Scientists from the University’s Nutritional Epidemiology Group used data from 500,000 people to find that eating 25 grams of processed meat per day, the equivalent of one serving of bacon, was associated with a 44% increased risk of developing the disease.
But their study found that eating some unprocessed red meat, such as beef, pork or beef, may be protective, as those who ate 50 grams per day were 19% less likely to develop dementia.
The researchers were exploring whether there was a link between meat consumption and the development of dementia, a health condition that affects 5%-8% of those in their 60s worldwide.
Their findings, titled Meat consumption and risk of incident dementia: study involving 493,888 UK Biobank participants, are published today. American Journal of Clinical Nutrition.
Lead researcher Huifeng Zhang, a PhD student at the Leeds School of Food Science and Nutrition, said: “Globally, the prevalence of dementia is increasing and diet may play a role as a modifiable factor.
“Our study adds to the growing body of evidence that shows processed meat consumption increases the risk of various non-communicable diseases.”
The research was supervised by Professors Janet Cade and Laura Hardy from Leeds.
The team studied data provided by the UK Biobank, a database containing in-depth genetic and health information from half a million UK participants aged 40 to 69, to investigate the relationship between different types of meat consumption and risk of dementia.
Data collected by UK Biobank in 2006-2010 included six options for how often participants ate different types of meat, once or more per day. The study did not specifically assess the effect of vegetarian or vegan diets on dementia risk, but did include data from people who said they were red. don’t eat meat
Among the participants, 2,896 cases of dementia emerged over an average of eight years of follow-up. These people are generally older, more economically deprived, less educated, more likely to smoke, less physically active, more likely to have a history of stroke and family dementia, and more likely to be carriers of a gene highly associated with dementia. More men than women were diagnosed with dementia in the study population.
Some people were three to six times more likely to develop dementia due to well-established genetic factors, but the results indicated that the risk of eating processed meat was the same whether or not a person was genetically predisposed to developing the disease.
Those who ate more processed meat were more likely to be male, less educated, smokers, overweight or obese, eat less vegetables and fruit, and eat more energy, protein and fat (including saturated fat).
Meat consumption has previously been linked to dementia risk, but this is believed to be the first large-scale study of participants over time to examine a link between the type and amount of specific meat and the risk of developing the disease.
There are approximately 50 million dementia cases worldwide, with approximately 10 million new cases diagnosed each year. Alzheimer’s disease accounts for 50% to 70% of cases and vascular dementia in about 25%. Its development and progression are linked to both genetic and environmental factors, including diet and lifestyle.
Ms Zhang said: “Further confirmation is needed, but the direction of the effect is linked to current healthy eating guidelines which recommend that eating less unprocessed red meat may have health benefits.”
Professor Cade said: “Anything we can do to explore potential risk factors for dementia can help us reduce rates of this debilitating condition. This analysis is a first step in understanding whether what we eat can affect risk.”