In a recent study published in the journal Dr nutrients, The researchers investigated the relationship between berry consumption and physiological dysregulation, as measured by the allostatic load (AL) score, using publicly available data from the 2003 National Health and Nutrition Examination Survey (NHANES) conducted in the US adult population. – 2010.
Study: Berry consumption in relation to allostatic load among US adults: The National Health and Nutrition Examination Survey, 2003–2010. Image credit: Bojsha/Shutterstock.com
The AL multisystem measurement framework uses 14 biomarkers from multiple physiological systems, including the cardiovascular, autonomic, metabolic, and immune systems, to measure the severity of physiological dysregulation due to cumulative effects of stressors overall and on specific systems.
A higher AL score, calculated by summing the risk indices for each biomarker within each domain, indicates more dysregulation due to stress, which manifests as physical and cognitive decline, poorer stress-related health conditions such as mental disorders (eg, depression). can do , diabetes, cardiovascular disease (CVD), cancer, and even mortality.
Berries contain high levels of specific polyphenols and other nutrients that have attracted the attention of researchers because they protect against inflammation and cardiometabolic diseases due to their powerful antioxidant properties.
Raspberries and blackberries have the highest levels of the polyphenol ellagic acid, while strawberries have the highest levels of anthocyanins.
In this study, researchers hypothesized that eating more berries would lower AL scores.
They collected data from US adults enrolled in the 2003–2010 NHANES, including demographic, dietary, and medical information through home interviews, mobile examination center (MEC) visits, and phone interviews.
Trained workers then measured their total berry intake using two 24-hour dietary recalls.
People often eat berries as a mixed and processed food. So, the team used an algorithm to identify berry consumption from food records, and those who consumed at least one cup equivalent of berries or berry subtype fruits (strawberries and blueberries) at the meal recall were considered berry consumers.
The researchers used population weight-adjusted multivariable linear regression models to assess the effect of berry intake on AL composite scores and biomarkers.
These models are adjusted for potential confounders, such as age, dietary and sociodemographic, and lifestyle factors.
Of the 15,620 US adults who completed two 24-hour recalls, only 7,684 participated in the morning test and provided complete information on AL biomarkers.
Of these, ~19.3% of adults (n=1485), including 61.9% women, were berry consumers.
Berry consumers, that is, those who ate strawberries, blueberries or any berry, had significantly lower mean AL composite scores than non-consumers.
The association between greater berry intake and lower mean AL composite scores was dose-dependent (P-trend < 0.05) and remains robust after adjusting for all founders.
Compared to non-users, berry consumers had lower levels of biomarkers in each AL domain. Accordingly, the mean cardiovascular and metabolic domain scores for total berry consumers were 4.73 and 2.97 vs. 4.97 and 3.1 for non-consumers.
Compared to non-consumers, strawberry and blueberry consumers had cardiovascular and metabolic domain scores of 4.73 vs . 4.95; 2.99 vs. 3.1; 4.6 vs. 4.95; 2.92 vs. 3.11, respectively.
Berry consumers also had significantly lower mean AL immune and autonomic scores (1.52 vs. 1.56) and (2.49 vs. 2.57), respectively, than non-consumers.
However, this varies slightly with the type of berry eaten. Thus, although blackberry consumers had significantly lower mean autonomic scores than non-consumers, no difference was observed for total berry consumers.
Additionally, blackberry consumers had lower triglyceride and C-reactive protein (CRP) levels, while cranberry juice consumers had lower pulse rates and lower white blood cells.
Furthermore, blueberry, strawberry, and raspberry consumers had lower fasting glucose, fasting insulin, triglycerides, and homeostatic model assessment of insulin resistance (HOMA-IR) than nonconsumers.
The results of the present study suggest that berry consumption is associated with lower AL composite and domain scores and may potentially reduce stress-related physiological dysregulation and prevent cardiovascular and metabolic disorders in the US adult population.
Consistent with previous studies, these findings may be attributed to the protective effects of flavonoids, polyphenols, and other components in berries that act against multisystemic dysregulation.
Specifically, polyphenols interact with the gut microbiota through the gut-brain-axis signaling pathway to increase resilience to stress-induced physiological dysregulation.
Similarly, anthocyanins, a type of flavonoid, have beneficial effects on cardiometabolic factors. In addition, whole berries are rich in dietary fiber, which slows down glucose absorption.
Future research should further validate these findings using different assessment methods in different population groups.