Many factors that contribute to cognitive decline are out of a person’s control, such as the genetics e i fsocioeconomic actors. But ongoing research increasingly indicates that poor diet is a risk factor for memory impairment during normal aging and increases the risk of develop Alzheimer’s disease.
But when assessing how certain diets may erode brain health as we age, research on the effects of eating minimally processed versus ultra-processed foods has been scant—that is, until now.
Two recent large-scale studies suggest that eating ultra-processed foods can exacerbate cognitive decline age-related and increase the risk of developing dementia. Conversely, another recent study reported that ultra-processed food consumption was not associated with an worse cognition in people over the age of 60.
Though more research is needed, such as neuroscientist who studies like the diet can affect cognition later in life, I find these early studies add a new layer to considering how critical nutrition is to brain health.
Many ingredients, minimal nutrition
Ultra-processed foods tend to be lower in nutrients and fiber and higher in sugar, fat and salt than unprocessed or minimally processed foods. Some examples of ultra-processed foods they include soda, packaged cookies, potato chips, frozen meals, flavored nuts, flavored yogurt, distilled alcoholic beverages, and fast food. Even packaged breads, including those high in nutritious whole grains, in many cases qualify as ultra-processed because of the additives and preservatives they contain.
Another way to look at it: You’re unlikely to find the ingredients that make up most of these foods in your home kitchen.
But don’t confuse ultra-processed with processed foods, which still retain most of their natural characteristics, even though they’ve undergone some form of processing — like canned vegetables, dried pasta, or frozen fruit.
Research analysis
In a December 2022 study, researchers compared the rate of cognitive decline over about eight years between groups of people who consumed different amounts of ultra-processed foods.
At the start of the study, more than 10,000 participants living in Brazil reported their eating habits for the previous 12 months. Then, for the next few years, the researchers assessed the participants’ cognitive performance with standard tests of memory and executive function.
Those who ate a diet containing the most ultra-processed foods at the start of the study showed slightly greater cognitive decline than those who ate little or no ultra-processed foods. This was a relatively small difference in the rate of cognitive decline between the experimental groups. It is not yet clear whether the small difference in cognitive decline associated with higher consumption of ultra-processed foods will have a significant effect at the level of an individual person.
The second study, with around 72,000 participants in the UK, measured the association between the consumption of ultra-processed foods and dementia. For the group that consumed the most ultra-processed foods, about 1 in 120 people were diagnosed with dementia over a 10-year period. For the group consuming little or no ultra-processed foods, this number was 1 in 170.
Research examining the relationship between health and ultra-processed foods uses the NOVA classification, which is a categorization system based on the type and extent of industrial food processing. Some nutritionists have criticized the NOVA classification for not having clear definitions of food processing, which could lead to misclassification. They also argue that potential health risks from consuming ultra-processed foods could be explained by low levels of fiber and nutrients and high levels of fat, sugar and salt in the diet rather than the amount of processing.
Many ultra-processed foods are high in additives, preservatives or colors, but they also have other hallmarks of an unhealthy diet, such as being low in fiber and nutrients. Thus, it is unclear whether consuming foods that have undergone increased processing has an additional negative impact on health beyond the scarsa quality of diet.
For example, you might eat a hamburger and fries from a fast food chain, which would be high in fat, sugar and salt as well as being ultra-processed. You could make the same meal at home, which might be high in fat, sugar and salt but wouldn’t be ultra-processed. More research is needed to determine if one is worse than the other.
Brain healthy diets
Even when the processes leading to dementia do not occur, the aging brain undergoes biochemical and structural changes that are associated with impaired cognition.
For adults over the age of 55, a healthier diet could increase the likelihood of maintaining better brain function. In particular, the Mediterranean diet and the ketogenic diet are associated with improved cognition in later life.
The Mediterranean diet emphasizes eating plant-based foods and healthy fats, such as olive oil, seeds and nuts. The ketogenic diet is high in fat and low in carbohydrates, with the primary source of fiber coming from vegetables. Both diets minimize or eliminate sugar consumption.
Our research and the work of others show that both diets can reverse some of these changes e improve cognitive functionpossibly reducing harmful inflammation.
While inflammation is a normal immune response to injury or infection, it is a chronic one could be harmful to the brain. Studies have shown that excess sugar and fat may contribute to chronic inflammation is that ultra-processed foods might also exacerbate harmful inflammation.
Another way diet and ultra-processed foods can affect brain health it is through the gut-brain axis, which is the communication that takes place between the brain and the gut microbiomeor the community of microorganisms that live in the digestive tract.
The gut microbiome not only aids digestion, but also influences the immune system, producing hormones and neurotransmitters essential for brain function.
Studies have shown that diets ketogenic e Mediterranean they change the composition of microorganisms in the gut in ways that benefit the person. The consumption of ultra-processed foods is also associated with alterations of type and abundance of intestinal microorganisms that have more harmful effects.
The uncertainties
Untangling the specific effects of individual foods on the human body is difficult, in part because keeping close tabs on people’s diets to study them over long periods of time is problematic. Also, studies randomized controlled trialsthe most reliable type of study for establishing causation, are expensive to realize.
So far, most nutritional studies, including these two, have only shown correlations between consuming ultra-processed foods and health. But they can’t rule it out other lifestyle factors such as exercise, education, socioeconomic status, social connections, stress, and many other variables that can affect cognitive function.
This is where lab studies using animals are incredibly useful. Rats show cognitive decline in old age which is parallel to humans. It’s easy to monitor rodent diets and activity levels in a laboratory. And rats go from middle age to old age in just a few months, which shortens study times.
Laboratory studies on animals will help determine whether ultra-processed foods play a key role in the development of cognitive impairment and dementia in people. As the world population ages and the increasing number of older adults with dementiathis knowledge cannot come soon enough.
(Sara N. Burke – Associate Professor of Neurobiology and Cognitive Aging, University of Florida – su The Conversation del 31(/01/2023)
the association does not receives and is against public funding (also 5 per thousand)
Its economic strength are inscriptions and contributions donated by those who deem it useful
DONATE NOW