Can avoidance of refined sugar help you protect your brain and support the prevention of Alzheimer’s dementia?

By Hamid R. Sagha, M.D. | April 21, 2020


What is refined sugar, and what do we need to know about it?

The term refined sugar refers to sugar removed from its natural sources.  It’s then purified and then turned into a form that we can add to other foods.  Another name often used for refined sugar is added sugar. You need to know that it does nothing good for you (except provide a momentary delightful taste).  In fact, it does great harm to your health and your cognitive abilities.

How to identify foods that contain refined sugar

In July 2018, the Federal Food and Drug Administration began requiring that most packaged food suppliers add this term to their food labels.  As such, it’s easier for consumers to know the amount of refined sugar each product contains.

Sources for refined sugars include cane sugar, sugar beets, and corn.  Manufacturers process these sugars into granulated sugar, powdered sugar, high fructose corn syrup, and brown sugar.  They also process these sugars into molasses, coconut palm sugar, agave, or any other food they can dream up.

No matter what you call these refined sugars – they are all terrible for you!  Once removed from their natural sources, they have little nutritional value.  Refined sugars can promote your feelings of fatigue.

Why is refined sugar bad for your brain?

Many processed foods contain refined sugar.  The list includes breakfast cereals, pasta sauce, ketchup, baked beans, sweetened yogurt, soups, bread, barbecue sauce, fruit drinks, instant oatmeal, and salad dressing.  Also, on the list are breakfast bars, beer, frozen entrees, and sweetened dried fruits like cranberries.  Obviously, the same list includes bakery products like cake, cookies, and donuts.

Naturally occurring sugars come packaged in fruits, vegetables, milk, and other foods with fiber, vitamins, antioxidants, and other healthy nutrients.  All these extras—especially the fiber in fruits and vegetables—slow the absorption of sugar into the blood, protecting you from sugar spikes. Think less fiber, more damage from sugar.

In the absence of fiber, your body converts refined sugar into glucose very quickly.  The sudden infusion of glucose into your bloodstream causes your blood sugar to rise suddenly.  As a result, your body experiences a sugar spike. Your body adjusts to these changes if you have optimal metabolic health.

Unfortunately, this is not true for your brain.  The brain needs a steady source of glucose to function correctly.  So, any sudden and extreme infusion of sugar is dangerous (for both diabetics and nondiabetics).  The brain reacts to sugar spikes as if they were a virus or bacteria—with an immune response that can lead to chronic inflammation.

Scientists offer four reasons for this quick and often destructive response to sugar spikes.

1.  Glycation

  • Glycation occurs when your body does not take of care the sugar that enters your system. The excessive sugar bonds with proteins, creating toxic compounds called advanced glycation end productsor AGEs.  These AGEs keep the proteins from doing their work.  If sustained, glycation leads to vascular tightening throughout the body, cataracts, wrinkled skin, and other problems. (Yes, too much sugar causes you to look older.)
  • When glycation occurs in the brain, stiffened blood vessels impede blood flow to and around the brain, depriving the brain of energy. Patrick Holford is a leading nutritionist specializing in mental health. He says, “The more the arteries become damaged, the worse the circulation to the brain and the less reliable the supply of nutrients becomes.  So, ironically, overeating sugar can lead to temporary glucose starvation to cells, as well as damage caused by excess glycation.”
  • The brain sees glycation-damaged proteins as a threat, so microglia rush to where they are, causing neuroinflammation. Short-term, the microglia can deal with the perceived danger, but if you repeatedly cause sugar spikes—whether or not you have diabetes—the neuroinflammation becomes chronic, and your brain
  • Glycation releases 50 times more free radicals than other proteins do. Subsequently, the release results in more oxidation, and as we know, oxidation adds to the neuroinflammation.

2.  Macrophage migration inhibitory factor (MIF)

  • Sugar spikes in the brain also damage an enzyme called the macrophage migration inhibitory factor(MIF).
  • Undamaged MIF helps the immune response to produce abnormal proteins in the brain.
  • When sugar damages the MIF, the immune process kicks in again, making inflammation more likely, and increases your risk of Alzheimer’s.

3.  Impaired BDNF

  • Research indicates that if your diet is high in refined sugar, it reduces the production of a chemical in the brain that’s known as a brain-derived neurotrophic factor(BDNF).  If your production of BDNF is inadequate, your brain cannot form new memories, thus inhibiting your ability to learn.
  • Sugar spikes are the enemy of brain-derived neurotrophic factor (BDNF), which is crucial in the fight against Alzheimer’s dementia.
  • Spikes from refined sugar lower your brain’s production of BDNF, with disastrous results for your brain cells.
  • The healthy production of BDNF is vital because the process:
        • Protects your ability to form new memories and to learn and remember;
        • Stimulates the development of neurons and strengthens existing ones;
        • Protects against the damage that stress does to your brain cells; and
        • Helps your neural pathways—the communication highway for your brain—to stay supple and active.

4.  Increased free radicals in the brain

  • Excess sugar in the brain also contributes to increased free radicals, which cause oxidative damage that occurs with each new sugar spike. Since your body correctly perceives this process as a threat, it sends microglia to fight the process.
  • If sugar spikes continue throughout your day, the microglia cannot keep up with the process and chronic neuroinflammation results. 

A necessary step for a healthier brain

We still have more to learn concerning the effect of sugar spikes on the brain.  However, for now, if you want to keep your brain healthy, limiting your intake of refined sugar is a crucial step.

The average American consumes about 3 pounds of refined sugar a week, or 156 pounds per year.  This fact isn’t surprising when you consider it’s in so many foods.

Imagine, refined sugar accounts for about 500 calories each day in the average American diet. What’s more, a third of those calories come from regular soft drinks.  Yet, nothing healthy comes from all this refined sugar, not in your body, and certainly not in your brain.

Refined sugar should not be part of your regular diet.  You should reserve it for special occasions—enjoying it as a rare indulgence.

The time to take action is now

Specific details about how to reduce the amount of refined sugar in your diet are available in my book, Dementia Action Plan: Give Your Brain a Fighting Chance.  Additionally, our website provides information on how to do a pantry intervention.  The guidelines offered will help you rid your home of foods containing refined sugar and other additives detrimental to your health.

If you make an effort to avoid consuming refined sugar, you will have a better chance of maintaining a healthy brain.  A healthier brain supports the preservation of your memories and your ability to keep learning.  The brain can also better protect itself from the causes of cognitive decline and lower your risk of Alzheimer’s dementia.

The evidence is indisputable.  A failure to take action is not an option.  Start avoiding refined sugar today.