Brain Health: Can the Keto Diet Help With Alzheimer’s Disease?

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Can you eat your way to brain health? Exciting news is afoot when it comes to your eating habits and cognitive (brain or mental) functions. Researchers are looking into how the keto diet supports brain health and eases and slows down Alzheimer’s disease symptoms. So far, the results are promising. 

In this article we’ll explore:

  • What the keto diet is
  • How it might help with Alzheimer’s disease
  • What keto foods are good for brain health

What Is the Keto Diet?

The ketogenic diet is a high-fat, moderate-protein, low-carbohydrate (carb) eating plan. The eating approach was first prescribed for people with a brain disorder that causes seizures called epilepsy.

The blood-brain barrier provides a structural and functional roadblock against harmful microbes (e.g., bacteria, viruses, fungi and parasites) and toxins that circulate in your bloodstream and cause illness and disease.

Your liver makes chemicals called ketones when sugars in your blood called glucose are in short supply. Ketones can cross the blood-brain barrier to help prevent seizures. 

More recently, keto has been used to manage other health conditions such as Alzheimer’s disease, autism spectrum disorder and obesity.

Keto allows for:

  • 60% to 70% fat
  • 20% to 30% protein
  • 10% carbs 

For most people, this means having around 20 to 50 grams of carbs per day. The benefits of keto may include:

  • Higher metabolism
  • Less heart disease risk
  • Lower blood pressure
  • More lean muscle mass and less fat mass
  • Reduced hunger
  • Weight loss

Research to Support the Keto Diet for Cognitive Health

Researchers have found the keto diet may improve brain health, too. Your brain requires a constant source of energy to function well. When you eat [and drink] a lot of carbs, your brain gets its fuel from glucose in your blood. 

When you limit carbs, glucose becomes scarce in your blood. Your brain adapts to using ketones as fuel instead of glucose. 

How Ketones and Ketosis Work

Your liver makes ketones when it breaks down fats. These ketones then make their way back into your bloodstream. 

Eventually, your muscles and other body tissues pick them up to fuel metabolism. To reach ketosis, the concentration of ketones in your blood hovers around 0.5 to 3 millimoles per liter.

Keto helps propel your body into a state of ketosis. Keep in mind that you may need to eat in this manner for at least a few days to enter this state.

Being in ketosis means your body is mainly breaking down fat for energy. After being in ketosis for a while, proponents of the keto diet say you become “fat-adapted.”

This means your body now effectively burns fat as its main energy source. This can take around 4 to 12 weeks, depending on how strictly you follow the keto diet. 

Some people become fat-adapted earlier than most. This often includes endurance athletes who tend to burn through all energy sources much more quickly.

Ketones and Your Brain

Research has shown switching to ketones for brain fuel may benefit brain health. Cognitive enhancements have been seen in younger and older adults without dementia.

These include improved learning and memory. But due to its ill effects on brain functions, achieving and maintaining ketosis may be especially helpful for people living with dementia symptoms. 

Ketosis boosts the level of beta-hydroxybutyrate, the main and most stable type of ketone in your blood. This allows the brain to metabolize more fats to fuel its many functions. 

Keto Diet and Alzheimer’s Disease Symptoms

Like other types of dementia and brain disorders, research has shown keto may boost brain health in people with Alzheimer’s disease.

What Is Alzheimer’s Disease?

Alzheimer’s disease is the most common type of dementia. This brain condition greatly impairs your cognitive abilities. You slowly lose all mental functions as your Alzheimer’s disease symptoms grow worse. 

What Research Says About Keto’s Effects on Alzheimer’s

Several study reviews have found the keto diet improves brain health in people with Alzheimer’s. This is especially true when ketone levels are high enough to trigger ketosis. 

Some experts also propose that keto helps ease disease symptoms by boosting levels of chemical messengers in your brain called neurotransmitters, including norepinephrine and gamma-aminobutyric acid. It may also decrease deposits of abnormal proteins in the brain tied to dementia and Alzheimer’s called beta-amyloid (βA) and tau.

Researchers note ketosis may impede inflammation within your body and brain, which can slow down the debilitating progress of the disease. People often lose weight on keto, which can also curb inflammation.

It may also reduce oxidative stress, which is an imbalance between antioxidants that protect your body and brain and the free radicals that damage them. This form of stress harms many of the fat molecules that make up much of your brain cells, killing or inflaming these cells.

Type 2 diabetes, high glucose levels and insulin resistance increase inflammation and oxidative stress. Insulin resistance happens when cells in your muscles, fat and liver don’t respond well to a hormone made by your pancreas called insulin. This makes it harder for your body to break down and use glucose for energy.

Diabetes can heighten your risk for Alzheimer’s. This is because high fasting blood and brain glucose levels may alter the way your brain processes and clears βA.

A pocket of your large intestine called your cecum houses many of your body’s trillions of microbes. This is called your gut microbiome. 

Your gut microbiome may play a role in the development and progression of Alzheimer’s disease. Microbes that live here influence behavior and brain functions through the actions of gut neurotransmitters that behave in similar ways to the ones in your central nervous system (CNS).

These include:

  • Dopamine
  • Gamma-aminobutyric acid
  • Norepinephrine

This 2-way communication channel between your CNS and gut is called the brain-gut axis. Total calories and various nutrients can alter the composition of microbes in your gut for better or worse. These include carbs, fats, proteins and vitamins.

People with Alzheimer’s disease may have a higher ratio of harmful bacteria in their gut microbiome called Proteobacteria. These microbes can cause inflammation and diseases such as colorectal cancer and inflammatory bowel disease.

Is the Keto Diet Safe for People With Alzheimer’s?

Keto foods high in saturated fats can raise the risk of heart disease and other conditions associated with dementia and Alzheimer’s, such as:

Low-carb diets such as keto can suppress hunger and appetite. Along with swallowing and eating in general, these are issues that people with Alzheimer’s struggle with as the disease advances. 

Skipping meals can lead to calorie and nutrient deficiencies. This can make Alzheimer’s worse.

Keto can also raise the risk of digestive issues such as constipation, diarrhea or vomiting along with other health problems such as:

  • Anemia
  • Imbalance in body minerals called electrolytes (e.g., low levels of magnesium and sodium)
  • High uric acid levels, which are associated with conditions such as gout and kidney disease
  • Kidney stones
  • Vitamin deficiencies (e.g., vitamins A, C and K)

Brain Healthy Foods on the Keto Diet

Curious to know what to eat on the keto diet? Many foods can be included with this approach. But like other eating plans that support brain health such as the MIND diet, it’s still best to focus on whole foods and limit or avoid refined and processed foods.

Healthy Fats for Keto

Eat more healthy fats such as:

  • Butter (grass-fed, organic or raw)
  • Dark cacao nibs (unsweetened, unprocessed bits of raw chocolate)
  • Extra-virgin avocado, coconut and olive oil (unrefined, cold-pressed) 
  • Heavy cream

Limit safflower, sunflower and corn oils.

Proteins for Keto

Eat moderate amounts of meats, poultry, seafood and dairy products such as organic, grass-fed, hormone-free and cage-free:

  • Beef 
  • Eggs
  • Cheese
  • Chicken
  • Fatty fish like salmon
  • Tempeh and tofu

Eat less proteins high in saturated fats such as bacon.

Keto Nuts and Seeds 

Focus on nuts and seeds such as:

  • Almonds
  • Chia seeds
  • Flaxseeds
  • Hemp hearts
  • Walnuts

On occasion, enjoy:

  • Almond butter (unsweetened)
  • Cashews
  • Peanuts and peanut butter (unsweetened)
  • Pistachios

Keto Fruits and Vegetables

Include keto fruits such as:

  • Avocados
  • Blueberries
  • Kiwi
  • Raspberries
  • Rhubarb
  • Strawberries
  • Watermelon 

And keto vegetables such as:

  • Celery
  • Leafy greens such as kale, spinach and arugula
  • Mushrooms
  • Tomatoes
  • Zucchini

How to Start the Keto Diet Safely

Keto is not recommended for people who have or have had an eating disorder, as well as those with conditions that affect their:

  • Gallbladder
  • Liver
  • Pancreas
  • Thyroid

Below are some steps to help you get started on keto safely. Share these tips with your doctor and registered dietitian nutritionist. Be sure to get their buy-in before you try them or add them to your therapeutic care plan.

  • Drink plenty of low- or no-carb healthy fluids such as water or bone broth. You may lose extra body fluids while in ketosis.
  • Add 1 to 2 grams of salt to your diet each day. You may lose more sodium in your urine since you’re eating fewer carbs.
  • Eat plenty of potassium- and magnesium-rich foods to help prevent muscle cramps. Check with your doctor before getting these nutrients through supplements.
  • Avoid intense exercise for at least a week after starting keto. It’s best to work out at a light to moderate pace until your body and energy levels have adapted to this eating approach.