Medical Bulletin 28/Jun/2025

Here are the top medical news for the day:

Eating More Broccoli and Spinach May Cut Long-Term Cardiovascular Risk

A cup and a half of leafy green vegetables could go a long way to addressing atherosclerotic vascular diseases (ASVD’s), new research from Edith Cowan University (ECU), the University of Western Australia and the Danish Cancer Institute has found.

Atherosclerotic vascular diseases are a subgroup of cardiovascular disease, which are current leading causes of death world-wide, primarily due to heart attacks and strokes.

In a study of 1,436 older women (average age 75), researchers found that higher dietary vitamin K1 intake may be linked to better heart health. Using food questionnaires from 1998, they assessed vitamin K1 levels and later measured artery thickness (a sign of early atherosclerosis) in over 1,000 participants. Over 14.5 years, hospital records were analyzed, showing that women with higher vitamin K1 intake had fewer atherosclerotic vascular events.

Research led by Ms Dupuy has found that the higher dietary intake of Vitamin K1 could reduce the risk of atherosclerotic vascular diseases.

“Leafy green and cruciferous vegetables, like spinach, kale and broccoli, contain Vitamin K1 which may assist in preventing vascular calcification processes that characterise cardiovascular disease. The great news is that these vegetables can be easily incorporated into your daily meals” she said.

In addition to its’ potential role in vascular calcification inhibition, Vitamin K may also be beneficial for musculoskeletal health, through its impact on bone strength.

ECU Senior Research Fellow Dr Marc Sim noted that a cup and a half of such vegetables is an easy way to increase our daily vitamin K intake and may lower our risk for cardiovascular disease”.

“This research found women who consumed approximately 30% higher intakes of Vitamin K1 than currently recommended in the Australian Dietary Guidelines had lower long-term risk of ASVD,” he said.

“Of importance, when we examined the blood vessels in the neck, those with a higher Vitamin K1 intake also had less thickening of these blood vessels, a marker of atherosclerosis.”

Reference: Dupuy, M., Zhong, L., Radavelli-Bagatini, S. et al. Higher vitamin K1 intakes are associated with lower subclinical atherosclerosis and lower risk for atherosclerotic vascular disease-related outcomes in older women. Eur J Nutr 64, 171 (2025). https://doi.org/10.1007/s00394-025-03686-x

Can a Vegan Diet Boost Weight Loss More Than the Mediterranean Diet?

A low-fat vegan diet significantly lowers dietary acid load and supports weight loss more effectively than a Mediterranean diet, according to a new randomized crossover trial published in Frontiers in Nutrition.

“Eating acid-producing foods like meat, eggs, and dairy can increase the dietary acid load, or the amount of acids consumed, causing inflammation linked to weight gain,” says Hana Kahleova, MD, PhD, director of clinical research at the Physicians Committee and lead author of the study. “But replacing animal products with plant-based foods like leafy greens, berries, and legumes can help promote weight loss and create a healthy gut microbiome.”

The trial included 62 overweight adults who were randomly assigned to follow either a Mediterranean diet or a low-fat vegan diet for 16 weeks. After a four-week washout period, participants switched to the alternate diet for another 16 weeks. Researchers tracked participants’ dietary intake and calculated dietary acid load using two widely accepted indicators Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP). Higher scores reflect a higher acid load, which is linked to inflammation and metabolic disorders.

The results revealed that PRAL and NEAP scores decreased significantly on the vegan diet but remained unchanged on the Mediterranean diet. This reduction in acid load was directly associated with weight loss, independent of changes in calorie intake. Participants lost an average of 13.2 pounds on the vegan diet, while no significant weight change occurred on the Mediterranean diet.

Animal-based foods like meat, fish, eggs, and cheese increase acid production in the body, contributing to chronic inflammation and disrupted metabolism. In contrast, plant-based diets are more alkaline, and have been linked to improved insulin sensitivity, lower blood pressure, and weight reduction.

The researchers suggest that the alkalizing effect of a vegan diet, which raises the body's pH and reduces acidity, could be a key mechanism behind its metabolic benefits.

Reference: Kahleova H, Maracine C, Himmelfarb J, Jayaraman A, Znayenko-Miller T, Holubkov R and Barnard ND (2025) Dietary acid load on the Mediterranean and a vegan diet: a secondary analysis of a randomized, cross-over trial. Front. Nutr. 12:1634215. doi: 10.3389/fnut.2025.1634215

Overemphasis on Weight Loss May Harm Patients: BMJ Study Finds

Focusing too heavily on weight loss for individuals with a high body mass index (BMI) may do more harm than good, according to experts writing in The BMJ. Dr. Juan Franco and colleagues argue that traditional lifestyle interventions based on calorie restriction and increased physical activity are often ineffective in the long term and may unintentionally reinforce weight stigma, leading to negative health outcomes.

The review highlights that, on average, individuals with higher body weight are unlikely to sustain meaningful weight loss over time through lifestyle changes alone. Moreover, evidence shows these interventions have little impact on reducing cardiovascular events or improving survival.

“Doctors should be prepared to inform individuals seeking weight loss about the potential benefits and harms of interventions and minimise the risk of developing eating disorders and long term impacts on metabolism,” the authors write. They stress that while healthy habits are beneficial, weight alone does not accurately reflect a person's overall health.

The article also warns that focusing on weight can worsen societal weight bias, affecting mental health and promoting disordered eating. Instead, the authors support more holistic, patient-centered approaches like Health at Every Size (HAES), which emphasizes health and well-being without focusing on weight loss.

They conclude that quality care should be tailored to individual needs, regardless of weight. “The main goal is to offer good care irrespective of weight, which means not caring less but rather discussing benefits, harms, and what is important to the patient.”

Reference: Franco J V A, Grundtvig Gram E , Meyer L, Grandi D, Cruzat B, Christiansen L B et al. Beyond body mass index: rethinking doctors’ advice for weight loss BMJ 2025; 389 :e084654 doi:10.1136/bmj-2025-084654