Ketogenic is a new word for me, as NewScientist‘s Clare Wilson explains (28 November 2015, paywall):
But the high-fat “ketogenic” diet can be an effective last resort method of reducing seizures in people with epilepsy that doesn’t respond to drugs, and may even help a range of other brain conditions. Now researchers may have figured out how it works — and how to make the method more palatable. …
Two-thirds of those who try it see their number of seizures fall by half or more. In some cases, as happened for Matthew, children can later be weaned off the diet without their epilepsy becoming worse again.
Until now, the mechanism behind these effects had been a mystery. Now researchers have discovered that one of the breakdown products of fat binds to molecules on the surface of brain cells, calming the storm of electrical activity that can cause epileptic seizures.
The critical component may be decanoic acid:
Now laboratory tests using frog cells have shown that decanoic acid directly binds to a molecule that is found on the surface of brain cells and is known to be involved in spreading electrical impulses between different neurons. When decanoic acid binds to it, it reduces the flow of electrical current into the cell via this molecule. “It reduces the chance of a neuron firing,” says Robin Williams of Royal Holloway, University of London.
Given this effect that a high fat diet can have on the brain, I have to wonder about other cognitive effects – and how the long running recommendations for a diet low in fat has affected cognitive function. EurekAlert! (ugh) recently published an article on how fats in the diet affect rats:
High-fat feeding can cause impairments in the functioning of the mesolimbic dopamine system, says Stephanie Fulton of the University of Montreal and the CHUM Research Centre (CRCHUM.) This system is a critical brain pathway controlling motivation. Fulton’s findings, published today in Neuropsychopharmacology, may have great health implications. “Our research shows that independent of weight gain and obesity, high-fat feeding can cause impairments in the functioning of the brain circuitry profoundly implicated in mood disorders, drug addiction, and overeating – several states and pathologies that impinge on motivation and hedonia,” Fulton explained. Hedonia relates to a mental state of wellbeing. “Another key finding is that the effects of prolonged high-fat feeding to dampen the sensitivity of this brain reward system are specific to saturated fats – palm oil used in this study – but not monounsaturated fat such as the olive oil used in this study.”
An interesting finding, if it holds. Of course, animal model translation to human models is always a little tricky. In a related finding from the University of Oxford, high fat diets may also lower overall body performance. The summary?
High-fat diet consumption also increased subjects’ simple reaction times (P<0.01) and decreased power of attention (P<0.01). Thus, we have shown that a high-fat diet blunts whole-body efficiency and cognition in sedentary men. We suggest that this effect may be due to increased respiratory uncoupling.
Power of attention? Something akin to ADD, perhaps. Although the ADHD (ADD + Hyperactivity) lady I once dated was quite slender…. perhaps burning off the fat through her hyperactivity. But as I recall, she was not a big eater.
