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Does Sugar Raise Alzheimer's Risk?
Disturbing findings reveal how sugar makes brains vulnerable to dementia; Low-carb/high-fat diets look promising 03/16/2017

Scientists at Brown University Medical School posed a radical idea back in 2005.

They’d noticed a striking similarity between diabetes and Alzheimer’s disease — namely, an inability to properly regulate insulin and blood sugar.

By 2008, the Brown University group had concluded that the then-available research supported their idea.

As they wrote, “We conclude that the term “type 3 diabetes” accurately reflects the fact that AD [Alzheimer's disease] represents a form of diabetes that selectively involves the brain …”.

Since then, the evidence that Alzheimer’s is triggered or worsened by excessive sugar intake — an unhealthful hallmark of the standard American diet — has grown considerably.

Now, new research from the Netherlands adds another good reason to avoid sugar — to help avoid Alzheimer’s and ease its impact.

What do diabetes and Alzheimer’s have in common?
Even mild elevation of blood sugar is linked to a higher risk for dementia.

Why would that be?

Insulin is the hormone needed for your cells to absorb sugar (glucose) from the blood. Cells then either store that sugar for future use, or use it to produce immediate energy.

When your cells don’t absorb sugar in response to a normal amount of insulin, this condition is called insulin resistance, and it’s the precursor to full-blown diabetes.

Because your brain depends on blood sugar (glucose) as its primary fuel, insulin resistance threatens the survival of brain cells (neurons).

Insulin also influences the release and reuptake of neurotransmitters, and can thereby affect learning and memory.

So, if your brain cells can’t absorb sugar, this will lead to problems, including dementia.

Even worse, insulin-resistant brain cells lose their ability to detoxify the amyloid-beta proteins associated with Alzheimer’s — thereby causing a deterioration in thinking and memory.

These facts explain the growing evidence that improper regulation of insulin promotes — or even triggers — Alzheimer’s.

For example, diabetics are about twice as likely to develop Alzheimer’s, while brain scans show that greater insulin resistance results in less glucose (brain fuel) in brain areas typically affected by Alzheimer's.

And as Alzheimer’s disease progresses, there's a simultaneous drop in the amount of blood sugar used in key regions of the brain.

Finally, blood glucose and its break-down products can damage proteins in cells, via a reaction called glycation, in which proteins bind to sugars.

Glycation also yields chemicals called “advanced glycation end-products”, which generate chronic inflammation in the body.

The acronym for these chemicals — AGEs — is sickeningly appropriate, because chronic inflammation accelerates aging of cells and tissues.

We’ve reported on past research linking excessive dietary sugars to dementia: See Carbs Fog Aging Brains and Blood-Starved Brains Shown Prone to Alzheimer’s.

And early research suggests that seafood-source omega-3 fatty acids (DHA and EPA) may blunt sugar-related brain damage: See Fructose Harms Brain Genes; Omega-3s Undo the Damage and Sugary Brain Damage Blunted by Omega-3s.

Now, new findings show there’s a “tipping point” beyond which elevated blood sugar levels substantially raise the risk for Alzheimer’s.

New finding: Excess blood sugar disables a brain-protective enzyme
British scientists have discovered that excess blood sugar (glucose) has another bad effect.

They found that excess blood sugar damages an enzyme the body uses to reduce the inflammation known to occur in the early stages of Alzheimer’s.

The new findings come from scientists at Britain's University of Bath and King’s College London.

They examined brain samples from people with and without Alzheimer’s, and discovered that — in the early stages of Alzheimer’s — glycation damages an enzyme called MIF that affects inflammation and insulin alike.

Conversely, when the fatty tissue in obese people releases MIF, the enzyme appears to promote metabolic and inflammatory processes that drive obesity-related damage to health.

However, as Dutch researchers recently reported, “Although many of the findings support a pro-inflammatory role of MIF in disease development, recent reports also provide indications that MIF may exert protective effects under certain conditions.”

The new British findings support that statement, because they show that MIF exerts protective effects against the development of Alzheimer’s disease.

Special brain cells called glia — which support, insulate and feed the neurons involved in thinking and memory — use the MIF enzyme to reduce the build-up of abnormal proteins in the brain that’s a hallmark of Alzheimer’s disease.

The British researchers found that the inhibition and reduction of MIF activity caused by glycation could be the tipping point in disease progression.

And they discovered that as Alzheimer’s progresses, damaging glycation of these protective MIF enzymes increases.

According to study co-author Jean van den Elsen, “Normally, MIF would be part of the immune response to the build-up of abnormal proteins in the brain, and we think that — because sugar damage reduces some MIF functions and completely inhibits others — that this could be a tipping point that allows Alzheimer’s to develop.”

His colleague, Dr. Rob Williams, addressed the possible medical uses of their discovery: “Knowing this will be vital to developing a chronology of how Alzheimer’s progresses and we hope will help us identify those at risk of Alzheimer’s and lead to new treatments or ways to prevent the disease.”

Ketones: Healthier brain fuels from low-carb/high-fat diets?
Paleo- and Atkins-style diets strictly limit intake of sugars and starchy carbs.

Instead, they get many more of their calories from fats and protein: a pattern that allegedly hews closer to the diets eaten thoughout most of human history, except the past 10,000 to 15,000 years.

In fact, the diets of Neanderthals and prehistoric humans remain unclear.

Recent research suggests that they varied widely — from meat-focused to plant-focused — based on a particular group's environment.

And this evidence shows that some Paleolithic diets included very substantial amounts of wild legumes, grasses, and grains ... including cooked grains.

Last, it's increasingly clear that humans can and have adapted to changes in diet over a few thousand years, and that many people thrive on diets relatively high in Paleo-diet "no-nos" like grains and dairy.

Regardless of what certain prehistoric ancestors ate (or didn't), low-carb, high-fat diets may bring some big brain benefits, thanks to chemicals called ketones.

The brain normally runs on glucose stored in the liver as glycogen, but a very-low-carb diet depletes the liver's glycogen supply, prompting the organ to produce alternative, fat-derived fuel in the form of ketones.

This explains why Paleo and Atkins-style diets are sometimes called "ketogenic".

Preliminary clinical evidence suggests that ketogenic diets amply fuel the brain while boosting its performance, with the degree of cognitive enhancement tied to a person's blood ketone levels.

Emerging evidence about the brain damage caused by diets high in sugars and refined carbs suggests that shifting your brain fuel from glucose toward ketones may reduce your risk of Alzheimer's and other forms of dementia, delay their onset, and/or ease their symptoms.

If you decide to try a ketogenic diet, be aware that coconut oil features fats called MCTs, which the body readily converts into brain-fueling ketones.

What should you do?
Dr. Omar Kassaar, a co-author of the new Dutch study, urged people to act on its findings.

As he said, “Excess sugar is well known to be bad for us when it comes to diabetes and obesity, but this potential link with Alzheimer’s disease is yet another reason that we should be controlling our sugar intake in our diets.”

We’d add that it’s smart to avoid refined, sugary carbs — such as white-flour baked goods, white rice, potatoes (except their nutritious skins), and other starchy, nutrient-poor foods.

But for most people, it’s clearly healthful to enjoy modest portions of genuinely whole-grain foods — quinoa, buckwheat, wheat berries, brown or black rice, and coarse whole-grain breads, especially sourdough varieties.

It’s also wise get most of your carbs from colorful vegetables and beans, rich in healthy fibers and antioxidants.

Last, but far from least, low-carb/high-fat diets — such as Paleo- or Atkins-style plans — probably help protect against dementia, and may boost brain performance.

But don't rely on cheap vegetable oils — specifically, corn, soy, sunflower, and safflower — which are high in omega-6 fats. 

That's because the average American's excessive intake of omega-6 fats from harms brain and overall health. (See our Omega Balance page and the Omega-3 / Omega-6 Balance section of our news archive.)

Instead, it makes sense to favor omega-3 fats from fish, monounsaturated fats (avocados, extra virgin olive oil, macadamia nut oil, canola oil), MCTs from coconut oil, and saturated fats.


  • Ahmed S, Mahmood Z, Zahid S. Linking insulin with Alzheimer's disease: emergence as type III diabetes. Neurol Sci. 2015 Oct;36(10):1763-9. doi: 10.1007/s10072-015-2352-5. Review.
  • Crane PK, Walker R, Larson EB. Glucose levels and risk of dementia. N Engl J Med. 2013 Nov 7;369(19):1863-4. doi: 10.1056/NEJMc1311765.
  • Crane PK, Walker RL, Sonnen J, Gibbons LE, Melrose R, Hassenstab J, Keene CD, Postupna N, Montine TJ, Larson EB. Glucose levels during life and neuropathologic findings at autopsy among people never treated for diabetes. Neurobiol Aging. 2016 Dec;48:72-82. doi: 10.1016/j.neurobiolaging.2016.07.021.
  • de la Monte SM, Tong M, Lester-Coll N, Plater M Jr, Wands JR. Therapeutic rescue of neurodegeneration in experimental type 3 diabetes: relevance to Alzheimer's disease. J Alzheimers Dis. 2006 Sep;10(1):89-109. Review.
  • de la Monte SM, Wands JR. Alzheimer-associated neuronal thread protein mediated cell death is linked to impaired insulin signaling. J Alzheimers Dis. 2004 Jun;6(3):231-42. Review.
  • Dyer O. Is Alzheimer's really just type III diabetes? National Review of Medicine, 2005; 2(21).
  • Emerging Risk Factors Collaboration, Seshasai SR, Kaptoge S, Thompson A, Di Angelantonio E, Gao P, Sarwar N, Whincup PH, Mukamal KJ, Gillum RF, Holme I, Njølstad I, Fletcher A, Nilsson P, Lewington S, Collins R, Gudnason V, Thompson SG, Sattar N, Selvin E, Hu FB, Danesh J. Diabetes mellitus, fasting glucose, and risk of cause-specific death. N Engl J Med. 2011 Mar 3;364(9):829-41. doi: 10.1056/NEJMoa1008862. Erratum in: N Engl J Med. 2011 Mar 31;364(13):1281.
  • Fiorenza L, Benazzi S, Tausch J, Kullmer O, Bromage TG, Schrenk F Molar macrowear reveals Neanderthal eco-geographic dietary variation. PLoS One. 2011 Mar 18;6(3):e14769. doi: 10.1371/journal.pone.0014769.
  • Freude S, Schilbach K, Schubert M. The role of IGF-1 receptor and insulin receptor signaling for the pathogenesis of Alzheimer's disease: from model organisms to human disease. Curr Alzheimer Res. 2009 Jun;6(3):213-23. Review.
  • González-Reyes RE, Aliev G, Ávila-Rodrigues M, Barreto GE. Alterations in Glucose Metabolism on Cognition: A Possible Link Between Diabetes and Dementia. Curr Pharm Des. 2016;22(7):812-8. Review.
  • Hardy K, Radini A, Buckley S, Blasco R, Copeland L, Burjachs F, Girbal J, Yll R, Carbonell E, Bermúdez de Castro JM Diet and environment 1.2 million years ago revealed through analysis of dental calculus from Europe's oldest hominin at Sima del Elefante, Spain. Naturwissenschaften. 2017 Feb;104(1-2):2.
  • Henderson ST, Vogel JL, Barr LJ, Garvin F, Jones JJ, Costantini LC. Study of the ketogenic agent AC-1202 in mild to moderate Alzheimer's disease: a randomized, double-blind, placebo-controlled, multicenter trial. Nutr Metab (Lond). 2009 Aug 10;6:31. doi: 10.1186/1743-7075-6-31.
  • Henry AG, Brooks AS, Piperno DR Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium). Proc Natl Acad Sci U S A. 2011 Jan 11;108(2):486-91. doi: 10.1073/pnas.1016868108.
  • Henry AG, Brooks AS, Piperno DR Plant foods and the dietary ecology of Neanderthals and early modern humans. J Hum Evol. 2014 Apr;69:44-54. doi: 10.1016/j.jhevol.2013.12.014.
  • Krikorian R, Shidler MD, Dangelo K, Couch SC, Benoit SC, Clegg DJ Dietary ketosis enhances memory in mild cognitive impairment. Neurobiol Aging. 2012 Feb;33(2):425.e19-27. doi: 10.1016/j.neurobiolaging.2010.10.006.
  • LaManna JC, Salem N, Puchowicz M, Erokwu B, Koppaka S, Flask C, Lee Z Ketones suppress brain glucose consumption. Adv Exp Med Biol. 2009;645:301-6. doi: 10.1007/978-0-387-85998-9_45.
  • Messier C, Teutenberg K. The role of insulin, insulin growth factor, and insulin-degrading enzyme in brain aging and Alzheimer's disease. Neural Plast. 2005;12(4):311-28. Review.
  • Morris JK, Vidoni ED, Mahnken JD, Montgomery RN, Johnson DK, Thyfault JP, Burns JM. Cognitively impaired elderly exhibit insulin resistance and no memory improvement with infused insulin. Neurobiol Aging. 2016 Mar;39:19-24. doi: 10.1016/j.neurobiolaging.2015.11.005.
  • Müssig K. [Are high glucose levels a risk factor for dementia? High blood glucose levels increase the risk of dementia--not only in diabetes]. Dtsch Med Wochenschr. 2013 Oct;138(43):2184. doi: 10.1055/s-0032-1329063. German. No abstract available.
  • Ota M, Matsuo J, Ishida I, Hattori K, Teraishi T, Tonouchi H, Ashida K, Takahashi T, Kunugi H. Effect of a ketogenic meal on cognitive function in elderly adults: potential for cognitive enhancement. Psychopharmacology (Berl). 2016 Oct;233(21-22):3797-3802.
  • Richards MP, Pettitt PB, Trinkaus E, Smith FH, Paunović M, Karavanić I Neanderthal diet at Vindija and Neanderthal predation: the evidence from stable isotopes. Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7663-6.
  • Rosness TA, Engedal K, Bjertness E, Strand BH. Association Between Random Measured Glucose Levels in Middle and Old Age and Risk of Dementia-Related Death. J Am Geriatr Soc. 2016 Jan;64(1):156-61. doi: 10.1111/jgs.13870.
  • Steen E, Terry BM, Rivera EJ, Cannon JL, Neely TR, Tavares R, Xu XJ, Wands JR, de la Monte SM. Impaired insulin and insulin-like growth factor expression and signaling mechanisms in Alzheimer's disease--is this type 3 diabetes? J Alzheimers Dis. 2005 Feb;7(1):63-80.
  • Suzanne M. de la Monte, Jack R. Wands Alzheimer's Disease Is Type 3 Diabetes–Evidence Reviewed J Diabetes Sci Technol. 2008 Nov; 2(6): 1101–1113. Published online 2008 Nov. doi: 10.1177/193229680800200619
  • Walker JM, Harrison FE. Shared Neuropathological Characteristics of Obesity, Type 2 Diabetes and Alzheimer's Disease: Impacts on Cognitive Decline. Nutrients. 2015 Sep 1;7(9):7332-57. doi: 10.3390/nu7095341. Review.
  • Weyrich LS, Duchene S, Soubrier J, Arriola L, Llamas B, Breen J, Morris AG, Alt KW, Caramelli D, Dresely V, Farrell M, Farrer AG, Francken M, Gully N, Haak W, Hardy K, Harvati K, Held P, Holmes EC, Kaidonis J, Lalueza-Fox C, de la Rasilla M, Rosas A, Semal P, Soltysiak A, Townsend G, Usai D, Wahl J, Huson DH, Dobney K, Cooper A Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus. Nature. 2017 Mar 8. doi: 10.1038/nature21674. [Epub ahead of print]
  • Willette AA, Bendlin BB, Starks EJ, Birdsill AC, Johnson SC, Christian BT, Okonkwo OC, La Rue A, Hermann BP, Koscik RL, Jonaitis EM, Sager MA, Asthana S. Association of Insulin Resistance With Cerebral Glucose Uptake in Late Middle-Aged Adults at Risk for Alzheimer Disease. JAMA Neurol. 2015 Sep;72(9):1013-20. doi: 10.1001/jamaneurol.2015.0613. Erratum in: JAMA Neurol. 2015 Dec;72(12):1537.
  • Zhang Y, Kuang Y, Xu K, Harris D, Lee Z, LaManna J, Puchowicz MA Ketosis proportionately spares glucose utilization in brain. J Cereb Blood Flow Metab. 2013 Aug;33(8):1307-11. doi: 10.1038/jcbfm.2013.87

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