Can beer really improve concentration and reduce the risk of dementia?

This blog is co-authored by Katie Nicol & Emilie Combet

Dementia and cognitive decline are growing concerns in today’s ageing society. Although we do not yet have the full picture of how cognitive decline initiates and progresses, it is thought that diet may be a risk factor. This opens an avenue of research testing foods and diet as a tool for cognitive decline prevention and possibly management. Previous blog posts have already investigated the science behind the superlative headlines linking food and drinks and brain health/dementia. Here, The Mirror, The Express and The Irish Post all capitalised on a finding from a recent study conducted in Japan, highlighting the potential positive effects of drinking beer and titled their article “Drinking beer could improve your concentration and reduce risk of dementia, study claims”. We will evaluate this claim by looking at the study and how it was reported by the newspapers.

What did the researchers do?

One hundred adults aged 45-69 years were given a supplement containing a small compound found in the hops used to make beer (hops give beer its slightly bitter aroma), known as mature hop-derived bitter acids (MHBA) or a placebo (a substance that has no effect) to consume daily for 12 weeks. Participants were not habitual beer drinkers and were self-reported as having cognitive decline classed as worsening or more frequent memory loss or confusion, but notably, were excluded from participation if they had suspected dementia based on their Mini-Mental State Examination (MMSE) score.

The participants completed a variety of tasks to assess their attention, cognition and memory at the start and end of the study. No dementia risk was defined per se by the study.

What did the researchers find?

After taking the MHBA supplement (35mg, daily), the participant’s average score in one of the tests (the Symbol Digit Modalities Test, or SDMT), which is used to assess a person’s divided attention performance, improved by just ~3.1% compared to ~1.7% in those taking the placebo. This is a very small difference which was labelled “significant” using a statistical test – but it does not mean that this would make a discernible change to the lives and experiences of the testers “in real life”. The SDMT score was also one of four tests that were carried out to assess attention performance; when all the tests assessing attention were added together, there was no difference in the total scores between MHBA and placebo groups.

Changes in memory performance also did not differ between those taking the MHBA supplement and the placebo, suggesting that the supplement does not improve memory.

How well does the media describe the study?

The Mirror, the Express and the Irish Post all published articles with headlines claiming that drinking beer could 1) reduce your risk of dementia and 2) improve your concentration, but these are not accurate statements. The study did not calculate a dementia risk. The study did not look at the effect of drinking beer either; instead, the participants took a supplement that contained MHBA, a small molecule used to flavour and stabilise beer. Beer does not contain levels of MHBA similar to the supplements used in this study – in fact, only a median of 24mg of MHBA can be found in a standard pint of lager. To consume the same amount of MHBA as was used in the study, a person would need to consume one and a half pints (or 750mL) of lager, equivalent to ~270 calories and above the recommended limit of 14 units per week. Therefore, any possible benefit should be considered against the risks of exceeding the recommended limit.

Typical  coverage was along the lines of the Irish Post: “Beer is not only good for your brain; it could actually improve concentration levels and speed up thought processes”. These are overstatements and risk the spread of misinformation. None of the articles included quotes from independent experts on dementia or nutrition. However, the Express did list NHS recommendations for reducing the risk of dementia, one of which is limiting alcohol consumption.

All three articles ended with a statement that MHBA supplementation may also improve energy metabolism in people with overweight, indicating that it may also help the reader to lose weight. This is in reference to a totally different study conducted by the same research group; participants consumed a beverage (not beer; less than 20kcal and no alcohol) containing 35mg MHBA daily for 12 weeks. Researchers found that visceral and total fat areas decreased in both MHBA and placebo groups, with a slightly greater effect in the intervention group after 12 weeks. However, this study did not measure metabolism, contrary to what was reported in all three newspaper articles.

Other things to keep in mind

Aside from the media reporting, the research study has limitations that need to be considered carefully. First of all, the participants were already experiencing self-reported cognitive decline – so we do not know whether the same results would be seen in those diagnosed with dementia. Self-reported decline in cognition is very subjective – as people may experience this differently depending on their social interactions, or leisure and employment activities, for example. The fact that the researchers are not transparent in detailing how the number of participants (the sample size of 100) was selected is also important, as it is not clear whether it is a sufficient number to test the hypothesis that the MBHA can have an effect on concentration or mental performance.

The study takes place over a relatively short period (3 months) and therefore cannot evaluate whether the supplement prevented age-related cognitive decline per se. Moreover, the MHBA supplement is consumed with no further control to the habitual diet, which can be a large confounding factor. With the research conducted in Japan, with a diet and lifestyle radically different from the UK, it is unclear whether adults in other countries would respond to the MHBA supplements in the same way.

Finally, the study was not only funded by a drink company looking to develop a line of beverages that will be marketed to improve cognitive function but also co-authored by a company employee. The company will benefit from the endorsement brought by the reporting of the study; there is therefore a conflict of interest in shedding a positive light on the ingredient MHBA, in the research paper and any associated press releases. Readers should take this into account when reading the study, which is available open-access.

Useful links:

• https://www.drinkaware.co.uk/
• https://www.nhs.uk/conditions/dementia/about/
• https://www.drinkaware.co.uk/
• https://www.nhs.uk/conditions/dementia/dementia-prevention/
• https://researchtheheadlines.org/2016/05/30/weekly-curry-unlikely-to-delay-dementia/