Breaking Up With Sugar, to Avoid Alzheimer’s

When love hurts, give it up.

Sugar and the brain have a strange relationship, one that could be described as co-dependent. You may love sugar, and use it to fuel your brain, but it doesn’t love you back. Instead, it will slowly chip away at your cognitive faculties, causing damage that can eventually lead to Alzheimer’s disease. Perhaps it’s time to consider ending this destructive relationship.

A study published in October 2021 found that when the brain begins to degenerate, at the pre-dementia stage, it starts taking up sugar in large amounts. Why precisely this happens is not clear. But it may have something to do with brain insulin resistance.

Which has a lot to do with sugar.

You are probably already aware that regular consumption of sugary foods and drinks puts you at risk of developing type 2 diabetes. But before that happens, there is usually a pre-diabetic stage called insulin resistance. Insulin is the hormone released by the pancreas to maintain even blood glucose, and insulin resistance arises when this hormone starts to lose its effectiveness and the body no longer responds as it should. Consequently, blood sugar levels remain high, instead of being properly processed.

Something very similar happens in the brain. Brain insulin resistance is linked to memory problems and cognitive decline, as seen at the pre-dementia stage. If it isn’t addressed, it can progress to neurodegeneration and eventually to Alzheimer’s disease.

Insulin resistance is a feature of Alzheimer’s, the sixth leading cause of death in the United States and one with no cure or effective treatment. Its running mate is diabetes, the seventh leading cause of death. Alzheimer’s was first referred to as “type 3 diabetes” by researchers writing in the Journal of Alzheimer’s Disease in 2005, because of the strong relationship between the two diseases.

Over 80% of people with Alzheimer’s disease have either type 2 diabetes or abnormal blood sugar levels.

“T2DM (type 2 diabetes) has long been shown to be associated with dementia”

Alzheimer’s is characterised by several factors, including the build-up of β-amyloid (Aβ) plaques and neurofibrillary tangles. This is attributed to “impaired insulin signaling”.

The increased exposure to glucose makes the brain susceptible to a process called glycation. In glycation, certain proteins become damaged by glucose, creating substances called advanced glycation end-products (AGEs).

These AGEs can prevent neurons from working properly. Research has found that the brains of people with Alzheimer’s have high levels of these AGEs, compared to others without the disease.

Wait a moment. Doesn’t the brain need glucose?

Perhaps you’ve noticed a strange anomaly here. After all, the brain burns glucose for fuel, and the brain needs a lot of fuel. It may only occupy around 2% of the body by weight, but it burns 20%-25% of available energy. How can something so good be so bad?

Dietary carbohydrates are metabolised in the gut to glucose. That glucose then enters the blood. But that doesn’t make glucose essential: if you eliminate or greatly reduce your carbohydrate intake, your body will switch to burning fat instead. On a low carbohydrate diet, you move from burning glucose to burning fatty acids, and some of those fatty acids are converted in the liver into substances called ketones that provide fuel for the brain.

The brain switches to burning ketones when glucose is in short supply and the liver can produce enough ketones, per day, to meet the brain’s requirements. Dementia is not an obstacle to ketone production — ketone uptake remains entirely normal in people with Alzheimer’s or with mild cognitive impairment, the pre-dementia stage.

‘In contrast to glucose, brain uptake of ketones appears to still be normal in AD. Hence, ketogenic interventions may help delay AD.’ (Cunnane et al 2016)

Eating a low carbohydrate diet is essential to produce ketones. In a study where elderly people with mild cognitive impairment were given either a high carbohydrate or very low carbohydrate diet for six weeks, researchers observed improved verbal memory performance in the low carbohydrate subjects only.

This group also experienced reductions in weight, waist circumference, fasting glucose and fasting insulin levels. They produced ketones, and the level of ketones produced was positively correlated with memory performance.

Thus, even within a short period of time, low carbohydrate intake can improve memory function in adults at risk of developing Alzheimer’s.

“These findings indicate that very low carbohydrate consumption, even in the short-term, can improve memory function in older adults with increased risk for Alzheimer’s disease.”

It is rare today for most people to arrive at the point where they are producing ketones in the absence of glucose. On the contrary: high glucose is the norm for so many people consuming vast quantities of sugary and starchy carbohydrates, and then snacking on carbohydrates. Thus, the brain burns glucose all the time, leaving it vulnerable to brain insulin resistance — and ultimately dementia.

It is said that glucose is the brain’s “preferred” fuel. But when ketones are present in the blood, they are used preferentially by the brain over glucose.

“…if the energy needs of the brain are being increasingly met by ketones, glucose uptake decreases accordingly. This decrease in brain glucose uptake when both ketones and glucose are available supports the notion that ketones are the brain’s preferred fuel.” (Cunnane et al 2016).

Ketones can be created not just from fat in the body but also from certain fats in the diet. Some saturated fats — the medium-chain triglycerides (MCTs) — are easily converted into ketones. For that reason, scientists believe that these MCTs may be beneficial to people who have Alzheimer’s or some form of memory impairment. If they can’t use glucose, they can use MCTs instead.

MCTs are found in dairy foods and coconut. The coconut is an especially rich source. In fact, it has been singled out as a “potential cognitive strengthener” for people with Alzheimer’s. Raw coconut oil is an excellent cooking medium and can be used for frying, as an alternative to refined, vegetable cooking oils.

How to make your own glucose

Carbohydrates are, essentially, non-essential. They provide glucose, and indeed some cells are entirely glucose dependent. Those cells are erythrocytes (red blood cells), and the tissues of the cornea, lens, retina, testis, and the medulla of the kidney. However, In the absence of carbohydrate, the body manufactures glucose from protein and fat, in a process called gluconeogenesis.

Note that the brain is not a part of the body that is glucose-dependent.

Give it up for ketones

Human dietary requirements are surprisingly simple.

No one needs sugar. No one needs cookies, cakes, candies, chips and soda. Your body just needs real, wholesome food. You need plenty of protein — meat, fish, eggs, cheese — and plenty of vegetables to go with that protein.

Something else you can do is avoid snacking between meals. Apart from being superfluous to dietary requirements, snacking means that insulin production is constantly stimulated. By abstaining from snacking, you give your pancreas a rest, and your body the chance to start burning fat and ketones for fuel.

Which is something that is urgently needed, with the ever-rising prevalence of diabetes, expected to reach 10%–20% of the global population by 2030. Cases of Alzheimer’s are expected to triple by 2050.

With that in mind, it is surely time to develop a healthier relationship with food and break the cycle of dependency. Parting is not such sweet sorrow, after all.

Insulin sensitivity can also lead to depression and anxiety. For further information on this link, see my article below:

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