Researchers have discovered a potential mechanism underpinning the improvements seen in aging male mice on ketogenic diets — “keto diets,” for short.
They have proposed that cycling male mice between a control diet and a ketogenic diet results in an improvement in the signaling that occurs between synapses in the brain.After analyzing two seminal papers published in 2017 that showed its beneficial roles in the overall health of aged mice, including brain performance, researchers decided to study the effect of the ketogenic diet.In these two previous works, the authors showed improvement in specific behavioral tasks routinely used in animal experimentation to evaluate memory and learning.
Such an improvement convinced them to go deeper into the molecular mechanisms that explain that positive response on one side, but also prompted them to include several other assessments at different levels, ranging from the whole organism level to the molecular functions, to understand why the diet was beneficial in aged animals.
To investigate the previous findings further, the researchers kept 19 male mice aged 20–23 months — counting as “old age” in mice — either on a control diet, or on a ketogenic diet cycled with the control diet every other week.For the first 12 weeks the metabolic parameters of these mice were measured, and for 5 weeks after that, mice were kept on their diets and subjected to behavioral testing.
Researchers showed there was improved plasticity in the hippocampus brain region of older mice.
Further testing showed that this improved plasticity seen in mice kept on a ketogenic diet cycled with a control diet was due to a molecule called a ketone body, which is produced when levels of glucose are low, activating a signaling pathway between the synapses.
Researchers say that this concept is fundamental in the aging field because it relates to the difference between lifespan (all our vital trajectory from when we are born until the day we die) and healthspan (the part of our vital trajectory free from chronic diseases).
This can result in a lower intake of fiber, vitamins, minerals, and antioxidants that are important for overall health.Instead of the keto diet, experts generally recommend that older adults follow diets supported by more extensive human research for healthy aging.Questions have been raised previously about the effectiveness of ketogenic diets in women as their metabolisms process fats differently to men.
