- According to an observational study, consuming 25 grams (g) of processed meat per day — roughly one rasher of bacon — is linked to a 44 percent increased risk of dementia.
- The study also found an association between eating unprocessed red meats, such as beef, pork, and veal, and reduced risks of all-cause dementia.
- The APOE 4 allele, which increases a person’s risk of dementia by 3–6 times, did not appear to have any effect on the link between diet and dementia.
In 2014, about 5 million people in the United States had dementia, according to the Centers for Disease Control and Prevention (CDC)Trusted Source. However, the CDC predicts that by 2060, this figure will be close to 14 million.
According to the World Health Organization (WHO), there are approximately 50 million dementia cases worldwide, with approximately 10 million new cases diagnosed each year.
Alzheimer’s disease, which accounts for 60–70% of dementia cases, is the most common cause.
The development and progression of dementia are believed to be influenced by genetic and environmental factors, including diet and lifestyle.
People’s average meat intake has been linked to their risk of contracting the disease in previous studies.
However, a recent study from researchers at the University of Leeds in the United Kingdom indicates that consuming processed meat, in particular, is linked to an increased risk of dementia.
Sausages, bacon, salami, and corned beef are examples of processed meats.
Red meat, on the other hand, seems to have a protective effect against dementia, according to the study.
The American Journal of Clinical Nutrition published the study.
Diet, genetics, and lifestyle
The researchers looked at data from the UK Biobank, which is a collection of genetic and health information from about half a million UK volunteers aged 40 to 69.
Every participant completed a dietary questionnaire and 24-hour dietary tests when they were recruited for the project.
The researchers were able to estimate the overall amount of meat each participant consumed on a regular basis, as well as how much of each form of meat they consumed.
They were also able to determine which participants had the gene variant APOE 4 allele, which has been linked to an increased risk of dementia.
During the 8-year follow-up period, they used hospital and death data to distinguish subsequent cases of dementia from all causes, Alzheimer’s disease, and vascular dementia.
There were 2,896 people with all-cause dementia among the 493,888 people who took part in the survey. There were 1,006 cases of Alzheimer’s and 490 cases of vascular dementia among them.
The researchers had to account for a wide variety of other variables that are known to influence a person’s risk of developing dementia in order to estimate the function of meat consumption.
Age, gender, ethnicity, education, and socioeconomic status were among them. In addition, lifestyle factors such as smoking, physical activity, and consumption of fruits and vegetables, fish, tea, coffee, and alcohol were taken into account.
After making these changes, they discovered that every additional 25 g of processed meat consumed per day was linked to a 44% increase in the risk of dementia from every cause.
This consumption was also linked to a 52 percent higher risk of Alzheimer’s disease.
Each additional 50-g portion of unprocessed meat consumed per day, on the other hand, was linked to a 19% reduction in the risk of all-cause dementia and a 30% reduction in the risk of Alzheimer’s disease.
The intake of unprocessed poultry and total meat was not statistically important.
A higher risk of vascular dementia was linked to eating a lot of processed meat, but the correlation with steady increasing daily intake was not important.
The researchers found that having the APOE 4 allele increased the risk of dementia by 3–6 times, as predicted. It did not, however, have a substantial impact on the reported links between diet and dementia.
Processed meat and disease risk
Processed meat consumption has been linked to cancer by a wide body of evidence. The World Health Organization (WHO) also listed it as a carcinogen in 2015.
“The incidence of dementia is growing worldwide, and diet as a modifiable factor could play a role,” says Huifeng Zhang, a Ph.D. student at the University of Leeds’ School of Food Science and Nutrition and the study’s lead researcher.
“Our findings contribute to the increasing body of evidence linking processed meat consumption to an increased risk of non-communicable diseases,” she says.
It’s worth remembering that the researchers expressed their findings as a percentage increase in the likelihood of dementia, or “relative risk.”
This is in contrast to the change in “absolute risk,” or the number of additional cases per 1,000 people, for example.
Data from the UK Biobank, according to Ms. Zhang, are unsuitable for measuring absolute risk since it is not a representative sample of the entire population.
She argues, for example, that it does not have a high enough proportion of people over the age of 70.
Since the probability of dementia increases with age, any measurement of absolute risk will be distorted by this imbalance.
It’s also worth remembering that while this was an observational study, it couldn’t conclusively show that processed meat causes dementia. It does, however, show that there is a statistical correlation between the two.
Prof. Robert Howard, professor of old age psychiatry at University College London in the United Kingdom, who was not involved in the research, says, “It’s always necessary to note when looking at studies like this that they can’t assign causation and [that] important confounding factors might account for apparent associations.”
“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,” he adds.