Rising processed food consumption may put memory at risk, flags researchers

18 Oct 2021 --- Ultra-processed food (UPF) consumption is on the rise, particularly among the 60-plus demographic, according to a new study. This is especially concerning in light of separate research that found a link between processed food consumption and memory loss in older populations.

“Given the accumulating evidence linking UPF to poor diet quality and obesity, there is a need to increase public awareness around the harms of UPF and to develop policies and public health interventions to reduce their consumption,” Filippa Juul, the study’s lead author at  New York University School of Public Health, NutritionInsight. 

Her research measuring the consumption of food by type, spanning from 2001 to 2018, found an increase in the intake of UPF in the US population, regardless of income.

Published in the American Journal of Clinical Nutrition, it analyzed dietary data from almost 41,000 adults who took part in the National Health and Nutrition Examination Survey by the Centers for Disease Control and Prevention.

People aged 60 and above have the largest increase in UPF consumption over the past 18 years.

Driving the obesity epidemic?
According to Juul, the intake of UPF was already high in 2001 when the study began but “increased continuously over the study period.”

While many consumers are confused about UPFs, the study defines them as industrially manufactured, ready-to-eat or heat foods that include additives. These items are devoid of whole foods – or minimally processed foods – such as vegetables, fruits, grains, meat and dairy. 

While consumption of ready-to-eat or heat meals, like frozen dinners, increased the most, the intake of some sugary foods and drinks declined, the study notes. Overall, UPF consumption grew from 53.5% of calories in the beginning of the period studied (2001-2002) to 57% at the end (2017-2018).

The UPF intake increased across all demographic groups, except for Hispanic groups, while whole foods decreased from 32.7% to 27.4% of calories across all US consumers, mostly due to people eating less meat and dairy.

“The high and increasing consumption of ultra-processed foods in the 21st century may be a key driver of the obesity epidemic,” Juul notes.

Elderly bear the brunt
The sharpest increase of UPF consumption is observed in older adults aged 60 and above. Most notably, the group had the least consumption of UPF in the beginning of the study period and the highest intake of whole foods. By the end of the study period, the patterns were reversed, and this was the group consuming the most UPF and the least amount of whole foods. 

These findings could also be concerning when linked to an Ohio State University (OSU) rat study, which found that older participants consuming UPF had behavioral signs of memory loss. 

Though the research was carried out on rats as opposed to humans, Ruth Barrientos, lead author of the paper and associate professor of psychiatry and behavioral health at OSU, tells NutritionInsight that the study could be applicable to humans. 

“Given evidence that, on average, over 40% of calories consumed in the US come from low-quality carbohydrates, this is very relevant to humans. Human studies not done by us have shown aging-related reductions in DHA levels, and this has been correlated with reduced cognitive function,” Barrientos notes. 

Omega 3 was found to reduce memory problems in older rats that consumed processed food.

DHA’s preventative effects
The study observed an inflammatory response in the brains of older rats compared to young rats during the four-week research, whose findings were published in Brain, Behavior, and Immunity. 

Where the processed food diet was supplemented with omega 3 fatty acid DHA, the study noted it appeared to prevent memory problems and reduce the inflammatory effects almost entirely in older rats. 

This, however, should not be taken to mean that people should enjoy diets with processed foods as long as they take omega 3 supplements, Barrientos notes. 

“These findings indicate that consumption of a processed diet can produce significant and abrupt memory deficits – and in the aging population, rapid memory decline has a greater likelihood of progressing into neurodegenerative diseases such as Alzheimer’s disease. 

“By being aware of this, we can limit processed foods in our diets and increase consumption of foods that are rich in the omega 3 fatty acid DHA to either prevent or slow that progression,” she says. 

This is not the first study to caution against using supplements to reduce inflammation and instead, with previous researchers focusing on consumer education and product transparency.

Nonetheless, key suppliers in the industry have previously told NutritionInsight that while omega 3 supplements are widely taken, consumers still lack sufficient knowledge to get the right dose and form for optimal health. 

By Andria Kades