Dementia, ultra-processed foods and the desire to disentangle the two

In the meat study, published online Wednesday in the journal Neurology, researchers from Harvard’s TH Chan School of Public Health and the Broad Institute of MIT and Harvard said they focused on red meat transformed in the hope that their results would inform new dietary guidelines expected later this year. year. Scientists advising federal health and agriculture agencies on the next edition of America’s influential Dietary Guidelines recently recommended an emphasis on alternative sources of protein, such as beans, peas and lentils, compared to red and processed meats.

For red meat lovers, the latest Harvard study brought some reassuring news; The study did not find a significant increase in dementia risk from eating “unprocessed” meat, such as ground beef or sirloin. But scientists found that eating about two servings per week of processed red meat correlated with a 13 percent higher risk of dementia than those who ate less than about three servings per month.

The study also concluded that replacing one serving of processed red meat, equal to 3 ounces, with one serving of nuts or legumes per day could reduce the risk of dementia by 19 percent, and by up to 28 percent. cent if the portion is replaced by fish.

“We want to bring all these healthier alternatives to the general public, because we don’t just want to say ‘please eat less red meat,'” said study lead author Dr. Daniel Wang , assistant professor at Harvard Medical School and Brigham and Women’s Hospital. “We want to send a positive message, not just limit people’s consumption.”

Researchers analyzed data from two long-term health studies involving more than 130,000 participants and followed them for up to 43 years, using regular food frequency questionnaires to assess the association between red meat and dementia.

Other researchers not involved in the study said the large number of participants and the length of time they were followed is the kind of evidence regulators need to consider when developing food policies. But they cautioned that the study, like many other dietary tracking studies, relies on participants’ memories of what they ate, which can sometimes be fuzzy.

In other new dementia findings, published in Nature Medicine, researchers analyzed data from another long-term study of more than 15,000 people in four states and found that about 40 percent of people older 55-year-olds would develop dementia during their lifetime.

“Our brain is a complex organ,” said Heather Snyder, senior vice president of medical and scientific relations for the Alzheimer’s Association, who was not involved in either dementia study. “What may contribute to a person’s risk (of dementia) is likely due to a number of factors, including the food we can eat and ensuring we have a balanced diet.”

The association is conducting its own research into the links between dementia, diet and lifestyle through a two-year study called US POINTER. Study, with more than 2,000 participants across five sites in the United States. The results are expected to be published in July.

Meanwhile, the association, drawing on a wealth of other research, believes that healthier foods – leaner vegetables, meats and proteins, as well as less processed and lower fat foods – can reduce the risk cognitive decline.

Public interest in “processed” and “ultra-processed” foods has increased since then-candidate Donald Trump announced he would nominate Robert F. Kennedy, Jr., an outspoken food critic transformed, to the position of Secretary of Health and Human Services. But researchers and regulators also have many questions about what exactly these terms mean and the impact of these foods on health.

Panel advises federal government on next edition of influential U.S. Dietary Guidelines did not distinguish between unprocessed and processed red meat in its recommendations and concluded that additional research was needed on the health impacts of so-called ultra-processed foods in general before further guidance could be provided in this category. This is expected to delay substantial changes to these processed foods until the next update in 2030.

Ultra-processed foods are an imprecise term that generally refers to foods with many added ingredients like sugar, oils, fats, and artificial colors or preservatives.

Many organizations refer to a classification system called NOVA that divides foods into four categories based on how much they are processed. Fresh or frozen vegetables, grains, beans, and other minimally processed foods are considered the healthiest, while those in the lower “ultra-processed” category, such as flavored yogurts, breakfast cereals, sugary juices , ice cream, cookies and more, are the most unhealthy. .

But Joanne Slavin, a professor of food science and nutrition at the University of Minnesota and a member of the 2010 American Dietary Guidelines advisory committee, said many seemingly healthy foods are often placed in an unhealthy category.

“Wholemeal breads are ultra-processed. Anything with four or more ingredients is ultra-processed,” Slavin said. “So pretty much everything gets put into that fourth category, which, you know, wasn’t intentional, but that’s kind of where it ends up.”

Susan Roberts, senior dean of research at Dartmouth College’s Geisel School of Medicine, who has also long studied nutrition, said there needs to be a closer look at the processed food classification system to better help the public understand how and what he should do. eat.

She said the recent advisory committee report on updating the U.S. dietary guidelines “did a good job of saying that ultra-processed foods, many of them, are likely to be bad, but evidence for this as a category is not there yet.”

Meanwhile, Slavin said she cautions consumers against information that puts all ultra-processed foods in the wrong basket.

“It’s like ‘never eat ultra-processed foods,’ when we haven’t even defined what an ultra-processed food actually is, and it makes us look bad in the health counseling field. when it comes to food and nutrition,” she said. “And I don’t blame consumers for saying, ‘Hey, why don’t you understand?’ »

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Kay Lazar can be reached at kay.lazar@globe.com Follow her @GlobeKayLazar.