Medical Bulletin 4/February/2026

Historically, men have been diagnosed with heart disease earlier than women, with female sex hormones thought to provide some protection. However, changing lifestyle patterns—including rising obesity, diabetes, and hypertension among women—have raised questions about whether early-life cardiovascular risks are becoming more similar between sexes. This study aimed to clarify when these risk differences begin.

Researchers analyzed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a prospective cohort that enrolled Black and White adults aged 18–30 years from four U.S. cities between 1985 and 1986. Participants were followed for more than 34 years, with cardiovascular events tracked through August 2020.

The primary outcome was new-onset, clinically confirmed CVD before age 65, including heart attack, stroke, heart failure, coronary revascularization, and transient ischemic attack. Cardiovascular health was assessed using the American Heart Association’s Life’s Essential 8 framework, excluding sleep.

Among 5,112 participants, men developed premature CVD significantly earlier than women. Men reached a 5% cumulative incidence of CVD approximately seven years sooner. By age 50, nearly 5% of men had experienced a cardiovascular event, compared with fewer than 3% of women.

Coronary heart disease accounted for most of the disparity, with men reaching a 2% cumulative incidence more than a decade earlier than women. In contrast, stroke risk showed no major sex differences, while heart failure differences emerged later in life.

Sex-based differences in premature CVD emerge in the mid-30s, driven mainly by earlier coronary heart disease in men. The findings underscore young adulthood as a critical window for early cardiovascular prevention in men, while emphasizing the continued importance of heart health across the lifespan for women.

REFERENCE: Freedman, A. A., Colangelo, L. A., Ning, H., Borrowman, J. D., Lewis, C. E., Schreiner, P. J., Khan, S. S., & Lloyd-Jones, D. M. (2026). Sex Differences in Age of Onset of Premature Cardiovascular Disease and Subtypes: The Coronary Artery Risk Development in Young Adults Study. Journal of the American Heart Association. DOI: 10.1161/JAHA.125.044922. https://www.ahajournals.org/doi/10.1161/JAHA.125.044922

Wild Blueberries May Promote Heart and Gut Health, New Review Shows

Decades of research suggest that wild blueberries may support heart, metabolic, gut, and brain health, particularly by improving blood vessel function. A recent scientific review, published in Critical Reviews in Food Science and Nutrition, summarizes findings from 12 human clinical trials over 24 years, alongside preclinical and mechanistic studies, examining how wild blueberries influence cardiometabolic outcomes.

The review originated from a symposium organized by the Wild Blueberry Association of North America (WBANA) in Bar Harbor, Maine, which included twelve experts in nutrition, food science, dietetics, cardiovascular health, cognitive health, gut microbiology, and clinical research. While participants received travel reimbursement, no funding was provided for the development of the review itself.

Key Findings

1. Evidence was strongest for improvements in endothelial function, a key measure of blood vessel health. Benefits were observed after both single servings and prolonged intake, with effects including better blood vessel relaxation and responsiveness.

2. Studies reported encouraging effects on blood pressure, blood sugar, and blood lipids, although the authors emphasize the need for larger, well-controlled trials. Benefits may vary based on baseline health, medications, diet, and individual gut microbiome composition.

3. Wild blueberries contain fiber and polyphenols, most of which reach the colon intact. Gut microbes metabolize these compounds into bioactive metabolites, accounting for up to 40% of circulating active compounds. A six-week clinical study showed increased beneficial Bifidobacterium species after daily consumption of 25 grams of freeze-dried wild blueberry powder.

4. Intervention studies in older adults suggest improvements in thinking speed and memory, potentially linked to better vascular function and overall cardiometabolic health.

Wild blueberries support multiple biological pathways, including: Nitric oxide signaling for circulation, Modulation of inflammation and oxidative stress, Lipid and glucose metabolism, Gut microbiome interactions

Overall, the review highlights wild blueberries as a nutrient-dense food with evidence-based potential to improve vascular, metabolic, gut, and cognitive health. Further research is needed to optimize dosing, understand individual responses, and confirm long-term benefits.

REFERENCE: Sarah A. Johnson, Dorothy Klimis-Zacas, Arpita Basu, Bradley W. Bolling, Rafaela G. Feresin, Shirin Hooshmand, Peter J. Joris, Zhaoping Li, Mary Ann Lila, April J. Stull, Pon Velayutham Anandh Babu, Tiffany L. Weir. Wild blueberries and cardiometabolic health: a current review of the evidence. Critical Reviews in Food Science and Nutrition, 2026; 1 DOI: 10.1080/10408398.2025.2610406

Scientists Discover Protein That May Repair Leaky Gut, Reduce Depression

Scientists have identified a potential biological connection between chronic stress, gut health, and depression, with a protein called Reelin emerging as a central player. New research from the University of Victoria (UVic), published in Chronic Stress, suggests that therapies targeting Reelin could simultaneously restore gut barrier integrity and reduce depressive symptoms.

The gastrointestinal system, including the stomach and intestines, regulates which nutrients enter the bloodstream. Chronic stress and stress-related conditions, such as major depressive disorder (MDD), can disrupt this balance, leading to increased gut permeability, commonly referred to as "leaky gut."

Leaky gut allows harmful bacteria and toxins to escape into the bloodstream, triggering inflammation that can exacerbate depressive symptoms. Strengthening the gut barrier may therefore offer a strategy to reduce the severity or risk of MDD.

Reelin is a glycoprotein found throughout the body, including in the brain, blood, liver, and intestines. According to Hector Caruncho, professor of medical sciences at UVic and corresponding author of the study, Reelin may play a key role in maintaining gut and brain health.

In preclinical models, chronic stress reduced Reelin levels in the intestines. Remarkably, a single intravenous injection of 3 µg of Reelin restored these levels to normal. Previous research has also shown that individuals with MDD have lower Reelin levels in the brain, and rodents exposed to chronic stress exhibit similar reductions. In these animals, Reelin administration produced antidepressant-like effects.

Reelin supports the renewal of gut lining cells, which are naturally replaced every four to five days to maintain intestinal integrity. By reinforcing gut barrier function, Reelin may prevent inflammation caused by leaked gut material, potentially reducing depressive symptoms triggered by immune responses.

Ciara Halvorson, a neuroscience PhD student at UVic and first author of the study, emphasizes that these findings could have important implications for individuals living with both depression and gastrointestinal conditions.

Although further research is needed before Reelin-based therapies can be tested in clinical settings, this study highlights a promising new approach to treating depression. By simultaneously targeting the brain and gut, Reelin could offer a more comprehensive strategy for managing mental health conditions associated with chronic stress.

REFERENCE: Ciara S Halvorson, Carla Liria Sánchez-Lafuente, Brady S Reive, Lara S Solomons, Josh Allen, Lisa E Kalynchuk, Hector J Caruncho. An Intravenous Injection of Reelin Rescues Endogenous Reelin Expression and Epithelial Cell Apoptosis in the Small Intestine Following Chronic Stress. Chronic Stress, 2025; 9 DOI: 10.1177/24705470251381456