The risk for dementia dropped by 20%, however, for people who replaced that small daily serving of processed red meat with a daily serving of nuts and legumes.
Processed red meats such as bacon, sausage, hot dogs and deli meats often contain higher levels of sodium, nitrates and saturated fat. Eating higher amounts of these meats has been strongly linked to the development of colon and other cancers, type 2 diabetes, and heart disease and stroke, studies have shown.
“There is much we can do to reduce the risks of dementia, starting with actions that are well known to reduce risks of cardiovascular disease,” said Dr. Walter Willett, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health in Boston.
“There are still aspects of this to understand in more detail,” Willett said in an email. “For example it seems that some foods may be particularly important to include and we would like to understand the specific active ingredients, but we don’t need to wait for all the details to take action.”
The study was observational and can only show an association and not necessarily cause and effect, said Dr. David Katz, a specialist in preventive and lifestyle medicine who was not involved in the study.
“However, the associations are very likely to be causal, because the principal risk factors for Alzheimer’s and cognitive decline are the risk factors for cardiovascular disease, with which processed meat intake is strongly linked,” he said in an email. Katz is the founder of the nonprofit True Health Initiative, a global coalition of experts dedicated to evidence-based lifestyle medicine.
Each additional serving of processed red meat raised risk
An abstract of the study, which is under review for publication, was presented Wednesday at the 2024 Alzheimer’s Association International Conference in Philadelphia.
Every two to four years for over three decades, researchers captured dietary data from more than 130,000 participants in the Nurses’ Health Study, one of the largest investigations into the risk factors for major chronic diseases in women, and the complimentary Health Professionals Follow-Up Study, which investigated the same risk factors in men.
The men and women were asked how often they ate a serving of processed red meat, which could be two slices of bacon, one hot dog, two small links of sausage or kielbasa, and salami, bologna or other processed meat sandwiches.
The study participants were also asked how often they ate nuts and legumes, such as 1 tablespoon of peanut butter; 1 ounce of peanuts, walnuts or other nuts; an 8-ounce glass of soy milk; a half cup of string beans, lentils, beans, peas or lima beans; or a typical 3-ounce serving of tofu or soy protein.
“Those are anti-inflammatory foods, so you can imagine they have a lot of benefits in addition to reducing the processed meats with toxins, nitrates and sodium which are not good for you,” said Dr. Maria Carrillo, chief science officer of the Alzheimer’s Association, who was not involved in the study.
