How genetics, diet and gut health influence Alzheimer’s risk

Scientists at the University of East Anglia and the Quadram Institute are launching a new study to investigate how our genes, diet and microbiome influence the risk of dementia.

Recent research has linked gut health to Alzheimer’s disease. And dietary compounds found in foods including fruits and vegetables, tea and dark chocolate, have been found to reduce Alzheimer’s risk.

Now, the team want to better understand how these compounds, called polyphenols, influence the microbiome and Alzheimer’s risk. They will also look at the role that genetics play.

And they are looking for more than 150 people to take part in the study.

Dr David Vauzour, from UEA’s Norwich Medical School, said: “What causes age-related cognitive conditions like Alzheimer’s isn’t fully understood.

“Age is a major risk factor - but genetics also plays a role, with specific versions of a gene called APOE implicated. Diet is also a significant risk factor, and it’s likely that diet and genetics interact during disease onset.

“Recent research has linked the population of gut microbes, known as our microbiome, to Alzheimer’s disease, as people with the condition tend to have a different make up of bacterial species.

"The composition of our microbiome influences not just our gut health, but also the health of our whole bodies, including our brains. This is because the microbes break down dietary compounds and release them into the blood.

“We want to better understand this whole process.”

The team will study how polyphenols - found in berries, cocoa, apples and tea - influence the microbiome, and investigate links to Alzheimer’s risk.

Participants will be asked to provide a saliva sample to determine what type of the APOE gene they carry and then faecal samples to create a sophisticated model of the gut.

This will then be used to understand how their microbes break down polyphenols, how diet influences the composition of the microbiome and how the products made when the microbes breakdown polyphenols may influence the risk of developing Alzheimer’s.

The researchers will run this microbiome model using samples from people with different versions of the APOE gene.

They hope that their work will answer questions about how the APOE gene and dietary polyphenols affect the microbiome and influence the risk of developing age-related cognitive conditions like Alzheimer’s, and even suggest ways of mitigating that risk as we get older.

The study is recruiting people aged 18-35, and also over 55 years old. A number of men and women in each age group, with different versions of the gene, will then be asked to provide a faecal sample.

This will allow the researchers to culture a version of each person’s microbiome in the laboratory. People can participate in the study in hybrid, either coming in person or remotely from their own homes.

To find out more visit https://quadram.ac.uk/diamond-study/ or email DIAMOND.study@uea.ac.uk