On the 8th of September, a exciting study by Collins et al., (2013) was released which claimed that fish oil can help to protect against dementia in alcohol abusers. Previous research has found that excessive alcohol consumption causes a significant rise in cell inflammation and death, which can lead to dementia. In the present study, Collins et al exposed rat neurons to excessive alcohol (equivalent to more than 4x legal driving limit), and some were also exposed to DHA (omega-3 docosahexaenoic acid, a compound found in fish oil). Quite amazingly, the neurons which were exposed to both alcohol and DHA showed approximately 90% less inflammation and cell death than the neurons exposed to alcohol alone.
Despite the great promise this study shows, caution is advised when interpreting the results. Although the study clearly shows that fish oil can protect against the effects of alcohol, there is only mixed evidence to suggest that fish oil can protect against dementia. Barberger-Gateau et al., (2002) performed a 7-year longitudinal study on the effects of meat and fish on the risk of dementia, and found that the participants who consumed fish or seafood at least once a week were significantly less likely to develop dementia. In 2007, Barberger-Gateau et al., supported their previous results with a study of over eight thousand participants which showed that frequent consumption of fish and omega-3 rich oils can protect against dementia and Alzheimer’s disease. Van de Rest et al., (2008) however, found that a 26-week course of supplements led to little difference in cognitive performance in a cohort of elderly participants. A Cochrane Review (2012) also found that, in a cohort of over three thousand healthy, elderly participants, there was no difference in cognitive performance between the participants taking fish oil supplements, and those taking placebo supplements. A Cochrane Review is an independent, not-for-profit clinical trial which often allows for a realistic review of what scientific evidence currently shows. On this basis, it seems that fish oil may not be as successful at warding off dementia as it seems.
Therefore, the results of Collins et al., (2013) may not be as promising as they seem. It may be for instance, that although fish oil prevents cell inflammation and death, alcohol causes other difficulties which then lead to dementia. As noted by Cheon, Joe and Kim (2012), the link between alcohol and dementia is still unclear, and unforeseen mechanisms may still cause alcohol-related dementia to occur, even after taking supplements which prevent cell death. It must also be remembered that this study was performed on rat neurons, and although many animal studies lead to similar results in humans, it is not a perfect science. The authors were also very keen to point out that taking fish oil supplements whilst still consuming excessive alcohol is not enough to stave off dementia. In previous studies (e.g. Collins et al., (2009), the authors have found that moderate alcohol consumption (two drinks per day for men, and one drink per day for women) can be protective against cognitive decline, and they recommend this as a more effective treatment than simply consuming fish oil. So despite the promise of the former study, further research needs to be conducted using human trials before a treatment for alcohol-related dementia using fish-oil can be recommended.