Foods That Are Highly Processed May Cause Cognitive Decline

Summary: Ultra-processed foods have been connected with faster aging-related cognitive loss and a higher risk of dementia. A better diet, like the keto or Mediterranean diet, may be able to reduce some of the harmful effects of food on cognition, according to researchers.

Since many years ago, scientists have been aware that poor diets, especially those high in fat and sugar, can harm the brain and impair cognitive function.

A person has little control over many factors that affect cognitive decline, such as genetics and socioeconomic factors. However, more and more evidence is pointing to a poor diet as a risk factor for memory loss as people age normally and as a contributor to the development of Alzheimer’s disease.

However, until recently, there hasn’t been much research comparing the impacts of eating minimally processed versus highly processed meals when assessing how some diets may deteriorate brain function as we age.

Eating foods that have undergone extreme processing may aggravate age-related cognitive decline and raise the risk of acquiring dementia Another recent study, however, found no link between eating foods that have undergone extreme processing and cognitive decline in adults over the age of 60.

As a neuroscientist who studies how diet can affect cognition later in life, I find that these preliminary studies give a new dimension for thinking about how essential nutrition is to brain function, even though more research is required.

Lots of ingredients, minimal nutrition

Compared to unprocessed or minimally processed foods, ultra-processed foods typically have lower nutritional and fiber contents and greater levels of sugar, fat, and salt. Soda, packaged cookies, chips, frozen dinners, flavored almonds, flavored yogurt, distilled alcoholic beverages, and fast food are a few examples of ultra-processed foods. Because of the additives and preservatives they include, even packaged breads, particularly those rich in nutritive whole grains, qualify as ultra-processed in many situations.

Another way to look at it is that you probably won’t find the components of the majority of these delicacies in your kitchen.

Contrast ultra-processed foods with processed foods, which have undergone some type of processing but still maintain the majority of their natural qualities, such as canned vegetables, dried pasta, or frozen fruit.

Parsing the research

Researchers assessed the incidence of cognitive impairment over a period of eight years across groups of persons who consumed various amounts of ultra-processed foods in a study published in December 2022.

More than 10,000 Brazilian participants who were living at the time of the study provided information on their eating routines over the previous 12 months. The subjects’ cognitive abilities were then assessed over the next years using common memory and executive function tests.

At the beginning of the trial, those who consumed more ultra-processed meals had a modest increase in cognitive deterioration compared to those who consumed little to no ultra-processed foods. The difference in the rate of cognitive deterioration between the experimental groups was rather small. It is not yet known if the slight variation in At the level of the individual person, the cognitive deterioration linked to increased consumption of ultra-processed foods will have a significant impact.

The second study examined the relationship between eating highly processed foods and dementia and included roughly 72,000 participants in the United Kingdom. Over a ten-year period, 1 in 120 members of the group that consumed the most ultra-processed meals had dementia diagnoses. This number was 1 out of 170 for the group that ate little to no ultra-processed foods.

The NOVA classification, a system of categorizing based on the type and intensity of industrial food processing, is used in research to examine the association between health and ultra-processed foods. The NOVA classification has drawn criticism from several nutritionists for its unclear definitions of food processing, which could result in categorization errors. Additionally, they contend that rather than the degree of processing, the possible health concerns associated with consuming ultra-processed foods may be explained by the diet’s high quantities of fat, sugar, and salt and low levels of fiber and minerals.

In addition to having a lot of chemicals, preservatives, or coloring agents, ultra-processed foods frequently lack fiber and other essential nutrients and have other characteristics of an unhealthy diet. Therefore, it is unsure if consuming food that has gone beyond a poor diet, and greater processing has a detrimental effect on health.

You could, for instance, have a burger and fries from a fast food restaurant, which would be extremely processed and rich in fat, sugar, and salt. That same meal may be prepared at home, where it wouldn’t be as processed but might still be rich in fat, sugar, and salt. To ascertain whether one is worse than the other, more research is required.

Brain-healthy diets

The aging brain goes through biochemical and structural changes that are linked to worsening cognition even when the factors that cause dementia are not present.

However, a healthier diet may boost the likelihood of preserving superior brain function in persons over the age of 55. The Mediterranean diet and the ketogenic diet, in particular, are linked to greater cognition in old age.

Consuming plant-based foods and healthy fats like olive oil, seeds, and nuts is prioritized in the Mediterranean diet. The main source of fiber on the ketogenic diet, which is primarily derived from veggies, is vegetables. Both diets reduce or completely forbid sugar consumption.

Both diets can improve cognitive performance and reverse some of these abnormalities, according to our research and that of others. This may be because they both lower detrimental inflammation.

Chronic inflammation can be harmful to the brain even if it is a typical immunological response to injury or infection. Excess sugar and fat, as well as highly processed diets, have both been linked in studies to the development of chronic inflammation.

The gut-brain axis, which is the communication that takes place between the brain and the gut microbiome, or the community of bacteria that dwell in the digestive tract, is another way that diet and ultra-processed foods may affect brain health.

The gut microbiome not only aids in digesting but also regulates the immune system and secretes hormones and neurotransmitters that are critical for brain function.

According to studies, the ketogenic and Mediterranean diets alter the gut’s microbial population in ways that are advantageous to the individual. Consumption of ultra-processed foods is also linked to changes in the variety and number of gut microbes that have more detrimental consequences.

The uncertainties

It is challenging to separate the precise effects of various foods on the human body, in part because it is challenging to maintain perfect control over subjects’ diets for extended periods of time. Randomized controlled trials, the most trustworthy sort of research for proving causation, but very expensive to conduct.

Most nutritional studies to date, including these two, have only demonstrated links between consuming highly processed foods and health. However, they cannot rule out other lifestyle elements that may affect cognitive performance, such as exercise, education, socioeconomic status, social relationships, stress, and a host of other things.

Studies conducted in laboratories using animals are highly beneficial in this regard. Rats exhibit similar aging cognitive impairment to humans. In a lab, it’s simple to regulate the meals and activity levels of rodents. Additionally, rats reach old age in a matter of months, cutting down on study duration.

It will be feasible to evaluate whether ultra-processed meals are significantly contributing to the emergence of cognitive deficits and dementia in humans through lab-based investigations in animals. As the population of the planet ages and the number of older adults with dementia increases, this knowledge cannot come soon enough.

Credits:

Author: Sara N. Burke

Source: The Conversation

Contact: Sara N. Burke — The Conversation