Red meat has previously been linked to higher rates of cancer, identified as a contributor to climate change through production methods, and now a long-term study has linked it to an increased risk of dementia.
The findings come from researchers led by a team at the Harvard TH Chan School of Public Health in Boston and are based on records of 133,771 people in two US health databases. Participants were followed until age 43, with their eating habits assessed based on the likelihood of developing dementia.
Based on the 11,173 people in the study who developed dementia during the research period, consuming on average a quarter serving or more of processed red meats each day – about half a slice of bacon – means a 13% higher risk than those who only ate a small amount of red meat.
As cognitive assessments are included in health databases, researchers may also look into them. For every additional serving of processed red meat on average per day – one extra hot dog per day, approximately – accelerates cognitive aging by about 1.6 years.
“Higher consumption of red meat, particularly processed red meat, was associated with a higher risk of developing dementia and poorer cognition,” the researchers write in their published paper.
“Reducing red meat consumption could be included in dietary guidelines to promote cognitive health.”
It is important to recognize that studies of this type do not show direct cause and effect. All sorts of factors can play a role in dementia risk – from sleep quality to alcohol consumption to genetic variants – and this research hasn’t covered them all.
This means that eating more red meat cannot be said to be directly responsible for a higher risk of developing dementia. Since the study involved a very large group of people, it provides strong evidence of a connection between the two.
Unprocessed red meat – such as beef, lamb or pork that has not been preserved – has not been shown to be associated with dementia risk. However, there was a link between processed and unprocessed meat and self-reported subjective cognitive decline.
The team behind the study doesn’t stop there. The researchers want to take a closer look at why red meat might lead to dementia – including the changes meat makes to the gut microbiome – and also want to expand the analysis to a more diverse group of people.
“Dietary guidelines tend to focus on reducing the risks of chronic diseases like heart disease and diabetes, while cognitive health is less frequently discussed, although it is linked to these diseases,” explains the epidemiologist Daniel Wang, of the Harvard TH Chan School of Public Health.
“We hope our findings will encourage greater consideration of the link between diet and brain health.”
The research was published in Neurology.
