Livraison gratuite : France 70€, Belgique 100€, Reste de l'Europe 120€, DOM 220€

Glucose vs ketones: What is the best source of energy for your brain?

Glucose, low-carb diet and energy

In order to function, the brain uses glucose as the main source of energy. But what happens when you switch to a low-carbohydrate ketogenic diet?

Ketones, kézako?

Before we immerse ourselves in the definition of ketones in relation to the ketogenic diet, let us talk about our Western regime. This diet is loaded with foods rich in sugar. Is it not that sugar gives a better taste to food? If you eat a whole lot of sugar and exceed your glycogen storage capacity, your body converts it and stores it as a fat. And you take weight.

Sugar is not bad for health. In fact, the brain prefers sugar as the main fuel and consumes about 120 grams per day.

However, during periods of starvation, prolonged fasting, or when a person follows a ketogenic diet for the first time, liver glycogen is depleted. In this case, the mitochondria of your liver cells produce ketones from essential fatty acids or stored fat from your body. This process is called ketogenesis.

Ketones are considered to be an alternative fuel for the brain and other vital tissues of your body (such as your heart and skeletal muscles) when glucose is missing.

There are three types of ketones:

1. Acetacetate
Acetoacetate is the first ketone body produced by your liver. Acetoacetate is reduced to beta-hydroxybutyrate, which is another type of ketone. Immediately after the birth of a child, the newborn prefers acetoacetate and beta-hydroxybutyrate to glucose for brain growth.

2. Beta-hydroxybutyrate
Beta-hydroxybutyrate (BHB), which is composed of acetoacetate, is considered to be an efficient energy vector. It is more energy efficient than glucose. It is also the most abundant circulating ketone body.

3. Acetone
Acetone is the least abundant type of ketone body. It represents 2 % of ketones in your bloodstream. It is a result of degradation of acetoacetate and is found in the breath.

What is glucose?

Glucose is the main sugar in your blood. The carbohydrates of the foods you eat are converted to glucose.

Glucose is essential: it provides your organs with an energy that they can immediately use. It allows you to perform intense training, acts as a raw material so that your body can produce other molecules (for example, collagen) and serves as a fuel in the brain.

Glucose also takes other names-dextrose, starch, or glycogen:

1. Dextrose
Dextrose is a simple sugar that comes from corn or other plants. It is commonly found in foods such as honey, packaged products, desserts and corn syrup. In hospitals or medical facilities, dextrose is used as an intravenous drug.

2. Amidon
Starch is a complex type of carbohydrate because it consists of large units of glucose that are joined by glycosylic bonds. We often consume starch by eating staple foods such as rice, white flour, oats, pasta, corn, potatoes and bread products.

3. Glycogene
Glycogen acts as the main form of glucose storage. Every time your body needs energy, glycogen breaks down into glucose. Your liver releases glycogen in response to stressful situations, low blood sugar levels, and easier digestion.

As you can see, glucose plays several roles. But what are the reasons for using ketones as an alternative to glucose when it is clear that glucose is essential for many body functions? We respond to this in the following sections.

Can the brain draw energy from the ketones?

Yes! While we recognize glucose as the main source of energy in the brain, surprisingly, the brain also uses ketones, mainly beta-hydroxybutyrate and acetoacetate as an extra fuel.

In fact, during sleep, you enter a state of fasting that allows your body to draw on its glycogen reserves. When glycogen stores are low, your body metabolizes your stored fat that is converted to fatty acids. The fatty acids then decompose to ketones.

A study has shown that the increase in your ketone rate thanks to a very high fat and carbohydrate ketogenic diet can be beneficial for patients with brain diseases such as Alzheimer's and epilepsy.

Cetones vs glucose: what is the best fuel for your brain?

Advantages of ketones

1. Ketones improve mental performance

The brain is considered the most fat organ in your body-it contains almost 60 % fat. Having said that, it makes sense to provide your brain with fatty acids so that it can perform its functions. Since your body cannot produce fatty acids on its own, you must get them from your diet. Essential fatty acids include omega-3 fatty acids and omega-6 fatty acids.

A well-planned ketogenic diet includes healthy fatty acids such as avocados, olive oil, nuts and seeds, and fatty fish.

2. Ketones can benefit patients with head trauma

Cranial trauma or traumatic brain injury is caused by a severe blow to the head that damages the brain tissue. Trauma is due to falls, vehicle accidents, sports injuries. Whatever the cause, head trauma leads to anxiety, depression, loss of coordination, coma and convulsions.

While the injured brain needs energy to recover, it cannot efficiently metabolize glucose. Many clinical reports show that glucose metabolism is depressed after trauma. The use of a ketogenic diet on these patients offers alternative fuel to the brain as ketones.

Disadvantages of ketones

1. You feel side effects when adapting kéto

When your body adapts to a kéto diet, you collectively experience symptoms known as the keto flu. These symptoms include headaches, dizziness, concentration difficulties, dizziness and nausea. They happen when your brain goes to the ketones as the main source of energy.


The Benefits of Glucose

1. Glucose helps you perform difficult mental tasks

Your brain consumes 10.8 calories in just one hour to complete its tasks. The more difficult the mental task, the more glucose it takes. Scientists suggest that consumption of sweetened foods should improve the performance of these tasks.

2. Glucose improves child care time

Based on conventional knowledge, we can say that glucose helps us to refocus when we feel exhausted. For example, during a break between exams, taking a sweet drink brings us back into action.

A study examined 60 children aged six and seven years. At the end of the school day, they were given a drink. This drink contained 25 grams of glucose or a placebo. The results showed that those who had the glucose-filled beverage could keep their attention longer.


1. Usual consumption of sugar may increase the risk of depression

Too much sugar, especially sugar in soft drinks, juices and pastries, reduces your brain-derived neurotrophic factor.

2. Sugar triggers the brain reward centers of addiction

A 2018 research has explored the influence of sugar on obesity, a disease that affects millions of people around the world. It is no secret that sugar is found in the highly processed foods we eat. But how does sugar contribute to obesity?

Sugar is addictive because it stimulates the reward circuit of your brain related to addiction.


While the brain functions via glucose, it uses ketones as an alternative whenever there is a shortage of glucose. If you wonder whether the transition from glucose to ketones as cerebral fuel is worth it, consider the points discussed above.

Glucose is essential and that is certainly true. However, too much glucose in the blood does more harm than good. Sugar is associated with health problems such as depression and obesity.

If you are planning to start a ketogenic diet for brain health, be sure to consult your doctor first.

Older Post
Newer Post
Close (esc)
Rejoignez la communauté Keto !

Inscrivez-vous à notre newsletter pour être informé des nouveautés et recevoir nos offres promotionnelles ! 

Et bénéficiez d'un coupon de réduction de 10% sur tout le site pour votre première commande !

Age verification

By clicking enter you are verifying that you are old enough to consume alcohol.

Shopping Cart
Your cart is currently empty.
Shop now