Journal Digest: Mediterranean Diet and Brain Aging, LAI Antipsychotics in Youth, and More

The Mediterranean diet—one rich in fish, olive oil, fruits, vegetables, and whole grains—has long been linked to improved cardiovascular health. Now a study in Nature Aging suggests the diet may also help slow brain aging by providing certain nutrients that promote brain integrity.

Researchers at the University of Illinois and colleagues first assessed brain health of 100 healthy adults aged 65 to 75 years via cognitive testing and comprehensive imaging of brain structure, connectivity, and metabolism. This enabled them to divide participants into two groups according to phenotype, 64 with accelerated brain aging relative to chronological age and 36 with slowed brain aging. Next, the researchers examined the participants’ nutritional status using blood-based biomarkers, rather than relying on the participants to report their diet.

The researchers found that the group with slower brain aging had higher amounts of blood biomarkers of the following nutrients:

These nutrients are common in the Mediterranean diet. Furthermore, participant characteristics such as demographics, fitness levels, and anthropomorphic measures (weight, height, hip, and waist circumference) did not account for the observed differences in brain aging.

“The present study identified a specific profile of nutrients that may promote healthy brain aging, motivating further research to establish and validate these findings in the context of a randomized, controlled trial,” the researchers wrote. “By building upon the observed findings, future research can inform the development of more effective, targeted dietary interventions.”

Apathy and depression are both common after traumatic brain injury (TBI). However, in older adults with a history of TBI, apathy has a stronger relationship to cognitive functioning than depression does, a study in the Journal of Neuropsychiatry and Clinical Neurosciences in Advance suggests.

Researchers at Thomas Jefferson University in Philadelphia analyzed data from questionnaires completed by 106 adults aged 50 years or older who sustained a moderate to severe TBI at least one year prior. The questionnaires assessed apathy, depression symptoms, health-related quality of life, and societal participation. The participants also completed neuropsychological tests in three cognitive domains: episodic memory, processing speed, and executive functioning.

Overall, around 25% of the participants had both apathy and depression, 25% had only apathy, and 50% had neither (two adults had depression only). The researchers did not find any significant relationships between depression severity and any of the three cognitive domains. However, after adjusting for demographics and type of injury, they found a small but statistically significant relationship between apathy and executive functioning. The researchers found that both apathy and depression made significant unique contributions to health-related quality of life. Only depression had an effect on societal participation.

“Clinically significant levels of both [apathy and depression] appear to be common in this population, and each may have potentially unique implications for psychosocial outcomes, particularly subjective quality of life,” the researchers wrote. “This highlights the importance of targeted clinical evaluation of both symptomatologies among these individuals to better capture and mitigate sources of psychosocial difficulty.”

One in four people aged 16 years or older who take insulin to manage their diabetes have symptoms of an eating disorder, including skipping insulin doses to lose weight, a meta-analysis in Eating Behaviors suggests.

Researchers at Kuopio University Hospital in Finland and colleagues examined data from 45 studies that included 11,592 people aged 16 years or older who took insulin for their diabetes (primarily type 1 diabetes). The studies used a variety of screening tools to assess symptoms of eating disorders, most commonly the Diabetes Eating Problems Survey–Revised (DEPS-R). The studies were drawn from around the world, and 10 studies included only females.

The overall prevalence of eating disorder symptoms was 24%, whereas the prevalence in the 20 studies that used the DEPS-R was 27%. In studies in which more than 58% of the participants were female, the prevalence of eating disorder symptoms was 30%, compared with 18% in studies with fewer female participants.

In an additional meta-analysis of 13 studies involving 2,210 people, the prevalence of insulin omission was 21%.

“The future aim should be to identify patients with eating disorder symptoms by systematic screening, since concurrent eating disorder and type 1 diabetes increase the risk of diabetic complications, admission rates to [the] hospital, and even the risk of death when compared with patients with type 1 diabetes but without an eating disorder,” the researchers wrote.

Long-acting injectable antipsychotics (LAIAs) may reduce the risk of hospital readmission of pediatric patients compared with oral antipsychotics, according to a study in Mental Health Clinician.

Researchers at Rutgers, the State University of New Jersey, conducted a retrospective chart review to evaluate readmission rates for 76 pediatric patients with an average age of about 16 years who were admitted to a psychiatric ward in a large academic hospital and required antipsychotic medications. The admissions were between January 1, 2015, and December 1, 2022. Half of the patients received LAIAs and half received oral antipsychotics.

Hospital readmission rates for the LAIA group within the first three months of discharge were about half that seen in the oral antipsychotics group (13.2% versus 26.3%). Readmission rates were also lower for the LAIA group through six months and 12 months. Overall, 23.7% of youth in the LAIA group and 47.4% in the oral antipsychotics group had at least one readmission within one year of discharge.

The LAIA group also had a decreased incidence of side effects when compared with the oral antipsychotics group, which the researchers noted may be attributable to longer durations of action with LAIA medications and short hospital stays with less monitoring time.

The researchers noted that the sample size was small, which likely affected the statistical significance of several outcomes.

“[A]dditional studies with larger sample sizes focusing on individual disease states are warranted,” they wrote. “Whereas long-term tolerability of oral formulations is well-studied in this population, additional research is needed for the LAIA formulations.”

Long-term exposure to particulate matter may increase the risk of dementia, likely by way of promoting inflammation in the brain, according to an analysis of the Danish Nurse Cohort Study in Alzheimer’s & Dementia.

Researchers from the University of Copenhagen and colleagues followed 25,233 female nurses for dementia incidence, ascertained via hospital contact or medication prescription, from 1993 or 1999 until 2020, and estimated air pollution and road traffic noise levels at the nurses’ residences. As part of the main study, the nurses completed surveys about lifestyle factors, socioeconomic status, working conditions, and medical history.

Over the study period, 1,409 of the nurses developed dementia. After the researchers adjusted for lifestyle, socioeconomic status, and road traffic noise, they found that long-term exposure to multiple pollutants (except for ozone) was associated with dementia risk. Exposure to fine particulate matter with a diameter of ≤2.5 µm was most strongly associated with dementia incidence; each increase of 2.6 μg/m3 was associated with 35% increased risk. However, nurses who reported being physically active had a lower risk of developing dementia when exposed to the same levels of particulate matter than those who reported low physical activity.

“[The results bring] strong new evidence that supports existing findings in the current literature, suggesting that air pollution is an important risk factor for dementia,” the researchers wrote. ■