Adding bacon to your morning breakfast could increase your risk of dementia, experts warn.
In a recently presented study, described as one of the most “robust” to date, researchers followed more than 100,000 adults over four decades to assess the link between diet and cognitive health.
The team, from Brigham and Women’s Hospital in Boston, found that adults who ate at least two servings per week of processed red meat were 14 percent more likely to develop dementia compared with those who ate fewer than three servings per month.
But replacing that slice of bacon with a serving of nuts or beans was enough to reduce the risk of cognitive decline by 20 percent.
Processed meats like bacon were linked to a 14 percent increased risk of dementia, according to newly presented research.
The chart above shows Alzheimer’s rates per 100,000 people, both age-standardized and for all ages. Age-standardized is a method used to adjust for differences in age distribution between populations or over time, while non-age-standardized is the crude rate calculated for all age groups in the population without any adjustment.
The findings come at a time when processed meats such as bacon and hot dogs have been blamed for a host of health problems, including a rise in colorectal cancer among young Americans.
Dr Maria Carrillo, chief scientific officer at the Alzheimer’s Association, said: “This is one of the most robust studies I’ve seen linking processed meat consumption to dementia, because they actually followed individuals for decades.”
The study, which has not yet been published, followed 130,000 adults for 43 years. Every two to four years, the team collected nutritional data on each participant.
They were asked how often they ate a serving of processed red meat, which could include two slices of bacon, a hot dog, two small sausages and sandwiches made with salami, bologna or other processed meats. In addition, the researchers asked them how often they ate nuts or legumes.
The team then compared the cognitive health of those who ate at least two servings of processed meat per day with those who consumed fewer than three servings per month.
In addition to the 14 percent increase in dementia risk, each additional serving of processed meat per day added 1.6 extra years of cognitive aging, specifically in the areas of the brain that control language and behavior.
However, unprocessed red meats, such as ground beef and steak, do not carry the same risks. “When unprocessed and consumed in moderation, red meat is acceptable,” said Dr. Carrillo.
He said this could be because processed meats contain nitrates, chemical compounds used to keep meat fresh and preserve color.
When consumed, nitrates are converted into nitrosamines, which can damage cells and neurons, impairing cognitive health.
Nitrosamines also promote inflammation in the brain, which breaks down crucial neurotransmitters and produces plaques that degrade brain health.
Bacon and cold cuts also have high levels of saturated fat and cholesterol, which have been shown to cause atherosclerosis, a buildup of fat in the arteries that restricts blood flow to the brain and contributes to cognitive decline.
Additionally, the high sodium content in processed meats may lead to high blood pressure, which over time can damage blood vessels in the brain.
Bacon is considered an ultra-processed food, typically going through at least five levels of processing, including curing, smoking and slicing.
Other recent research has observed similar effects. A 2021 study published in American Journal of Clinical Nutrition A study of nearly 500,000 adults, for example, found that eating 25 grams of processed meat per day (about six slices of bacon) increased the risk of dementia by 44 percent.
That intake was also associated with a 52 percent increased risk of Alzheimer’s disease, the most common form of dementia.
The new findings also suggest that replacing one of those servings of processed meat with a serving of nuts or beans could reduce the risk of dementia by 20 percent.
“Those are anti-inflammatory foods, so you can imagine they have a lot of benefits beyond cutting out processed meats with toxins, nitrates and sodium that are not good for you,” Dr. Carrillo said.
The research had some limitations. The participants were mostly white and of high socioeconomic status, meaning the results might not represent the majority of the U.S. population.
The study was also observational, so it can only show associations rather than direct causes.
The research was presented Wednesday at the Alzheimer’s Association International Conference in Philadelphia.