What Is Type 3 Diabetes? Insulin Resistance In The Brain That Could Trigger Alzheimer’s
Most people are aware of type 1 and type 2 diabetes, but did you know there is a type 3 diabetes as well! It is a more obscure term. Although it is not an accepted medical diagnosis, type 3 diabetes has been discussed in the literature as a possible relationship between insulin resistance in the brain and Alzheimer's disease. This link has been described to help explain how metabolic disorders impact brain health, causing cognitive decline and dementia.
Type 3 diabetes is more of a misnomer because it should not be confused with type 3c diabetes, which relates to pancreatic dysfunction. The term "type 3 diabetes," on the other hand, has been loosely used by some scientists to analogously propose that Alzheimer's disease is strongly implicated with insulin resistance in the brain.
This concept was conceptualized by Dr. Suzanne de la Monte and Dr. Jack Wands of Brown University in the year 2008. This hypothesis postulated that Alzheimer's disease may be called type 3 diabetes for it bears many similarities with glucose metabolism disorder type 2 diabetes. Their concept arises from the basic principle that insulin is fundamental to blood sugar regulation, but it is also the case with the brain. When brain cells become insulin-resistant, they lose access to glucose, impairing their function.
Research published in the Journal of Diabetes Science and Technology supports this hypothesis by indicating that insulin resistance can be a significant contributor to the occurrence of dementia, also referred to as Alzheimer's. The symptoms of memory loss and diminished reasoning are associated with impaired glucose metabolism in the body, especially in the cerebral tissue.
Although type 3 diabetes is not a "medical term," its symptoms correlate well with Alzheimer's diseases that are known to reduce the ability to think in an efficient manner and bring down brain health. These signs are:
- Loss of memory, especially short-term.
- Poor judgment and judgment ability
- Failure in recognizing people or places familiar once.
- Failure in the process of reading, writing or processing numbers
- Anxiety, agitation, or mood changes.
- Disorganized thoughts or confusion
- Lack of impulse control
As the disease advances, patients may be afflicted with severe complications including an inability to swallow or control their bodily functions. In the final stages, most patients die from fatal complications such as aspiration pneumonia.
This may not be well understood with regards to type 3 diabetes, or the exact link between insulin resistance and Alzheimer's disease. Some identified contributing factors include the following:
Insulin acts as an important regulatory mechanism of brain functions such as memory and cognition. The reduction in insulin signaling may impair metabolism of brain cells, thus bringing about neurodegeneration.
These diseases show a strong relationship and those individuals diagnosed with type 2 diabetes have double chances of getting Alzheimer's. In the two, the main causes can be chronic inflammation, oxidative stress, and a defect in glucose metabolism.
Insulin resistance associated with obesity, stress, and an unhealthy diet is considered a cause that may increase the chances of Alzheimer's disease.
Researches in Frontiers in Neuroscience and The Lancet Neurology have also highlighted that drugs used for antidiabetic medication may be crucial for the prevention or at least slowing down the course of Alzheimer's.
In 2022, in a study in Pharmaceuticals, researchers studied biomarker uptake in brain regions implicated in the faulty uptake and metabolism of blood sugar in Alzheimer’s patients.
Emerging Therapies
Research into such treatments as intranasal insulin has also been promising. Intranasal delivery of insulin directly to the brain has been reported to enhance glucose uptake by brain cells, improve memory, and boost cognitive performance. While such clinical trials have been shown to be successful, additional research is needed for safety and efficacy.
Medications
For patients being aggressive or agitated, antipsychotic drugs may be prescribed; however, therapies such as cognitive rehabilitation as well as cognitive stimulation therapy serve to preserve memory and executive function.
Lifestyle Interventions
Diet, exercise, and stress management are critical in preventing and managing insulin resistance. A review in the Journal of Alzheimer's Disease also highlighted the benefits of Kirtan Kriya meditation, which can regulate genes involved in insulin and glucose metabolism, improve sleep, and reduce inflammation.
Although type 3 diabetes is not officially recognized, its connection to Alzheimer’s disease underscores the importance of proactive measures for brain health. Some prevention strategies include:
1. Healthy Diet
Consuming a balanced diet rich in antioxidants, whole grains, and healthy fats may support brain health.
2. Regular Exercise
Physical activity improves insulin sensitivity, reduces inflammation, and enhances overall metabolic health.
3. Stress Reduction
Mindfulness practices, including meditation, have been shown to lower stress levels, which can reduce the risk of cognitive decline.
The term type 3 diabetes brings out the complex relationship between metabolic disorders and brain health. Even though it is not a recognized medical condition, the concept emphasizes the crucial role of insulin in brain function and its possible contribution to Alzheimer's disease. Continued research will hopefully provide hope for therapies such as intranasal insulin and lifestyle modifications.
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Why looking beyond the obvious can save lives.
A 50-year-old woman recently came to my clinic seeking a second opinion.
For weeks, she had been treated for asthma. She was using inhalers regularly, yet her cough persisted, and her breathlessness continued to worsen, even while resting. Something about her story didn't add up.
A simple chest X-ray revealed the real problem: a massive pleural effusion, a large collection of fluid surrounding the lung and preventing it from expanding normally. Further evaluation confirmed the underlying cause, lung cancer that had spread to the pleura, the thin membrane lining the lungs.
Her symptoms were genuine. The diagnosis, however, was not asthma.
Cough and breathlessness are among the most frequent reasons people visit a doctor. In most cases, the cause is something common, such as asthma, allergies, or a respiratory infection.
But common symptoms do not always point to common diseases. The key is recognizing when the clinical picture no longer fits.
If symptoms:
Then it is time to pause, reassess, and investigate further rather than simply changing medications.
In this patient's case, inhalers could never have relieved the pressure caused by fluid around the lung. Nor could they have treated an underlying tumor. The delay didn't change the diagnosis, but it delayed the answers, appropriate treatment, and the opportunity to plan the next steps.
For decades, lung cancer was largely associated with older men who smoked heavily. That picture has changed.
In our practice, we diagnose approximately two to three new cases of primary lung cancer every three months, and nearly 40% of these patients are women or individuals who have never smoked.
Increasingly, we are seeing:
If we continue to associate lung cancer only with smoking, we risk missing a significant proportion of patients who need timely diagnosis.
Asthma should not become a permanent label simply because someone has a cough or wheeze.
When symptoms fail to improve within a few weeks of appropriate treatment, it is important to step back, reconsider the diagnosis, and investigate further.
A chest X-ray remains one of the most valuable first-line investigations.
In just a few minutes, it can identify pneumonia, tuberculosis, heart failure, pleural effusion, lung masses, and many other conditions that require an entirely different treatment approach.
Even in an era of advanced imaging and artificial intelligence, the fundamentals of clinical medicine remain indispensable.
When detected early, lung cancer is often more treatable and offers significantly better outcomes.
Even in advanced disease, timely diagnosis can make an enormous difference. Procedures such as draining pleural fluid, initiating targeted therapy, immunotherapy, or palliative treatment can greatly improve both symptoms and quality of life.
Seek medical evaluation if you experience:
I often remind my patients that the body rarely sends repeated signals without a reason.
A persistent cough or unexplained breathlessness should never be dismissed simply because it resembles asthma. While asthma is common, it is only one of many possible causes.
Artificial intelligence can generate a list of potential diagnoses within seconds. But medicine is about more than identifying possibilities. It requires listening carefully, examining thoughtfully, choosing the right investigations, and connecting the clinical clues.
The woman who came to me was looking for reassurance.
Instead, she received something far more important: a correct diagnosis, a clear treatment plan, and the opportunity to move forward with certainty.
Because every cough is not asthma. And every breath deserves an explanation.
(By Dr. Sachin Kumar, Director – Pulmonology & Critical Care Medicine, Sakra World Hospital, Bengaluru)
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Tadalafil, a widely used drug for erectile dysfunction and enlarged prostate symptoms, may increase the risk of glaucoma, the leading cause of blindness, in men with lower urinary tract symptoms (LUTS), according to a new study.
Although the study identified a significant association, the researchers emphasized that it was observational and does not prove that tadalafil directly causes glaucoma.
However, they suggested that men taking tadalafil long-term for LUTS may benefit from regular eye examinations, particularly those with existing glaucoma risk factors such as a family history of the disease or ocular hypertension.
Researchers from the National Taiwan University Hospital in Taipei, Taiwan, found that men taking tadalafil for LUTS were:
The findings were published in the British Journal of Ophthalmology.
Also read: Israeli Scientists Find Surprising New Benefit of Viagra: It May Help Stop Cancer Spread
The researchers analyzed health data from 73,854 men aged 40 years and older with a history of lower urinary tract symptoms.
Half of the participants had been prescribed tadalafil or another phosphodiesterase type 5 inhibitor (PDE5i) for up to five years, while the remaining participants received other treatments.
The increased glaucoma risk remained consistent, particularly among men aged over 50 years.
Tadalafil works by relaxing smooth muscles and improving blood flow. Besides treating erectile dysfunction, it is also prescribed to relieve urinary symptoms caused by an enlarged prostate, such as frequent urination and urgency.
Previous studies have linked PDE5 inhibitors to several eye-related side effects, and the new findings add to concerns about their long-term effects on eye health.
"Tadalafil use for lower urinary tract symptoms was associated with a significant increase in the risk of glaucoma, ocular hypertension, primary open-angle glaucoma and initiation of glaucoma treatment in a large, multinational, real-world cohort," the researchers concluded.
Read More: GLP-1 Drugs Like Mounjaro, Ozempic Linked To 82 Deaths In UK, 162 In US
Lower urinary tract symptoms (LUTS) are common urinary problems that affect the storage or passage of urine. They are particularly common in elderly men and are often linked to conditions such as an enlarged prostate, an overactive bladder or problems affecting the body's fluid balance.
Common symptoms include:
Glaucoma is a group of eye diseases that can damage the optic nerve, potentially leading to irreversible vision loss and even blindness if left untreated.
It is a chronic disease that affects an estimated 80 million individuals globally, according to the World Glaucoma Association.
A major challenge with glaucoma is its lack of symptoms in the initial stages. As a result, the condition is often diagnosed at an advanced stage, where treatment yields the least results. More than 75 percent of glaucoma cases globally remain undiagnosed.
When to see a doctor for glaucoma:
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For years, diet sodas have enjoyed a pretty good reputation. They offered the sweetness without the sugar, the fizz without the guilt, and for many people, they became an easy replacement for regular soft drinks. It is not hard to see why. Whether it is an afternoon craving, something to sip with lunch, or a way to satisfy a craving without reaching for sugar, diet drinks have quietly become part of many people's daily routine. However, a major new study is making people look at those drinks a little differently. Researchers have found that people who regularly consumed higher amounts of artificial sweeteners showed faster declines in memory and thinking skills over time. It does not mean your occasional Diet Coke is suddenly a problem. But if you cannot remember the last day you went without one, the findings are definitely worth knowing.
The study followed 12,772 adults in Brazil over eight years, with the average age of participants being 52. It is the largest and longest study so far looking at how artificial sweeteners may be linked to brain health. Researchers examined seven commonly used low- and no-calorie sweeteners found in ultra-processed products like sodas, flavoured water, sugar-free yoghurt and low-calorie desserts. These included:
Throughout the study, participants completed tests that measured memory, verbal fluency, and processing speed. After taking other health factors into account, researchers noticed a clear pattern. People who consumed the highest amounts of artificial sweeteners experienced cognitive decline 62% faster than those who consumed the least. According to the researchers, that difference was roughly equal to 1.6 years of additional brain ageing.
Even people in the middle consumption group showed a 35% faster decline, equivalent to about 1.3 years of brain ageing. Out of the seven sweeteners studied, six showed an association with faster cognitive decline. The only one that did not was the Tagatose.
One finding stood out more than the rest. Most people tend to think of memory problems as something that only becomes a concern later in life. This study suggested that may not be the full picture. The link between artificial sweeteners and cognitive decline was strongest in adults under the age of 60. Researchers believe this could mean that the habits people build during midlife play a much bigger role in long-term brain health. The association was also stronger among people with diabetes, who are often more likely to choose artificially sweetened foods and drinks instead of sugary ones. Among all the areas tested, memory appeared to take the biggest hit.
This is where the conversation becomes important.
“Our findings do not suggest that drinking an occasional diet soda is harmful,” Claudia Kimie Suemoto of the University of São Paulo said. “Rather, they raise questions about the potential consequences of frequent, long-term consumption of artificial sweeteners.”
The study was observational, which means it identified the link, but it cannot say for sure that the sweeteners themselves caused the decline. That is a big difference. Lead researcher Claudia Kimie Suemoto from the University of São Paulo said: “Based on our study alone, I would not tell someone to stop drinking diet soda because of concerns about cognitive impairment”.
The findings also support earlier research. A 2017 study from the Framingham Heart Study reported a similar association between artificially sweetened beverages and a higher risk of stroke and dementia. Scientists say the evidence is growing, but there is still more to understand before firm conclusions can be made.
Read Also: UK Woman Dies After Sudden Abdominal Pain Following Increase In Her Mounjaro Dose
The answer is probably not to swear off diet soda forever. Instead, experts suggest taking a closer look at how often you are reaching for it. If one can has quietly turned into several every day, it may be worth cutting back little by little. Whenever you want a Diet Coke, go for plain water, sparkling water, unsweetened tea, or black coffee. This can help reduce your overall intake without making the change feel overwhelming. The goal is not perfection; it is balance.
There is no reason to panic over a single can. But if sugar-free drinks have become something you rely on every day without really thinking about it, this study is a good reminder that even habits that seem harmless deserve an occasional second look. Sometimes the healthiest changes start with asking a simple question: "Do I really need another one?"
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