Scientists are searching to uncover how molecules related to energy production in the body may influence brain health as we age. What is actually healthy?

In human energy production, ketone bodies, pyruvate, and citrate are vital for energy in the body and connect to our diet. Ketone bodies are produced during fat metabolism, especially in fasting and when eating fewer carbs, such as in ketogenic diets. Pyruvate is a product of carbohydrate breakdown and comes from starchy foods like bread and rice. Citrate, found naturally in citrus fruits, supports energy metabolism as part of the citric acid cycle in cells.

The study
Researchers studied these key metabolites in blood samples from nearly 1,850 older adults. These individuals were part of a long-term health study. Besides blood blood samples, their cognitive abilities were assessed over nine years and brain imaging was conducted during the research period. By analyzing these metabolites, the team sought to understand their links to memory decline, changes in brain structure, and the risk of developing dementia.

The findings of the study were that higher levels of ketone bodies, particularly a molecule called beta-hydroxybutyrate, were linked to faster cognitive decline and an increased likelihood of dying from dementia.

Conversely, higher levels of pyruvate, another molecule central to our natural energy production, were connected to better brain outcomes, including slower memory decline, smaller brain cavities that suggest less tissue loss, and a reduced risk of dementia. Citrate, a molecule involved in cellular energy cycles, also appeared to have protective effects, with higher levels associated with slower cognitive decline and lower dementia risk.

This study highlights the intricate relationship between energy-related molecules in the blood and brain health in older adults.

While ketone bodies may have adverse effects in this context, pyruvate and citrate seem to offer some protection against cognitive decline and dementia. These findings could pave the way for new strategies to preserve brain health through better understanding and potential regulation of these metabolites.

Until then, enjoy a balanced and moderate diet that works for your needs—not too much, not too little.

About the scientific paper:

First author: Laia Gutierrez-Tordera, Spain
Published: Aging and Disease. November 2024.
Link to paper: https://www.aginganddisease.org/EN/10.14336/AD.2024.0754