A recent study published in Nature Metabolism reveals a potential link between high protein consumption and immune cell activation, contributing to arterial plaque formation, known as atherosclerosis. This study, involving humans, mice, and cells, highlights that consuming more than 22% of daily calories from protein may pose risks.
The amino acid leucine, predominantly found in animal products such as beef and eggs, is identified as a key player in this process. Senior author Babak Razani advises caution, emphasising that indiscriminate protein intake could potentially harm arteries.
"Our hope is that this research starts a conversation about ways of modifying diets in a precise manner that can influence body function at a molecular level and dampen disease risks," he said in a statement.
The study challenges the notion that higher protein intake is always beneficial. Analyzing a decade-long survey of typical American diets, researchers found that a significant portion of daily calories is derived from protein, primarily from meat sources.
While protein is widely acknowledged for its importance in maintaining health, this study suggests that excessive intake may have detrimental effects on long-term well-being.
Collaborating with metabolism expert Bettina Mittendorfer, Razani delved deeper into the investigation. The research encompassed various models, ranging from cellular studies to animal experiments to human observations. Initial assessments with healthy individuals guided the investigation into the timeline of immune cell activation.
Experiments conducted on mice and human cells demonstrated that consuming more than 22% of daily calories from protein could impair macrophages, the cells responsible for debris clearance, ultimately leading to the accumulation of plaque in arteries.
"Perhaps blindly increasing protein load is wrong,” Razani said, adding, "Instead, it’s important to look at the diet as a whole and suggest balanced meals that won’t inadvertently exacerbate cardiovascular conditions, especially in people at risk of heart disease and vessel disorders."
Further research is needed to determine the ideal protein intake, as suggested by the study. Additionally, Razani pointed out that the varying levels of leucine in plant and animal protein-enriched diets could account for the differences in their impact on metabolic and cardiovascular health. "The potential for this type of mechanistic research to inform future dietary guidelines is quite exciting," he said.
Potential health risks of excessive protein intake:
Dehydration: Protein metabolism requires more water, and consuming excess protein can lead to dehydration if proper fluid intake isn't maintained. Dehydration can manifest as fatigue, headaches, and constipation.
Kidney strain: Excess protein breakdown generates nitrogenous waste products, which the kidneys must work harder to eliminate. This increased workload over time can stress the kidneys, especially for individuals with pre-existing kidney issues.
Digestive issues: The body needs sufficient water to digest and absorb protein effectively. Consuming excess protein without adequate hydration can cause constipation, bloating, and other digestive problems.
Bone health concerns: Research suggests a possible link between high-protein diets, particularly those rich in red meat, and increased calcium excretion. This can potentially contribute to bone loss and osteoporosis, although further research is needed to solidify the connection.
Weight gain: While high-protein diets are often associated with weight loss, excessive protein intake can lead to weight gain if it creates a calorie surplus. This is because the body can convert excess protein into energy, leading to storage as fat if not used for immediate needs.
ALSO READ: Plant Protein vs Animal Protein: Which is healthier?
