Low-Carb and Low-Fat Diets Linked to Better Heart Health When Plant-Based

Conventional wisdom often suggests limiting fat and carbohydrates to reduce heart disease risk. Still, recent research indicates a more nuanced picture. A large new study suggests that both low-carbohydrate and low-fat diets can be associated with a lower risk of heart disease, but only when they are rich in high-quality, plant-based foods and low in animal products.

The Role of Diet Composition

Zhiyuan Wu, an epidemiologist at the Harvard T.H. Chan School of Public Health, emphasizes that it’s not simply about reducing carbs or fat. The composition of the diet is crucial. “It’s not just about less carbohydrates or fat,” Wu stated in an email. The research highlights the importance of focusing on the source of these macronutrients.

Research Findings on Cognitive Decline and Heart Failure

Recent research led by Zhiyuan Wu and colleagues investigated the relationship between heart failure and cognitive decline. A 20-year, population-based cohort study published in the Journal of Prevention of Alzheimer’s Disease (February 2026) found that incident heart failure was associated with subsequent decreases in global cognition, memory, or executive function. The study also revealed that the rate of cognitive decline accelerated in the years following a heart failure diagnosis. Interestingly, the rate of cognitive decline before a heart failure diagnosis was similar for those who experienced heart failure and those who did not.

The study, utilizing data from the Health and Retirement Study, included 12,850 adults (average age 66.1 years, 61.8% women). Researchers used linear mixed-effects models to estimate changes in cognition, adjusting for pre-heart failure cognitive trajectories and potential confounding factors. The findings suggest that preventing heart failure may be important in reducing long-term cognitive decline.

Zhiyuan Wu’s Research and Expertise

Zhiyuan Wu is a postdoctoral research fellow in Nutrition at the Harvard T.H. Chan School of Public Health, specializing in Epidemiology. Google Scholar shows Wu has been cited in 2,336 publications. ScienceDirect indicates Wu has 1,843 citations from 1,705 documents.

Practical Dietary Advice

While specific dietary recommendations vary, the research suggests prioritizing whole, plant-based foods. This includes fruits, vegetables, whole grains, and legumes, while limiting the intake of animal products.

Key Takeaways

• Both low-carbohydrate and low-fat diets can be heart-healthy.
• The quality of the diet matters more than simply restricting carbs or fat.
• Plant-based foods should form the foundation of a heart-healthy diet.
• Preventing heart failure may help preserve cognitive function.

Further research is ongoing to refine our understanding of the complex relationship between diet, heart health, and cognitive function. Adopting a diet rich in plant-based foods remains a cornerstone of preventative health strategies.