32:14 – Dr. Patrick explains the diversion of resources from regular brain function to repair functions. If there is some sort of chronic injury, there is a lot of energy required to facilitate repair and energy is finite. Normal functions don’t get the resources required and this manifests itself as an inability to function normally.
Polymorphisms; Alzheimer’s; APOE4
35:06 – Dr. Patrick covers polymorphisms and the genetic predisposition some people have towards neurodegenerative diseases. A polymorphism is a slight change in the sequence of a gene and this slight change alters the function of that gene somewhat. From an evolutionary standpoint, polymorphisms are are changes that are selected unlike mutations which are random. Some polymorphisms seem counterproductive but Dr. Patrick believes that there could be a reason they exist and therefore there may be some benefit that we don’t understand. ApoE3 is a polymorphism in a gene responsible for transport and repair and the majority of the population has this variation. People with the ApoE4 variation (25% of the population) have a 2-3 fold increase risk of alzheimer’s. People with the ApoE4 variation and a traumatic brain injury suffer a 10 fold increase risk of getting alzheimer’s.
40:10 – ApoE4 in detail. With this variation of the gene, you cannot repair damage as easily. One solution is to literally bypass the amyloid beta plaque obstruction in between neurons via neural outgrowth. Neural outgrowth is the growing of neurons to reconnect a connection obstructed by the plaque. Transporting essential fats and material is needed in this outgrowth process and ApoE4 makes it more difficult to transport material. Furthermore, in times of repair, the body will request activity from the genes responsible for repair. If the ApoE4 is the variation that is being called upon, then the negative effects are exacerbated because there are problems with protein aggregation that comes from the ApoE4 variant (another instance of a vicious cycle). You can test if you have this by doing 23andMe.
Decreasing Alzheimer’s Risk
45:34 – How sleep removes amyloid beta plaque. The brain swells because cerebral spinal fluid is being pushed up into the brain and this process pushes out plaque (and other trash) in between neurons. People with ApoE4 really need to make sure they get enough sleep to compensate for the gene variant’s poor performance in cleaning the brain.
47:38 – Nutrition’s role in alleviating the problem. Data shows that obese, type II diabetic, and insulin resistant individuals also have an increased risk for alzheimer’s. This suggests something about not having the right diet can lead to this increase in risk. Figuring out exactly what is responsible in diet is very complicated, but generally there seems to be a link.
48:33 – Obese individuals and type II diabetics have chronic inflammation and in this state, the body secretes inflammatory cytokines. These cytokines cross the blood-brain barrier and cause neuroinflammation. Injecting people with these cytokines result in cognitive decline and depressive symptoms.
50:41 – Autism and the bacteria in the gut. People with autism have a lot of inflammation in the gut, and as discussed prior, this inflammation can produce the cytokines that make their way into the brain.
51:00 – Brain inflammation and E2 series prostaglandins. When inflammation in the brain occurs, E2 series prostaglandins are released and they inhibit the brain’s ability to release serotonin. You cannot release serotonin from a presynaptic neuron; you need the release of serotonin to regulate behavior. The subjects who were injected with inflammatory cytokines were given EPA (one of the omega-3s [more on this in previous summaries]) and they did not get the depressive symptoms. EPA effectively inhibits the secretion of E2 series prostaglandins.
Probiotics; Gut Health
53:20 – Probiotics. Consuming bacteria that produce lactic acid in the gut is good for you because it creates an acidic environment where pathogenic bacteria cannot survive. The lactate produced can also be used by the other bacteria in the gut as an energy source.
54:06 – Gut barrier. The mucin barrier in the gut keeps the immune cells and the gut bacteria cells separate. If immune cells are exposed to gut bacteria, they fight them off causing a range of cascading effects such as inflammation which breaks the barrier more and the negative effects increase. You want this barrier to be strong. Eating a lot of sugar can break down the mucin.
55:56 – Gut inflammation. When the barrier becomes weak, a lot of resources are spent to repair the damage caused by inflammation. This results in a deficit of resources in places like the brain and the immune system.