Busting popular misinformation about Alzheimer’s disease

IntroductioN

As the world’s population grows increasingly older, age-related medical conditions are expected to grow among healthcare concerns. One of the most devastating age-related illnesses is dementia, an umbrella term used to refer to several diseases that affect memory, thinking, and the ability to perform daily tasks. The most common form of dementia is Alzheimer’s disease, which could make up about 60 to 70% of all cases.

According to the World Health Organization, dementia is currently the seventh leading cause of death and a major cause of disability in the elderly worldwide. In Europe specifically, the number of people living with dementia is expected to nearly double by 2050, rising to more than 14 million in the European Union and more than 18 million in the wider European region. The impact of the disease is particularly marked in some countries: in the United Kingdom for instance, dementia is the number one cause of mortality.

These figures, coupled with the fact that dementia is one of the most feared age-related conditions, make the disease a popular subject of online discussion; there are more than 390,000 videos carrying the hashtag #alzheimer on TikTok, for instance.

But platforms for these discussions have also provided fertile ground for misinformation, as well as unproven supplements that some claim can prevent or cure Alzheimer’s. In this Insight article, we tackle some of the most common forms of misinformation about the causes and treatment of Alzheimer’s.

Popular myths about the cause of Alzheimer’s

Myth 1:

Reducing cholesterol in the diet or through statins can cause Alzheimer’s

Science Feedback has seen a few iterations of this claim, which we addressed in previous reviews (see here and here). These iterations broadly rely on a mix of inaccurate beliefs about Alzheimer’s disease and a misunderstanding of cholesterol biology in the brain.

As a building block for making hormones, vitamin D, and cell membranes, cholesterol is indispensable in the human body. It’s also a major component of the myelin sheath, a kind of insulating layer that coats neurons (nerve cells) and speeds up communication between neurons. Scientists have estimated that about 70 to 80% of cholesterol in the brain is present in the myelin sheath.

This might lead some to believe that consuming more cholesterol improves brain function. There’s just one problem: cholesterol is too large to pass through the blood-brain barrier. That means the cholesterol from our diet doesn’t directly influence cholesterol levels in the brain.

This biological fact is, however, glossed over by claims that encourage people to consume more cholesterol. Another crucial fact that’s left out is that our body is capable of making the cholesterol that it needs, using nutrients from our diet. In fact, about 80% of the cholesterol in our body is made by the liver. The brain, too, is capable of synthesizing its own cholesterol. And these processes are largely out of our control.

All of this is to say that trying to raise brain cholesterol levels by consuming a high-cholesterol diet is likely to be futile. Moreover, this approach is more likely to create the opposite effect.  Excess cholesterol builds up on the walls of arteries and ultimately obstructs blood flow, increasing the risk of cardiovascular disease. And cardiovascular risk factors, such as atherosclerosis and hypertension, contribute in multiple ways to increase the risk of Alzheimer’s disease^[1].

Statin drugs, which reduce cholesterol production in the body, have also been targeted by claims that they cause memory loss, but this belief is unsubstantiated by multiple large-scale studies, which didn’t find that statin use is associated with greater cognitive decline^[2-5].

In summary, social media posts claiming that reducing cholesterol in the diet or through statins leads to increased dementia risk are inaccurate. They oversimplify cholesterol biology and encourage behaviours that are more likely to result in harm than benefit.

Myth 2:

Alzheimer’s is type 3 diabetes

Among proponents of this myth is health influencer and chiropractor Gary Brecka, who has more than 1.2 million followers on TikTok, as shown by the videos here and here.

This myth potentially stems from the fact that insulin resistance is seen in type 2 diabetes and Alzheimer’s disease. The difference is that in type 2 diabetes, insulin resistance affects the peripheral tissues, while in Alzheimer’s, it affects the brain.

However, keep in mind that insulin resistance is a symptom of many different medical conditions, which include polycystic ovarian syndrome (PCOS) and fatty liver disease. Boiling all of these medical conditions down to diabetes simply because insulin resistance is a feature would therefore be a gross oversimplification.

Indeed, type 2 diabetes and Alzheimer’s are quite different diseases when we view them more holistically.

For example, Alzheimer’s disease happens when neurons in certain brain regions cease to work correctly and die off. This damage begins in the parts of the brain involved in forming and retrieving memories. Although most people with Alzheimer’s begin to show symptoms only when they are over the age of 65, published studies have shown that the molecular changes associated with the disease begin years or even decades before symptoms appear.

One of the hallmarks of Alzheimer’s disease is the build-up of two proteins called Tau and beta-amyloid in the brain. Scientific evidence suggests that this build-up is toxic for the brain and contributes to the neurodegeneration associated with Alzheimer’s disease^[6,7].

As the disease progresses, the parts of the brain that are involved in language, reasoning, and social behavior also become damaged. The brain shrinks as more and more neurons die. People with late-stage Alzheimer’s are no longer able to perform daily tasks on their own and become completely dependent on others.

Such neurodegeneration isn’t a feature of type 2 diabetes. On the contrary, type 2 diabetes is considered a chronic metabolic disorder caused by an impaired response to insulin, leading to high blood sugar.

Several epidemiological studies suggest an association between type 2 diabetes and a higher risk of developing Alzheimer’s disease^[8-10]. However, this doesn’t demonstrate a causal relationship between the two. On the contrary, the evidence suggests that the cardiovascular problems that increase the risk of type 2 diabetes are also implicated in dementia.

In summary, although type 2 diabetes and Alzheimer’s share insulin resistance as a common feature, they are still two very different diseases with symptoms that are distinct from each other.

Myth 3:

Alzheimer’s is caused by stress

This claim was shared by chiropractor Clint Steele in a TikTok video that has received more than two million views. Steele, who has more than two million followers on TikTok, uses the title of “Doctor” on TikTok without specifying that he holds a Doctor of Chiropractic instead of a medical degree (Doctor of Medicine). The disclaimer on his website, in fine print, specifies that “Dr. Clint Steele does not diagnose or treat any medical illness or condition”.

In the video, Steele claimed:

“Alzheimer’s dementia is due to stress on the brain. Physical stress, emotional stress, but also chemical stress. And so when you are putting more chemicals into your body via a prescription, via a medication, via something that is trying to alter functions in your body, it stresses out your brain. Your brain doesn’t know how to deal with it, and it stresses it out.”

This claim is not only unsubstantiated by evidence, it’s potentially harmful, since it encourages people to stop taking their prescribed medications to avoid this purported “stress” on the brain. The language of the claim also invokes chemophobia, the unfounded fear that chemicals—particularly manmade chemicals—are intrinsically harmful to people.

The scientific evidence currently doesn’t support Steele’s claim that Alzheimer’s disease is due to stress alone. This is not to say that stress doesn’t play a role, but the situation is far more complex than Steele’s claim lets on.

We reached out to UK-based charity Alzheimer’s Society regarding the scientific credibility of this claim. Richard Oakley, the Society’s Associate Director of Research and Innovation, told Science Feedback:

“Stress and its link with dementia is a complex subject as anxiety, depression, and lack of sleep are all associated with stress, but also with dementia risk. Evidence suggests chronic stress may play a role in dementia progression, but it doesn’t necessarily cause it.”

The Alzheimer’s Society has also published an article that addresses this claim in greater detail. It explains:

“There are many reasons why stress could be linked to dementia.

A key hormone released when you’re stressed, cortisol, has been linked to problems with memory. Stress is also closely linked to conditions such as depression and anxiety. These have also been suggested as factors that could increase the risk of dementia.  

Increased levels of cortisol in the body can effect brain regions such as the hippocampus, which is critical for memory. 

Stress also affects the immune system, which is known to play an important role in the development of dementia. Stress can lead to the release of chemical signals that trigger inflammation in the body and brain. Chronic inflammation in the brain can damage cells and affect how well brain cells communicate.”

Steele also alleged that only lifestyle can lead to dementia and that genetics “does not cause dementia”. There’s a grain of truth to that claim. Lifestyle factors do play a big role in influencing a person’s risk of developing Alzheimer’s. For example, professional athletes who often head the ball, like football players, have a higher risk of developing dementia, likely due to repeated brain trauma over a long period of time.

And then there are more mundane factors. Oakley told Science Feedback:

“We do have scientific evidence from The Lancet Commission, part funded by Alzheimer’s Society, that up to 45% of dementia cases worldwide could be prevented or delayed by addressing certain modifiable lifestyle risk factors. Some of these are down to individuals – such as exercising regularly, cutting back on alcohol, stopping smoking and correcting hearing or vision loss. Other risk factors require systemic change or environmental changes that aren’t within an individual’s control – such as addressing poor air quality.”

But genetics alone can and does explain some cases of Alzheimer’s. For one thing, familial Alzheimer’s disease is a form of inherited Alzheimer’s, albeit rare, that’s caused by mutations in certain key genes.

In summary, Steele’s claim oversimplifies the complexity of risk factors behind Alzheimer’s, leaving users with an incorrect understanding of the disease. More problematic is the encouragement to avoid prescribed medications, as untreated medical conditions are likely to lead to complications down the road.

Supplements to prevent or treat Alzheimer’s aren’t backed by evidence

Misinformation about Alzheimer’s isn’t limited only to its causes. Unsurprisingly, social media platforms have become an avenue for marketing supplements claimed to prevent or treat the condition. Science Feedback examined some of these claims in an earlier review and found them to be unsubstantiated by clinical evidence. Here we take a look at two supplements in particular.

Coconut oil

Consume coconut oil to prevent Alzheimer’s—that’s what videos (see here and here) by health influencer Robert Love and naturopath Barbara O’Neill are telling TikTok viewers. But the evidence for this claim is shaky, as we’ll see later on.

This claim may have its roots in the hypothesis that a ketogenic diet, which is a high-fat low-carbohydrate diet, mitigates energy dysfunction in the brain during Alzheimer’s disease.

Recall that earlier we mentioned how the brains of people with Alzheimer’s tend to exhibit insulin resistance. This is a problem for the brain, since its preferred energy source is glucose. If it has trouble taking up glucose, then it has trouble getting sufficient energy to maintain normal cell function. In fact, there’s some evidence suggesting this energy insufficiency contributes to the neurodegeneration seen in Alzheimer’s^[11].

However, cells are capable of using other sources of energy to mitigate energy insufficiency, and one such source is ketones. This is why scientists have begun to explore the potential benefits of a ketogenic diet in people with Alzheimer’s, as documented in this scientific review^[12].

Some groups of researchers pursuing this avenue of research have turned to experimenting with coconut oil supplementation. This is because coconut oil is rich in medium-chain triglycerides, which are readily converted to ketones by the liver.

While a few published studies have emerged, none demonstrate that coconut oil is effective at preventing or treating Alzheimer’s.

One study conducted in Spain was published in 2018 and looked at 44 people with Alzheimer’s disease^[13]. These people were randomly assigned to a control group and a treatment group that received coconut oil supplementation. The researchers reported that coconut oil supplementation “seems to improve cognitive functions” in people with Alzheimer’s.

However, this result comes with major caveats. For starters, it was quite small, with just 22 people in each group. Furthermore, the study compared effects before and after coconut oil supplementation using even smaller subgroups assigned based on a person’s sex and the severity of their symptoms.

This becomes evident when we look at the study’s Table 1, which shows the number of participants per subgroup; in the control group for males with mild-moderate Alzheimer’s symptoms, there was just one participant, while the treatment group for males with mild to moderate Alzheimer’s had just three participants. 

These sample sizes are extremely small and significant caution must be taken when interpreting comparisons between such groups, because they are prone to outliers. And they certainly cannot be used to generalize observations to a broader population.

A study conducted in Canada and published in 2022 was a randomized, double-blind, placebo-controlled trial in people with mild to moderate Alzheimer’s^[14]. One advantage of this study compared to others is its relatively long duration of 15 months. The study reported that 80% of participants showed “stabilization or improvement in cognition”. However, this study was quite small, with just 20 participants.

Another study published in 2023 was a randomized controlled trial conducted in Sri Lanka that looked at 120 people with mild to moderate Alzheimer’s disease^[15]. Unlike the previously mentioned studies, this study reported “no significant difference in cognitive scores” between the control group and the group that received coconut oil supplementation.

In short, the data that’s currently available is quite limited and doesn’t provide compelling evidence that coconut oil is effective for treating Alzheimer’s. Furthermore, the studies didn’t include people who don’t have Alzheimer’s, so they cannot show that coconut oil prevents Alzheimer’s in people who haven’t developed symptoms. More research, with larger and better-designed trials, is needed.
Apart from the lack of evidence for efficacy, coconut oil is high in saturated fat. Excessive consumption of saturated fat increases the risk of cardiovascular conditions, which as we explained earlier, raises the risk of Alzheimer’s. The bottom line is that, far from helping, coconut oil supplementation could have the opposite effect.

Lion’s mane mushroom (Hericium erinaceus)

Lion’s mane is an edible mushroom that’s also used in traditional Chinese medicine. In several TikTok videos, health influencer Robert Love touted lion’s mane mushroom supplements for preventing Alzheimer’s. Love, who has more than 2.9 million followers on TikTok, incidentally has an online shop selling a lion’s mane-containing supplement.

Like Steele, Love uses the title of “Doctor”, but it’s unclear what qualification this title is based on. He has described himself as a neuroscientist; a previous Science Feedback review found that Love doesn’t hold credentials in neuroscience, but in a different field called cognitive psychology.

Love’s website cited one study to demonstrate the benefits of lion’s mane in Alzheimer’s^[16]. On closer reading, we can see that this trial was very small, with just 41 participants who completed it. This group was further divided into a control group and treatment group, with roughly 20 people in each. This greatly limits how much we can generalize the results.

Moreover, the people who were included in the study were already diagnosed with mild Alzheimer’s disease, meaning that the study doesn’t tell us whether lion’s mane prevents people from developing Alzheimer’s in the first place. None of these caveats about the study are mentioned on Love’s website.

This is not to say that lion’s mane is irrelevant to research about potential treatments for Alzheimer’s, but we’re still a long way from making it clinically effective. One study found that a certain extract of lion’s mane, called hericene A, could stimulate the growth of connections between neurons growing in the laboratory^[17]. It also found that mice fed with hericene A showed improved memory.

While these results are promising, it’s still uncertain whether these effects will also occur in human beings. The study’s authors also noted that there remain several barriers to using compounds like hericene A as a real-world therapy, citing “poor oral bioavailability”, “very low stability in serum”, as well as “minimal” ability to pass through the blood-brain barrier. They also postulated that such compounds could produce undesirable side effects like pain and even neurodegeneration, indicating that caution is warranted.

The bottom line: much more work still needs to be done before hericene A or other lion’s mane extracts live up to their clinical potential.

“Contrary to some viral online videos, there is very little evidence to suggest that Lion’s Mane mushrooms or coconut oil could be used as a treatment or cure for Alzheimer’s disease,” Oakley told Science Feedback.

Conclusion

Research into the causes of Alzheimer’s, as well as its treatment continues to improve our understanding of the disease and how it might be tackled. But the disease is complex. While reaching for simplistic solutions promoted by health influencers can feel appealing, the scientific evidence to back these claims up is scant.

Oakley said:

“One in three people born today in the UK will develop dementia in their lifetime and it’s the number one killer in the UK. It’s therefore no surprise that its causes, treatments and potential for prevention garner significant attention in the media and on social media. Social media is a powerful tool for sharing health information but it’s crucial that people take caution and speak to a health professional before changing medical treatments or adopting a lifestyle change that they’ve seen recommended online.”

READ MORE

Alzheimer’s Society UK published an article addressing misinformation about dementia, which can be found here.

REFERENCES

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