Could Alzheimer’s Begin in the Gut?

Alzheimer’s and dementia research has suggested a number of potential causes of memory loss, which remains one of the most devastating diseases of aging and affects nearly every family we know. One new link that seems particularly promising—both in terms of identifying ways to prevent and reverse memory loss—is the connection between the gut and the brain. Cardiologist turned autoimmunity/microbiome expert Dr. Steven Gundry—read more about his fascinating background here—reports that almost all of his patients who suffer from memory loss also have underlying gut issues. Here, Gundry explains how a problem in the gut may manifest as one in the brain, and shares the diet adjustments that he’s found most helpful for maintaining brain health, as well as for recovering memory loss post-diagnosis. (For more revolutionary diet tips from Gundry, put his forthcoming book, The Plant Paradox: The Hidden Dangers in “Healthy” Foods That Cause Disease and Weight Gain, on your list.)

A Q&A with Steven Gundry, M.D.


How much of memory loss is an inherent part of aging?


Memory loss doesn’t have to be a part of normal aging. While about 30 percent of people carry what is commonly called the “Alzheimer’s gene,” or APOE4, I’ve found that the wrong diet, a disorder of the gut microbiome, and/or leaky gut are the underlying causes of almost all memory loss cases that I treat—all factors that we’re actually able to address.


Do you have patients who have reversed or slowed down memory loss?


Yes, I have had the pleasure of witnessing patients reverse brain fog and memory loss after following The Plant Paradox program. Here’s one success story that I share in the book: An eighty-five-year-old man from Florida with moderate Alzheimer’s moved to Palm Springs with his wife so that his son could help care for them. The move had not gone well—disruptions often make dementia worse—and the man began wandering at night. A memory care unit was financially out of the question for the family.

I placed him on my Keto-Plant Paradox Intensive Care Program, restricting not only carbohydrates, but also animal proteins, so that 80 percent of his calories came from good fats like olive oil, avocados, coconut oil, and MCT oil. He stopped wandering; over the next six months, he began engaging the family in joking conversations. I saw him every few months along with his family, and checked his blood work frequently to see that he remained in ketosis (where the brain is burning fat for fuel).

About a year into the program, I walked into my exam room to find him waiting for me alone, without his son and wife.

“Where’s your family?” I asked.

“Home,” he replied.

“How’d you get here then?”

When he told me he drove himself, I must have had such a shocked look on my face, that he got out of his chair, put his hand on my shoulder, and said: “Doc, I’ve been coming here every few months for a year. Don’t you think that I would know the way by now?”


What are the early signs of Alzheimer’s/dementia and at what age do they present?


Interestingly, one of the earliest signs of Alzheimer’s/dementia is the loss or diminution of the sense of smell. The olfactory nerves directly connect to the brain from the back wall of the nose; they truly are a window into brain damage. If you can’t smell an open jar of peanut butter 10 inches from your face, you are in trouble. (Warning: Don’t do this test when you have a cold!) There is some research suggesting that some types of Alzheimer’s may be actually linked to inhaling toxins, like mycotoxins, i.e. mold.

Other typical signs include difficulty remembering things that recently or just happened, and an inability to plan, solve problems, or complete usual tasks. Many people lose track of dates or time. Many repeat the same stories to the same person. Some experience a change in mood or personality; become frivolous with money; display a lack of care about their appearance; and have a lack of interest in food, or a repeated craving for sweets or sugary/starchy foods.

I have seen these symptoms—often dismissed as “senior moments”—develop as early as age fifty, particularly with people who carry one or more copies of the APOE4 gene. Sadly, I have seen symptoms even earlier with vegans who have very low levels of the omega 3 fatty acid DHA in their blood. For those who follow a vegan diet, please note: Algae-based DHA supplements (as opposed to fish oil supplements) are now widely available and affordable. Humans cannot convert the omega 3’s in flax oil into long chain DHA’s, which our brain requires.


What do we know about potential causes?


The cause of Alzheimer’s is hotly debated and theories change about every three years, as drugs targeting the thought-to-be cause continue to fail. While you may read about amyloid plaque, Tau proteins, or how the tangles of both are the “cause” of Alzheimer’s, these are actually the visible signs that something is wrong with the neurons, not the cause of their demise.

Myself and others, like Dr. Dale Bredesen of the Bucks Institute of Aging, believe the underlying cause is a loss of mitochondrial flexibility—when the tiny energy-producing organelles in neurons (the mitochondria) lose the ability to generate energy from sugars or fats. Why does this happen?

Neurons (both in the brain and gut) are so important that they are protected by specialized white blood cells called glial cells, which act like bodyguards: If the glial cells detect a threat, they form a phalanx around the neurons to protect them. Unfortunately, they can do such a good job of keeping everything out that the neurons starve to death. This pathological condition is called a Lewy body, and can be diagnostic of Parkinson’s, for instance. Lewy bodies have been found in the wall of the intestines, as well as the brain.


Can you talk more about the gut connection?


The process described above stems from leaky gut, when particles—namely lectins, the proteins in plants—breach the gut wall. The Plant Paradox is all about how plants protect themselves from being eaten, in very sophisticated ways. This includes physical deterrents—for example, the spine-tipped leaves of artichokes, and the hard, outer coating of seeds. The major chemical defense system of plants are the proteins called lectins. Some lectins resemble proteins in the body, while others are designed to look like compounds that the body considers harmful, such as lipopolysaccharides (LPSs, or what I call, little pieces of sh*t)—which are fragments of bacteria that are constantly produced as bacteria divide and die in your gut. Lectins resemblance to other proteins in the body and LPSs can cause the immune system to attack, leading to inflammatory reactions in the body, and health issues like leaky gut, brain fog, neuropathy, and autoimmune disease.

To remove most troublesome lectins from the diet, avoid: gluten, grains, sprouted grains, beans, the nightshade family, cow milk (A1 casein acts like a lectin). Note: Although gluten is a kind of lectin, many gluten-free grains are full of other lectins.

In addition to our Western diet, we’ve also found that common antacids like Prilosec and Nexium, NSAIDS like Ibuprofen and Naproxen, are major causes of mitochondrial dysfunction. These antacids are called proton pump inhibitors (PPIs); they work by preventing stomach acid from being made. Until recently, we didn’t realize that they also block mitochondria from working, thereby killing nerve cells! Long-term use of these drugs may result in up to a 44 percent increased risk of dementia.
On the other hand, Dr. Bredesen’s work with the APOE4 gene suggests that plant compounds called polyphenols (like turmeric, and resveratrol, the compound in red wine) protect the brain and its mitochondria. How: These compounds affect the action of the sirtuin pathways that protect cells from damage at a genetic level; and they further enhance mitochondrial function by protecting against Reactive Oxygen Species (ROS) generation during energy production.


Can you talk a bit about the research linking high blood sugar to dementia/Alzheimer’s?


Proper mitochondrial function is essential to how the brain generates memory. Mitochondria can get overwhelmed by trying to turn sugar into energy 24 hours a day, 365 days a year. In the not too distant past, we did not have year-round fruit, year-round sugar, year-round unlimited access to calories, and the mitochondria got to have some time off. Now, overworked, overstressed, mitochondria are forced to slow down.

When mitochondrial energy production slows, the brain is unable to convert information into stored memory. Think of it this way: It’s like earning money, but having no checking account or savings account to store it in. When you go to retrieve your funds (remember something) your account is empty!


What can be done to prevent dementia and Alzheimer’s?


  • As mentioned above, sugar overwhelms mitochondrial function; it is toxic to nerves—so you want to avoid it. It’s no wonder that diabetics have neuropathy, but in most cases, this neuropathy can be partially or fully reversed via diet.

  • In general, limit animal fats, especially cow milk cheeses (which have lectin-like A1 casein). If you do have cheese, try to use goat, sheep, buffalo; or cheeses from France, Italy, or Switzerland, which are casein A2.

  • Use large amounts of olive oil. Studies from Spain suggest a liter per week (that’s twelve tablespoons a day!) improved memory over a five-year period compared to a low-fat diet.

  • Consume numerous polypenols: berries, chocolate, coffee beans, grape seed extract, pycnogenol, turmeric, and green tea extract.

  • Practice periodic fasting—when you allow your mitochondria to use your own fat stores for fuel: You can do this by fasting for 14-16 hours in a day, skipping a meal, or, in the winter, trying to eat just one meal a day periodically. This kind of fasting creates mitochondrial flexibility.

[If you have the APOE4 gene, you can see more of Dr. Gundry’s tips in this video, and even if you don’t, his health guidelines outlined in The Plant Paradox are beneficial to all.]


Why does dementia affect more women than men?


Women have twice the risk of dementia as men. Women’s immune systems have the ultimate in yin and yang duties. During pregnancy, the fetus is, in a sense, the greatest parasite—it must be tolerated by the female immune system, which must still be able to protect the woman from other invaders. Many believe that this contributes to immune system confusion. We also know that during labor and birth, the gut wall becomes permeable to bacteria and pieces of bacteria cell walls (LPS’s), and frequently incites an ongoing immune response to other organs, as well as nerves cells, in a self-attacking process called molecular mimicry. (I would bet that giving birth is a factor in the increased dementia risk that women face, but this hasn’t been thoroughly studied yet.)


Once you’ve been diagnosed with dementia or Alzheimer’s (or have begun showing symptoms), what can be done to slow/reverse the memory loss?


I’ve outlined a plan for people diagnosed with Alzheimer’s and dementia [see chapter 10 of The Plant Paradox: Eat a ketogenic diet, which means 80 percent of your calories come from good fats like olive oil, avocados, coconut oil, and MCT oil, and only 10 percent of calories come from carbs, and 10 percent from proteins. It is critical to have 16 hours between two of your meals (so between dinner and breakfast), and to have no calories for four hours before bed. The brain is cleaned of debris during sleep and if blood is diverted to the gut for digestion, the brain is deprived of this cleaning program. Start on neuron building supplements like lion’s mane (a type of mushroom available in capsule form) and bacopa extract, to name just two. Also, cold brewed coffee has an amazing brain-building compound. I’ve seen many success stories over the years—know that all is not lost, and in many cases the brain can be salvaged!

Dr. Gundry is the director of the International Heart & Lung Institute in Palm Springs, California, and the founder/director of the Center for Restorative Medicine in Palm Springs and Santa Barbara. He is the author of Dr. Gundry’s Diet Evolution: Turn Off the Genes That Are Killing You and Your Waistline and Drop the Weight for Good and the forthcoming The Plant Paradox: The Hidden Dangers in “Healthy” Foods That Cause Disease and Weight Gain.

The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of goop, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.

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