Medical Bulletin 26/July/2025 - Video

Drinking nitrate-rich beetroot juice can significantly lower blood pressure in older adults, and the effect may be driven by changes in the oral microbiome, according to new research from the University of Exeter. The study, published in Free Radical Biology and Medicine, is the largest of its kind and sheds light on how diet influences vascular health through oral bacteria.

Nitrate, naturally found in vegetables like beetroot, spinach, and celery, is a essential for producing nitric oxide a compound that supports healthy blood vessels. As people age, their bodies produce less nitric oxide, which contributes to rising blood pressure and increased cardiovascular risk. Previous studies have shown that nitrate-rich diets can reduce blood pressure, but this new study focused on whether the effect is mediated by changes in oral bacteria.

Researchers recruited 75 participants 39 adults under 30 and 36 adults aged 60 to 70 through the NIHR Exeter Clinical Research Facility. Each participant drank a concentrated beetroot juice "shot" twice daily for two weeks, followed by a two-week washout period. They also consumed a placebo version of the juice, with the nitrate removed, for two weeks. The team used bacterial gene sequencing to analyze the oral microbiome before and after each treatment period.

In both age groups, the composition of oral bacteria changed significantly after consuming nitrate-rich juice, but the changes were more beneficial in older adults. In this group, levels of harmful bacteria such as Prevotella decreased, while beneficial bacteria like Neisseria increased. Importantly, the older participants who had higher average blood pressure at the start saw a notable reduction in blood pressure after consuming the nitrate-rich juice, but not after the placebo.

Co-author Professor Andy Jones, of the University of Exeter, said: “This study shows that nitrate-rich foods alter the oral microbiome in a way that could result in less inflammation, as well as a lowering of blood pressure in older people. This paves the way for larger studies to explore the influence of lifestyle factors and biological sex in how people respond to dietary nitrate supplementation.”

These findings open new possibilities for managing blood pressure and promoting healthy ageing through diet.

Reference: faculty-of-health-and-life-sciences/beetroot-juice-lowers-blood-pressure-in-older-people-by-changing-oral-microbiome/

Can Your Genes Reveal If You’ll Be Obese as an Adult?

A new study published in Nature Medicine has revealed that genetic analysis using data from more than five million individuals can offer powerful insights into who is at risk of developing obesity even from early childhood. Led by researchers from the Universities of Copenhagen and Bristol, the study introduces a new polygenic risk score (PGS) that could help identify children most likely to benefit from early preventive strategies.

Obesity is a growing global concern, with the World Obesity Federation predicting that over half the world’s population could be overweight or obese by 2035. Despite available treatments such as lifestyle changes, surgery, and medications, their accessibility and effectiveness remain limited. This has intensified the search for early detection and prevention approaches.

To develop the polygenic risk score, the research team analyzed the genomes of over five million people, combining data from sources including the Genetic Investigation of ANthropometric Traits (GIANT) consortium and DNA-testing company 23andMe. The polygenic risk score aggregates the small effects of thousands of genetic variantsmany of which influence appetite via the brain into a single predictive score.

The study found that this polygenic risk score could explain 17% of the variation in body mass index (BMI), making it nearly twice as effective as previous genetic models in predicting obesity. Researchers validated the score using data from over 500,000 individuals, including longitudinal BMI data from participants in the long-running “Children of the 90s” cohort study.

“What makes the score so powerful is the consistency of associations between the genetic score and body mass index before the age of five and through to adulthood timing that starts well before other risk factors start to shape their weight later in childhood,” said Assistant Professor Roelof Smit, lead author from the University of Copenhagen.

The findings point to the potential of integrating genetic screening into early-life healthcare to better identify children at risk and tailor interventions accordingly.

Reference: Smit, R.A.J., Wade, K.H., Hui, Q. et al. Polygenic prediction of body mass index and obesity through the life course and across ancestries. Nat Med (2025). https://doi.org/10.1038/s41591-025-03827-z

Why Grapes Might Deserve a Spot Among Superfoods?

A new article published in the Journal of Agriculture and Food Chemistry is making the case for fresh grapes to be officially recognized as a superfood. Written by Dr. John M. Pezzuto, a prominent resveratrol and cancer researcher and Dean of the College of Pharmacy and Health Sciences at Western New England University, the article argues that grapes meet and exceed the loose criteria often applied to so-called superfoods.

While the term “superfood” lacks a formal scientific definition, it is commonly used to describe foods that are particularly rich in nutrients and associated with multiple health benefits. These foods often include berries, nuts, and vegetables that are staples of the Mediterranean diet. Dr. Pezzuto believes that grapes are often overlooked in this category despite compelling scientific evidence supporting their health benefits.

To build his case, Pezzuto highlights the unique chemical composition of grapes. “Grapes are a natural source of over 1,600 compounds, including antioxidants and other polyphenols such as flavonoids, anthocyanidins, catechins, phenolic acids, resveratrol, and more,” he writes. He emphasizes that the health effects come not from any single compound, but from the synergistic action of the entire grape matrix.

Citing over 60 peer-reviewed studies, the article outlines grapes’ positive impact on cardiovascular, brain, skin, gut, and eye health. Grapes have been shown to promote blood vessel relaxation, improve circulation, and modulate cholesterol levels. Clinical trials also suggest benefits for brain metabolism, resistance to UV damage in skin, microbiome diversity, and even retinal health. Notably, Pezzuto points to findings in nutrigenomics showing that grape consumption can beneficially alter gene expression in several body systems, suggesting that “these activities at the genetic level that are likely the driving force behind the health benefits of grapes.”

Reference: Pezzuto, John M. (2025). Perspective: Are Grapes Worthy of the Moniker Superfood? J. Agric. Food Chem. Doi: 10.1021/acs.jafc.5c05738