Latest studies examine diet’s impact on cognitive abilities and cardiovascular disease

When it comes to medical journals and research studies, there are almost an endless supply of resources available. This can make it difficult for physicians to stay abreast of the most up-to-date and relevant pieces that are applicable to the work they do.

Since staying current with the latest medical research is an important part of a career in medicine, we have searched through the latest information to find three new studies that many DOs will find significant. See below for summaries and links to the original research.

“Association Between Consumption of Ultraprocessed Foods and Cognitive Decline,” JAMA Network, Dec. 5, 2022

Research has shown that the consumption of ultraprocessed foods is linked to a higher risk of cardiovascular disease, metabolic syndrome and obesity. However, not much is known about how the consumption of ultraprocessed foods correlates to cognitive decline. This study set out with the objective to examine the link between the consumption of ultraprocessed foods and cognitive decline.

To investigate this, researchers developed a multicenter, prospective cohort study with three waves, approximately four years apart, between 2008 and 2017. The data was analyzed from December 2021 to May 2022. The participants were public servants ranging in age from 35 to 74 years old and were recruited in six different Brazilian cities. Participants who did not complete the food frequency questionnaire were excluded, along with those who reported extreme caloric intake (over 6,000 calories per day). Additionally, individuals who reported taking medication that could negatively impact their cognitive performance were also excluded.

Over time, changes in cognitive performance were evaluated using immediate and delayed word recall, word recognition, phonemic and semantic verbal fluency tests and Trail-Making Test B version. Overall, 10,775 participants’ data was analyzed. The mean age at the baseline was 51.6 years. Of those studied, 5,880 (54.6%) participants were women; 5,723 (53.1%) were white; and 6,106 (56.6%) had at least a college degree. During eight-year follow-ups, individuals with ultraprocessed food consumption above the first quartile displayed a 28% faster rate of global cognitive decline as well as a 25% faster rate of executive function decline compared to those in the first quartile.

This study was able to conclude that a higher rate of the consumption of ultraprocessed foods was associated with cognitive decline among adults. Additionally, the findings supported current public health recommendations on limiting the consumption of ultraprocessed foods due to their potential harm to cognitive function.

“Adding Salt to Foods and Risk of Cardiovascular Disease,” JACC Journals, Dec. 2022

Researchers conducting this study recently found that the frequency of adding salt to foods could impact a person’s long-term salt taste preference and sodium intake. Additionally, they found that it was significantly related to an individual’s life expectancy. In this study, researchers set out to determine whether the frequency of adding salt to foods was associated with incident cardiovascular disease risk.

This study included nearly 180,000 adults who were initially free of CVD. Cox proportional hazards models were utilized to estimate the correlation between the frequency of adding salt to foods and cardiovascular disease events.

With a median of 11.8 years of follow-up, there were 9,963 total cardiovascular disease events, 6,993 ischemic heart disease cases, 2,007 stroke cases and 2,269 heart failure cases. A lower frequency of adding salt to foods was significantly associated with a lower risk of cardiovascular disease events, which was determined after adjusting for covariates and the Dietary Approaches to Stop Hypertension (DASH) diet.

Compared with the group that always added salt to foods, the adjusted hazard ratios were 0.81 (95% CI: 0.73-0.90), 0.79 (95% CI: 0.71-0.87), and 0.77 (95% CI: 0.70-0.84) across the groups of usually, sometimes, and never/rarely, respectively (P trend < 0.001). Among the subtypes of cardiovascular disease, adding salt had the greatest association with heart failure but was not associated with stroke. Researchers found that participants who utilized the DASH diet and had the lowest frequency of adding salt to foods had the lowest cardiovascular disease risk. It was concluded that adding salt to foods on a lower frequency is associated with a lower risk of cardiovascular disease, especially heart failure and IHD.

“Association of Dietary Intake of Flavonols With Changes in Global Cognition and Several Cognitive Abilities,” Neurology.org, Nov. 22, 2022

Prior research has investigated the association between cognition and flavonoids, which are bioactives found in foods that are known to possess anti-inflammatory and antioxidant properties. Researchers in this study set out to further this research by investigating the association of dietary intakes of total flavonols and constituents (such as kaempferol, quercetin, myricetin and isorhamnetin) and the change in cognitive performance. This was measured in global cognition, episodic memory, semantic memory, visuospatial ability, perceptual speed and working memory.

Researchers followed 961 Chicagoans ranging in age from 60 to 100 years old for an average of 6.9 years. Each participant’s diet was assessed using a validated semi-quantitative food frequency questionnaire. Additionally, cognitive performance was annually assessed using a group of 19 standardized tests. Flavonol intake was continuously analyzed using linear mixed effects models. Cognitive domain scores were degenerated on baseline calorie-adjusted flavonol variables.

Results of the study showed that a higher dietary intake of total flavonols and flavonol constituents were linked with a slower rate of decline in global cognition and multiple cognitive domains. Models were adjusted for age, sex, education, APOE-ɛ4, late life cognitive activity, physical activity and smoking. These adjusted models showed that flavonol intake was associated with a slower decline in global cognition, episodic memory, semantic memory, perceptual speed and working memory. Additionally, an analysis of individual flavonol constituents demonstrated that intakes of kaempferol and quercetin were associated with slower global cognitive decline. Myricetin and isorhamnetin were found not to be associated with global cognition.

The results of this study suggest that the dietary intakes of total flavonols and several flavonol constituents are possibly associated with the slower decline in global cognition as well as multiple cognitive abilities with older age.