCG in the mice that were fed the combination of fish oil and low‑dose EGCG compared with those fed low‑dose EGCG alone. A possible explanation, according to the researchers, is that fish oil enhances the bioavailability of EGCG—that is, the degree to which EGCG was absorbed into the body and made available to the brain. This effect, in turn, may contribute to the increased effectiveness of this combination. Further research is necessary, however, to determine if the combination of fish oil and EGCG affects memory or cognition, and whether it might have potential as an option for people at risk of developing Alzheimer’s disease.
Giunta B, Hou H, Zhu Y, et al.. Fish oil enhances anti‑amyloidogenic properties of green tea EGCG in Tg2576 mice.. Neuroscience Letters..; ;471(3):134–138. .2009