Today’s post is basically a continuation of my series on neurodegeneration. It has been a long series so far, and my plan was to have this be my second last post in the series. However, the more information I gathered, the more I realized I would need to break this topic into multiple posts so I decided to start a new series in which I will specifically address dietary and lifestyle measures we can take to prevent/reduce the risk of neurodegeneration.
My plan of attack here will be to attempt to convince you that certain types of foods can have negative impacts on the areas that I have outlined as possible “causes” of neurodegeneration. This would include, systemic inflammation, autoimmune issues, oxidative stress, mitochondrial dysfunction, metabolic derangement, DNA methylation, etc. If you are not familiar with these topics, please refer back to my previous posts in this series.
- Neurodegeneration: Path to Prevention Part 1 – Introduction
- Frontotemporal Lobar Degeneration: Neurodegeneration The Path to Prevention Part 2
- Type 2 Diabetes Related Dementia: Neurodegeneration the Path to Prevention Part 3
- Alzheimer’s Disease: Neurodegeneration the Path to Prevention – Part 4
Neurodegeneration Prevention – Gluten
If you read my previous post on wheat/gluten you will be well aware that chronic consumption of this food can be particularly bad for our health, even if you don’t have celiac’s disease. Heightened gluten antibodies have been shown in individuals who have non-celiac gluten sensitivity (1, 2), indicating that there is some level of immune dysbiosis present. We also know that ingestion of wheat and other cereal grains containing gluten and gluten-like proteins, can lead to leaky gut and systemic inflammation (3). What we also know is that gluten intake is tied to many autoimmune conditions like rheumatoid arthritis (4), psoriasis (5), other skin conditions (5), and MS (6). If you follow my blog, this is not new stuff as I have discussed it all before; however, what I have not discussed specifically is how gluten is tied to many neurological conditions such as central and peripheral nervous system inflammation, ataxia, peripheral neuropathy, encephalopathy (term for general brain dysfunction), migraine, epilepsy, symptoms and pathology that is indistinguishable from multiple sclerosis (7). I will note that the cited article is a personal view article but it is written more like a review article with plenty of cited sources, and there is plenty of evidence of this elsewhere. Other studies have shown that gluten is related to Huntington’s Disease (8), as well as brain atrophy and dementia (9).
If you have read the posts in this series to date, it will probably be of no surprise to you that a suggestive mechanism of how gluten intake can lead to these conditions is due to gluten’s impact on our immune system. As noted above, gluten can lead to leaky gut, which in turn, causes an increase in systemic inflammatory markers (3). Gluten can also cause elevated systemic inflammation without the presence of leaky gut (3). Regardless, based on previous articles in this series, we are also well aware that elevated systemic inflammation can cross the blood brain barrier and increase brain inflammation…and thus we arrive at the crux of the neurodegenerative disease issue.
Also, keep in mind that most all of the foods that contain gluten have a high glycemic index and glycemic load, and as we all know, over indulgence in foods of this nature can lead to metabolic derangement and obesity (think diabetes), which we know is tied to neurodegeneration. More on this in the sugar section below.
Honestly, the above just touches the surface of what is likely going on when we eat gluten. I anticipate much more research on this in the very near future with gluten free diets becoming so popular. I would be surprised if we don’t start to see gluten tied to irregularity of gene expression, mitochondrial dysfunction and much more. The more I read about this stuff, the more it seems that all these factors really are just a vicious circle. I also wouldn’t be surprised if we start to see more information regarding non-gluten containing cereal grains and negative effects similar to gluten. There is some evidence out there now, but it’s not as incriminating as it is with gluten containing grains. Personally I choose the safe route by never eating gluten…EVER…and significantly limiting all other grain consumption to almost zero.
Dietary Neurodegeneration Prevention – Sugar
I know I don’t have to do too much convincing about the horrible effects of consuming too much sugar, particularly high levels of fructose that is seen in products containing things like high fructose corn syrup and agave (which is very high in fructose).
Fructose is a very interesting sugar in that it has a super power that allows it to easily induce metabolic syndrome; including, insulin resistance, elevated blood pressure, increase serum triglycerides (more on this below), induce fatty liver, and increase visceral fat (10). Interestingly, this has nothing to do with the actual amount of calorie intake. Animals fed the same amount of glucose vs. fructose show totally different metabolic markers where the fructose groups develop metabolic syndrome and and the glucose fed ones did not (10). Another interesting theory is that fructose intake has been linked with intestinal permeability, with a suggestive mechanism of action related to fructose metabolism in the intestines (10). So, why is this all important when talking about neurodegeneration? Well, based on previous articles in the series we know that neurodegeneration is tied to inflammation, metabolic dysfunction, and immune dysfunction, and guess what…metabolic syndrome is linked to chronic systemic inflammation, metabolic dysregulation (obviously), and diabetes (also directly linked to neurodegeneration) while increased intestinal permeability is linked to immune system dysfunction and chronic inflammation, not to mention a whack load of other conditions (a list which continues to grow as more studies are done). Once again we arrive back at the crux of the neurodegenerative disease issue.
Aside from fructose, we also know that obesity and diabetes are tied to chronic systemic inflammation (11, 12) and that these two conditions can be tied to the overconsumption of sugar and high glycemic index foods. On this note, we know that low glycemic index and low glycemic load diets improve markers of inflammation (13, 14) which really should be obvious given they are the opposite if the inflammatory and diabetes promoting high sugar diets. To further this point, very low carbohydrate diets have been shown as therapeutic for obese subjects, leading to reduced markers of metabolic disease such as inflammatory markers and plasma fatty acids (15). Does this mean that we all need to eat very low carb diets…probably not if we are normal weight, metabolically healthy, and active, but it does provide more mounting evidence that we should be limiting our sugar and high glycemic load/index foods as much as possible to reduce inflammation and the possibility of diseases states in the future, including neurodegeneration.
Insulin resistance and pre-diabetes have also been linked to DNA damage and mitochondrial dysfunction (16, 17), and we know the role mitochondria and DNA expression can have on neurodegeneration. Basically, the evidence is pretty clear that we should be eating a lower glycemic index/load diet along with probably a moderate carb intake diet (for healthy people) to limit the neurological issue associated with insulin resistance, diabetes, and prediabetes.
As a final note in the sugar section, I mentioned above that diets inducing diabetes (ie. high glycemic index/load and high fructose) lead to a rise in plasma (blood) fatty acids and lower carbohydrate diets reduce fatty acids in the blood. Well, elevated plasma fatty acids have been shown to directly increase central nervous system inflammation (18). Cool!
So there you have it. Gluten and excess sugar intake is tied both directly and indirectly with neurodegerative disease and is just one other reason for us to limit the intake of these foods as much as we can. I hope you have found the above helpful and informative, my next post in this series will focus on more dietary consideration for the prevention of neurodegeneration (i.e fat, probiotics, etc).
The Barefoot Golfer