What kind of fat does the brain need? Just omega 3 or more than that?
DHA is extraordinarily important for our brains, which are comprised of more than 60% fat. DHA makes up 90% of omega-3 fatty acids in the brain. The brain is unable to manufacture DHA locally and maintains these high DHA levels primarily through the uptake of DHA from lipids in circulating blood that cross the blood-brain barrier. Additionally, we're building strong evidence that E4 carriers need additional amounts of omega-3 fatty acids to reach the same levels as other APOE genotypes.
Another nutrient that is vital for brain health is choline, found in large amounts in foods with relatively high levels of fat like eggs and liver. Choline stimulates the production of acetylcholine, a neurotransmitter responsible for synaptic connections essential to memory. Phosphatidylcholine, a phospholipid (a class of lipids that represents a major component of all cell membranes) of which choline is one component, is reduced in the brains of Alzheimer’s patients; whereas higher levels are associated with memory performance and resistance to cognitive decline. Choline has also been found to aid in the reduction of homocysteine, implicated in both dementia and cardiovascular disease as mentioned earlier. A recent study demonstrated that choline not only improved spatial memory in pregnant mice, but it did so for several generations, without further supplementation, underscoring its neuroprotective importance.The potential lack off these two key nutrients is one (of many) reasons that a low fat vegan diet is especially risky for our genotype.
But It's not the keto warning that interested me in the Sherzai article, it was their statement regarding fat and the brain. I do find it to be an apparent dilemma that the brain supposedly needs fat, yet fat harms its vasculature. No fat for the brain may cause AD; fat clogging arteries in the brain may cause AD. How do we reconcile these two statements?
I think we can pretty easily reconcile those statements by simply avoiding insulin resistance and by choosing high quality fats in the context of an otherwise nutrient dense, clean diet. FWIW, I suspect your claim is based on studies like this
which presume a high fat diet leads to obesity and metabolic syndrome. Sadly, there's almost no research that separates an examination of dietary fat without concurrent high level of carbohydrates, which we all know is a formula for disaster- especially for our genotype. The other thing to take into consideration when thinking about dietary fat, is the role it plays in addressing our significant reduction in neural fuel that precedes and accompanies cognitive decline. Higher levels of healthy fat (especially when combined with a long daily fast and exercise) can safely help create ketones that have been shown to offset our cerebral fuel reduction.