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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Leptospirosis gained attention after its cases surged in Kerala recently. The infection has also been reported in Maharashtra, Gujarat, Tamil Nadu, and Karnataka. The bacterial infection typically spreads via contact with water or soil that has been contaminated by the urine of animals infected with leptospirosis, especially during floods.
As monsoons are right at our doors, know why it is important to detect and nab dangerous infections like leptospirosis early.
Leptospirosis is a potentially serious bacterial infection sometimes called the "rat fever" because it can cause symptoms similar to the typical symptoms of common viral infections, which may not be noticeable in the early stages. It is caused by the bacteria of the genus Leptospira that are excreted in the urine of infected animals, including rats, cattle, dogs, and pigs.
In the monsoon season, there is a risk of waterlogging and contaminated animal urine mixing with floodwater and soil. Infestation occurs through direct contact with contaminated water or mud on cuts or abrasions or on the mucous membranes of the mouth, nose, and eyes. Those involved in outdoor work, sanitation, farming, construction, or who are walking in flooded streets are especially at risk.
Health and Me spoke to Dr. Sundar Krishnan, Senior Consultant - Internal Medicine, KIMS Hospital, Thane, about how to tackle leptospirosis this monsoon.
Dr. Krishnan says, “In the early stages, it may have flu-like symptoms, and that makes early recognition challenging. Symptoms are sudden onset of high fever, chills, very severe headache, muscle pain especially in the calves and lower back, fatigue, nausea, vomiting, and red eyes.”
The expert also said that occasionally, the patient may also have abdominal pain or diarrhea. He also says it can escalate quickly to jaundice, kidney failure, difficulty breathing, meningitis, internal bleeding, or multi-organ failure and can require immediate medical care.
Dr. Krishnan recommends several prevention tips to tackle leptospirosis in monsoon:
If leptospirosis is diagnosed early and treated with antibiotics, recovery is much quicker, avoiding life-threatening complications. But if detection and treatment are delayed, the kidneys, liver, lungs, and even the brain may be affected.
The expert advises that people who are ill after being exposed to flood water and are facing fever or flu-like symptoms for more than two days should also seek medical help as soon as possible, informing their doctor about their flood water exposure.
Even though the risk of leptospirosis is high during the monsoon, the best way to steer clear of this infection is to educate the masses about its symptoms and prevention. Early clinical intervention can help de-escalate the situation promptly.
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Headaches are one of the most common health complaints and are often caused by stress, lack of sleep, dehydration, excessive screen time, skipped meals, or other lifestyle factors. While most headaches are benign, experts said that frequent or unusual headaches should not be ignored, as they may signal an underlying medical condition that requires evaluation.
The experts told HealthandMe that paying attention to changes in headache frequency, pattern, and associated symptoms can help identify when medical attention is necessary.
According to Dr. Rajneesh Kummar, Vice Chairman & Unit Head, Neurology, Max Super Speciality Hospital, Dwarka, one of the most common concerns is increasing frequency.
“If someone who previously experienced occasional headaches starts getting them several times a week or finds that painkillers are needed more often than before, it is worth getting evaluated,” he told HealthandMe.
“People should seek medical attention if they have headaches more than 10 to 15 days a month, if the headaches are getting worse, or if they are beginning to interfere with work, daily activities, or quality of life,” added Dr. Praveen Gupta, Chairman, MAIINS, Marengo Asia Hospitals, Gurugram. He also noted that medication-overuse headaches can result from taking painkillers regularly, leading to a cycle of recurrent pain.
Also read: Shingles Vaccine May Help Fight Dementia, Suggest Studies
A change in the pattern of headaches should not be ignored. Dr. Kummar said a headache that feels different from what a person has experienced in the past, particularly after the age of 50, deserves medical attention. Headaches that wake a person from sleep, are worse in the early morning, or are associated with vomiting should also be assessed further.
Dr. Gupta advised prompt medical evaluation for people over the age of 50 who develop a new type of headache. He also recommends seeing a doctor if a person has a history of cancer, a weakened immune system, or develops a headache after a head injury.
The neurologists highlight several "red flag" symptoms that require urgent medical assessment. They advised immediate consultation if a headache is accompanied by
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Dr. Kummar stated that many people worry that every headache is related to a brain tumor or another serious brain disorder. Fortunately, this is rarely the case.
However, persistent or unusual headaches should not be self-diagnosed, and timely consultation helps identify the cause and ensures appropriate treatment before the problem begins affecting quality of life, the expert said.
Dr. Gupta told HealthandMe that early diagnosis can help manage common neurological disorders such as migraines, cluster headaches, and chronic tension-type headaches. A thorough history, neurological examination, and imaging studies, when appropriate, can help determine the cause.
The experts emphasize that if headaches are becoming more frequent, changing in patterns, or affecting daily life, it is time to consult a neurologist. Early diagnosis can provide relief, prevent complications, and improve overall quality of life.
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Several recent studies suggest that older adults who receive the shingles vaccine may be less likely to develop dementia, a condition affecting more than 57 million people worldwide.
Shingles is a painful viral infection caused by the reactivation of the varicella-zoster virus (VZV), which can remain dormant after chickenpox and later trigger a blistering rash and severe nerve pain.
A June 2026 study published in the Annals of Internal Medicine suggests that one in 17 dementia cases could potentially be prevented through shingles vaccination.
Researchers at Brown University found that older adults who received the recombinant shingles vaccine (Shingrix) after a stay in a skilled nursing facility had a 24% lower risk of being diagnosed with dementia over four years than those who were not vaccinated.
The study analyzed Medicare and health records from more than 500,000 adults aged 66 and older admitted to skilled nursing facilities. Researchers compared those who received at least one dose of Shingrix with those who remained unvaccinated.
“A lot of previous studies with similar results focused on an older vaccine,” said study author Kaley Hayes, an assistant professor at Brown University’s School of Public Health.
“This study looks at the newest vaccine only in an older, vulnerable adult population who were not up to date with shingles vaccination and are at a very clear clinical point in care: entering a skilled nursing facility.”
The findings add to growing evidence linking shingles vaccination with a lower risk of dementia.
Also read: How To Spot Leptospirosis, Dengue, Malaria During Monsoons? Early Symptoms Not To Neglect
Researchers believe the vaccine may help protect the brain by preventing shingles and the inflammation caused by the virus.
Shingles can cause a “war zone” of inflammation in the brain, said Dr. Jennifer Pauldurai, the medical director of the Inova Brain Health and Memory Disorders Program in Northern Virginia, NBC News reported.
It’s not that the shingles vaccine itself is a “magic pill,” Pauldurai said.
Rather, the vaccine guards against the disease, which is known to disrupt brain health.
The latest findings add to a growing body of international research.
A study involving more than 282,000 older adults in Wales, published in Nature in 2025, found shingles vaccination was associated with a 3.5% lower absolute risk of dementia over seven years.
Another study of more than 101,000 older adults in Australia, published in the Journal of the American Medical Association in 2025, found vaccine eligibility was associated with a 1.8% lower dementia risk over 7.4 years.
Similarly, a study involving more than 232,000 older adults in Canada, published in The Lancet Neurology in 2026, linked shingles vaccine eligibility to a 2% lower dementia risk over 5.5 years.
Read More: Sepsis: India Joins Global Trial To Screen Newborns For Deadly Drug-Resistant Infections
After a person recovers from chickenpox, the VZV virus remains dormant in nerve cells and can become active again years or even decades later, particularly when the immune system weakens.
Older adults and people with weakened immune systems are at the highest risk of developing shingles.
According to the NHS, shingles often starts with:
Seek prompt medical attention if:
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