Brain blog showcase 2021: Students “research the headlines”

At Research the Headlines we explore how research is discussed in the media. We try to add additional details to existing coverage, or help our readers get a clearer understanding of how new research might make its way from “lab to headline”. Through different activities, we also help others develop the skills needed to become more critical consumers of both research and media reporting; for example, via our How to “Research the Headlines” series and our “Rewrite the Headlines” workshops and competition for primary school children.

Many of our contributors also use the ideas behind Research the Headlines in their teaching. In one of his undergraduate courses, Alan Gow (Heriot-Watt University) has his students find a recent media article related to lifestyle factors and brain health. Their task is to describe the original research that report is based on in a manner accessible to non-experts, as well as evaluating the media coverage. A key aim of these “brain blogs” is to explain the important concepts and take home messages, and to highlight issues in interpretation either in the media report or the underlying research.

This week we’re showcasing the work of two students, all recent graduates in Psychology at Heriot-Watt. The blogs are presented as submitted by the students; they’ve not been edited. We hope you enjoy reading their work, and learning a bit more about the topics too! If you’re interested in using this approach in your own teaching, you can contact Alan Gow for more information and materials.

Starting the “brain blog” showcase, we have…

Can Certain Foods Really Improve Our Brain Function as we Age?

by Izzy Aitken

Consuming as much wine and cheese as you like sound great, right? Consuming as much wine and cheese as you like AND benefiting your mental abilities sounds even better. Recent research suggests that this might actually be the case with associations found between cognitive function and consumption of red wine, cheese and lamb.

Alzheimer’s disease (AD) is a progressive disease where individuals lose neurons in the hippocampus and cortex of the brain which leads to impairment in decision making, judgements, language and memory. Alzheimer’s disease accounts for approximately two thirds of dementia cases; dementia is an umbrella term and describes abnormalities in the brain which causes decline in cognitive abilities.

Our thinking abilities and problem-solving skills can be described as Fluid Intelligence; as such, declines in Fluid Intelligence have been found to increase the risk of AD in older age. For this reason, research by Klinedinst, Larsen, Pappas, Hoth, Pollpeter and Willette (2020) has explored how diet can influence fluid intelligence performance among older adults including those with/without family history of AD and those with/without a genetic risk to AD.

What does the research say?

The research paper had an analytical sample of 1,787 participants aged between 46 and 77 at the completion of the study. Control variables were accounted for including education, sex, body mass index, social- economic status and tobacco use. A longitudinal study was carried out whereby participants progress was followed over the course of 10 years; a fluid intelligence test (FIT) was administered at a baseline with two further assessments to follow up. Participants were also asked to report their food and drink consumption (food frequency questionnaire) at a baseline and with two further follow ups. These dietary predictors were then calculated into a mean for each participant for the total consumption for each type of food and drink.

Participants were categorised into four different groups dependent on their predisposition to AD: those with the genetic risk factor apolipoprotein E ε4 allele versus those without (APOE4+ vs APOE4-) and participants with a family history of AD versus those without (FH+ vs FH-). Statistically significant results were found among the FH-, APOE4- and APOE4+ groups finding consuming cheese daily predicted improved FIT scores; additionally, daily alcohol consumption could predict better FIT scores for the APOE4+ group with red wine having additional protective effects amongst FH+ and APOE4- groups. Weekly lamb consumption associated with improved FIT scores for FH- and APOE4+ groups. However, higher salt consumption in the at-risk groups (FH+ and APOE4+) appeared to correlate with decreased performance.

However, due to the observational nature of the study, direct causality cannot be inferred; just because there are significant associations between certain food and drink consumption and FIT scores doesn’t mean that these foods definitely cause improvements or declines in cognitive abilities.

How has this been reported in the media?

The Daily Mail boldly exclaims there is “No need to hold back on the cheese and wine this Christmas: Study shows they can REDUCE risk of Alzheimer’s and age-related cognitive decline”. From the title, there seems to be an over-emphasis of the research findings. Until further research can support the findings or prove causality, actively encouraging the public consume as much cheese and wine as desired appears far-fetched.

The article does accurately report findings from the study: the participants were reported as 1787 aged between 46 and 77 and data was collected through the UK Biobank. The article accurately details that FIT tests were administered 3 times over the course of 10 years; however, fluid intelligence is simply described as ability to ‘think on the fly’ which seems simplistic and leaves this definition open to questions. The article details that participants had to report their dietary intake though fails to mention that this was administered 3 times like the FIT tests which is important information as this reduces error variance in the results (fluctuation in scores).

General findings of the research are reported in the article with associations between cheese, daily consumption of alcohol (especially red wine) and weekly consumption of lamb improving long term cognitive abilities. Although, the article does not account for or even tell the reader how these findings these differed based on genetic risk factors to AD which could be misleading for readers as some groups had no association between consumption of these foods and cognitive ability e.g. the APOE4+ and FH- groups had no association between improved FIT scores and consuming red wine.

The article is accurate when reporting the findings of salt consumption as it details participants at a higher risk to AD and consumed high amounts of salt were found to have increased risk of cognitive problems. In addition, the article does clearly inform the reader of what Alzheimer’s disease with what happens and the symptoms.

What does it all mean?

The research found significant associations between cognitive function and consumption of red wine, cheese, lamb and salt which differed based on genetic and family history risk factors to Alzheimer’s Disease. Whilst it does sound ideal to consume as much cheese and wine as you like to improve your cognitive abilities (as the Daily Mail suggests), the research cannot confirm causality; in fact, there is research outlining the detrimental effects of excess consumption of alcohol and dairy to physical health so be careful: until there is additional supporting research, take these findings with a pinch of salt (but not too much!).

References

Klinedinst, B. S., Le, S. T., Larsen, B., Pappas, C., Hoth, N. J., Pollpeter, A., … & Willette, A. A. (2020). Genetic Factors of Alzheimer’s Disease Modulate How Diet is Associated with Long-Term Cognitive Trajectories: A UK Biobank Study. Journal of Alzheimer’s Disease, (Preprint), 1-13.

Randall, I. (2020, December 11). No need to hold back on the cheese and wine this Christmas: Study shows they can REDUCE risk of Alzheimer’s and age-related cognitive decline. The Daily Mail. Retrieved from https://www.dailymail.co.uk/sciencetech/article-9043033/Health-Cheese-wine-REDUCE-risk-Alzheimers-age-related-cognitive-decline-study-shows.html