A new study says that consuming 25 grams of processed meat a day is associated with a 44 per cent increased risk of developing dementia.
It adds that consuming 50g of unprocessed meat, such as beef or pork, each day might be protective against the disease.
The findings from the University of Leeds School and Food Science and Nutrition were based on an observational study of nearly 500,000 UK participants aged 40 to 69.
Lead researcher Huifeng Zhang said: “Worldwide, the prevalence of dementia is increasing and diet as a modifiable factor could play a role. Our research adds to the growing body of evidence linking processed meat consumption to increased risk of a range of non-transmissible diseases.”
Ms Zhang said more confirmation of the links was needed but suggested “lower intakes of unprocessed red meat could be beneficial for health”.
Study supervisor Professor Janet Cade said her group’s work was a “first step” towards understanding dietary links to risk factors for dementia.
“Anything we can do to explore potential risk factors for dementia may help us to reduce rates of this debilitating condition.”
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Other experts have warned that the study does not prove causal links between meat and dementia, a set of disorders that affect the brains of 5 to 8 per cent of people aged over 60 worldwide.
Kevin McConway, emeritus professor of applied statistics at the Open University, said the study was inconclusive.
“The study can’t show that processed meat actually causes an increase in dementia risk, any more than it can show that eating non-processed red meat can cause dementia risk to decrease. The findings are interesting, but they don’t establish anything for certain.”
Professor Paul Matthews, director of the UK Dementia Research Institute at Imperial College London, said: “It is premature to propose changing dietary recommendations on the basis of associations like these alone.”
Robert Howard, professor of old age psychiatry at University College London, said: “As a doctor who works clinically with people with dementia and conducts research into potential dementia treatments, the data wouldn’t persuade me to give up my breakfast bacon.”
A 25g serving of processed meat is equivalent to one rasher of bacon.
The study found that those who ate more processed meat were more likely to be male, less educated, smokers, overweight or obese, had lower intakes of vegetables and fruits, and had higher intakes of energy, protein, and fat (including saturated fat).
The potential risks from eating processed meat were the same whether or not a person was genetically predisposed to developing the disease.
Meanwhile, a study published in the Journal of the American Heart Association contends that post-menopausal women who consume protein from plant-based sources such as beans and nuts instead of red meat are less likely to die prematurely from dementia and heart disease.
Lead study author Dr Wei Bao, an assistant professor of epidemiology at the University of Iowa, said future diet guidelines needed to consider what proteins were healthiest.
“Current dietary guidelines mainly focus on the total amount of protein, and our findings show that there may be different health influences associated with different types of protein foods.”
Researchers analysed the diets of more than 100,000 women aged 50 to 79 from the national Women’s Health Initiative study. The women were followed for up to 25 years to see how what they ate affected their long-term health.
The Telegraph reports that women who ate the most plant protein had a 21 per cent lower risk of dying from dementia, a 12 per cent lower risk of dying from heart disease and a 9 per cent lower risk of death from all causes compared to those who ate the least plant protein.
“Those who ate the most processed red meat had a 20 per cent higher risk of dying from dementia compared to those who ate the least. Eating unprocessed red meat and dairy also raised the risk of dying from cardiovascular disease: Those who ate the most meat were 12 per cent more likely to die and those who ate the most dairy were 11 per cent more likely.”
Researchers said the findings had to be taken into consideration with other factors, such as what other foods proteins are served with and how they are prepared.
Australia’s Cancer Council accepts the World Health Organization classification of processed meats including ham, bacon, salami and frankfurts as group one carcinogens. This means there’s strong evidence that processed meats cause cancer. Red meat, such as beef, lamb and pork, has been classified as a group 2A carcinogen, which means it probably causes cancer.
The council recommends eating no more than one serve of lean red meat per day or two serves three to four times per week.
Have you reduced your consumption of processed meats or red meat? Do you know the best substitutes for red meats?
Read more: How to reduce your risk of dementia
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