Category: 8. Health

Dietary acid load (DAL) significantly decreased on a low-fat vegan diet and was linked with weight loss compared with a Mediterranean diet among participants in a randomized cross-over trial (NCT03698955) conducted by the Physicians Committee for Responsible Medicine. The findings, published in Frontiers in Nutrition, showed the alkalizing effect of a vegan diet in promoting weight loss.^1-3

Effects of Dietary Acid Load

DAL refers to the body’s overall acid-base balance influenced by diet, and a high DAL has been previously linked with chronic low-grade metabolic acidosis, inflammation, and obesity. Foods like meat, fish, eggs, cheese, and some grains produce acid in the body, whereas most fruits and vegetables have an alkalizing effect. Alkaline diets, including vegan diets, are linked to health benefits such as weight loss, insulin sensitivity, and lower blood pressure.¹

Researchers use the Potential Renal Acid Load (PRAL) to estimate the effect of food on the pH balance, based on 5 nutrient values, including protein, phosphorus, potassium, magnesium, and calcium, along with the Net Endogenous Acid Production (NEAP) to further adjust for an individual’s height and weight to estimate DAL. To further assess how dietary patterns affect DAL, the researchers compared Mediterranean and low-fat vegan diets and whether the impact is connected to changes in body weight.^1,2

Mediterranean Diet vs Vegan Diet

A total of 62 individuals who were overweight were included in the trial and were randomly assigned to follow a Mediterranean or a low-fat vegan diet for 16 weeks, separated by a 4-week washout, before switching to the opposite diet. In the Mediterranean diet, individuals followed the PREDIMED protocol, which involves fruits, vegetables, legumes, nuts or seeds, fish or shellfish, and white meat over red meat, with the use of 50 g of extra virgin olive oil daily. For the low-fat vegan group, individuals consumed vegetables, grains, fruits, and legumes. Outcomes were measured at weeks 0, 16, 20, and 36 as individuals were instructed to complete a 3-day food diary.¹

The results demonstrated that PRAL and NEAP significantly decreased on the vegan diet (95% CI −35.4 to −18.7) compared with no change on the Mediterranean diet (95% CI −34.1 to −17.5). Additionally, body weight was reduced by 6.0 kg, or 13.2 pounds, on the vegan diet, compared with no change on the Mediterranean diet.¹

The findings suggest that over the initial 16 weeks of the study, a reduction in DAL measured by PRAl and NEAP was directly linked to reductions in body weight. This association weakened slightly when accounting for changes in calorie intake. In the subsequent 16 weeks, the positive association between a reduced DAL and weight loss became even stronger and remained significant even after adjusting for calorie intake.¹

“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,” Hana Kahleova, MD, PhD, director of clinical research at the Physicians Committee and lead author of the study, said in a news release. “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.”²

REFERENCES

1. Kahleova, H., Maracine, C., Himmelfarb, J., Jayaraman, A., Znayenko-Miller, T., Holubkov, R., & Barnard, N. D. (2025). Dietary acid load on the Mediterranean and a vegan diet: a secondary analysis of a randomized, cross-over trial. Frontiers in Nutrition, 12, Article 1634215. https://doi.org/10.3389/fnut.2025.1634215

2. Vegan diet improves dietary acid load, a key risk factor for diabetes, new study finds. EuerkAlert!. News release. June 26, 2025. Accessed July 1, 2025. https://www.eurekalert.org/news-releases/1088985

3. Low-Fat Vegan Diet Versus a Mediterranean Diet on Body Weight. ClinicalTrials.gov: NCT03698955. Updated September 27, 2024. Accessed July 1, 2025. https://clinicaltrials.gov/study/NCT03698955

Air pollution exposure can be a key contributing factor to increasingly diffuse myocardial fibrosis, according to cardiac magnetic resonance imaging (MRI) findings from a new study.

For the retrospective study, recently published in Radiology, researchers reviewed cardiac MRI data for 694 patients (mean age of 47), including 493 people with dilated cardiomyopathy (DCM) and 201 people with normal cardiac MRI.

In a multivariable analysis, the study authors found that for patients with DCM, each 1 µg/m³ increase in one-year mean exposure to ambient fine particulate matter with 2.5-µm or smaller aerodynamic diameter (PM_2.5) corresponded to a 30 percent higher native T1 z score.

The researchers also noted that each 1 µg/m³ increase in one-year mean exposure to PM_2.5 was associated with a 27 percent higher native T1 z score in people with normal cardiac MRI findings.

“In line with other studies, our results indicate that adverse effects of fine particulate air pollution on the heart are observed at exposures below current air quality guidelines, reinforcing that there are no safe exposure limits. Our results bolster evidence that air pollution is a modifiable risk factor for cardiovascular disease,” noted study co-author Kate Hanneman, M.D., MPH, FRCPC, an associate professor and vice chair of research with the Department of Medical Imaging at the University of Toronto, and colleagues.

Late gadolinium enhancement (LGE) was 25 percent more likely for each 1 µg/m³ increase in one-year mean exposure to PM_2. in patients with DCM, according to the study authors.

The researchers also found that the association between ambient PM_2.5 exposure and native T1 z scores was particularly prevalent among women (β coefficient of 49 percent), people with hypertension (β coefficient of 48 percent) and smokers (β coefficient of 43 percent).

“Myocardial fibrosis is irreversible; therefore, it is imperative to implement measures to reduce exposure to long-term air pollution, especially in the most vulnerable patients,” emphasized Hanneman and colleagues.

Three Key Takeaways

1. Air pollution correlates with myocardial fibrosis. Each 1 µg/m³ increase in PM_2.5 exposure over one year was linked to a 30 percent higher native T1 z score in patients with dilated cardiomyopathy (DCM) and a 27 percent increase in individuals with normal cardiac MRI findings, indicating diffuse myocardial fibrosis.
2. Risk is heightened in vulnerable subgroups. Stronger associations between PM_2.5 exposure and elevated native T1 z scores were observed in women (49 percent), individuals with hypertension (48 percent), and smokers (43 percent).
3. Pollution exposure linked to structural heart changes. Among patients with DCM, each 1 µg/m³ increase in PM_2.5 exposure was associated with a 25 percent higher likelihood of late gadolinium enhancement (LGE), further indicating structural myocardial injury.

In an accompanying editorial, Davis M. Vigneault, M.D., D.Phil, said the study builds upon previous biochemical and epidemiological studies demonstrating elevated cardiovascular risks with air pollution exposure.

“… This study provides new and compelling evidence for a potential pathologic mechanism by which fine particulate matter pollution increases cardiovascular risk, tying together biochemical evidence implicating PM2.5 in the induction of myocardial fibrosis with epidemiologic evidence associating PM2.5 with morphologic changes and increased cardiovascular morbidity and mortality,” wrote Dr. Vigneault, who is affiliated with the Department of Radiology at the Stanford University School of Medicine in Stanford, Ca.

(Editor’s note: For related content, see “Could Cardiac MRI Improve Risk Stratification in Patients with Dilated Cardiomyopathy?,” “Stress Cardiovascular MRI: What a New Meta-Analysis Reveals” and “Multimodal AI with CCTA and MRI Data Shows Promise in Predicting MACE in Patients with Obstructive CAD.”)

Beyond the inherent limitations of a single-center retrospective study, the study authors conceded possible differences with respect to the timing of exposure to PM_2.5, and potentially unknown confounding factors that may have affected the results. The researchers acknowledged that indoor PM_2.5, ozone and nitrogen dioxide exposures were not assessed. They also noted that the COVID-19 pandemic occurred within the study period.

A study involving 76 primary care practices in Colorado explored two different approaches to initiating continuous glucose monitor (CGM) use with their diabetic patients.

The study from the University of Colorado Anschutz Medical Campus was published in BMC Primary Care. Some practices chose a self-guided option using educational tools developed by the American Academy of Family Physicians. Others referred patients to a virtual CGM initiation service run by a team of primary care-based healthcare professionals who were part of the research team.

Practices with in-house diabetes care and education specialists, formerly known as diabetes educators, were more likely to choose the self-guided route, while those without specialists preferred the study’s virtual service. Other than this difference, the practices were largely similar.

The researchers found that practices had success with both models in boosting use of CGM. 
“This is great news for people with diabetes, especially those who don’t have easy access to a diabetes specialist,” said Kimberly Wiggins, M.A., M.Ed, the lead author on the study, in a statement. “It shows that novel approaches can be developed to share resources, including diabetes care and education specialists, to start patients on CGM and then transition them back to their primary care practice.”

Despite their potential benefits, fewer than half of primary care doctors in the United States have ever prescribed a CGM.

“Our goal was to find practical approaches to help primary care clinics offer CGMs to their patients,” said Tamara Oser, M.D., senior author of the study and professor, in a statement. Oser is director of the Primary Care Diabetes Lab in the Department of Family Medicine at the University of Colorado School of Medicine. “We found that both methods worked. Even clinics without in-house diabetes experts were able to successfully offer CGM by using the remote option.”

Oser noted that this is now the standard of care for many people with type 1 or type 2 diabetes, no matter where they live or what kind of clinic they go to. “This is another huge step in better treatment for the 38 million people living with diabetes in the U.S.,” she added. 

Imperceptible electrical signals delivered to the brain can improve college students’ mathematics skills, a new study has found.

The researchers say that the technology is not far from being ready for at-home use — though one expert emphasized that more research is needed.