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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Even a mild case of COVID-19 may trigger long-lasting eye problems, with new research revealing that persistent inflammation and nerve damage could be responsible for symptoms that standard eye tests often fail to detect.
The study, led by researchers at Linköping University in Sweden and published in Nature Communications, sheds light on why some COVID-19 survivors continue to experience debilitating vision issues months or even years after infection.
The research began after people who had recovered from mild COVID-19 sought medical help for persistent eye complaints. Many reported:
Many participants said the condition significantly disrupted their daily lives, preventing them from working or continuing their education.
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Researchers evaluated 100 people who developed eye problems after mild COVID-19 but had never been hospitalized. Their symptoms had persisted anywhere from three months to three years.
The findings were compared with those of 32 people who had recovered from mild COVID-19 without developing eye symptoms.
Using advanced imaging and laboratory techniques, researchers identified several abnormalities that conventional eye exams failed to detect.
The study found evidence of:
Lead author Petros Moustardas, senior research associate at Linköping University, said the findings indicate that COVID-19 may trigger a severe immune reaction in the eyes, resulting in chronic inflammation and nerve dysfunction.
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One of the most common complaints among participants was extreme sensitivity to light. Researchers found that their pupils were allowing too much light into the eyes because of impaired nerve control.
This abnormal pupil function was also associated with:
The study also identified impaired coordination between the two eyes.
Some participants developed adult-onset strabismus—commonly known as crossed eyes—a condition that is rare in adults.
Researchers believe this occurred because COVID-19 affected the nerves responsible for controlling eye muscles.
Because routine eye tests often miss these abnormalities, the research team developed two diagnostic models.
The first relies on specialized ophthalmic tests available at advanced eye clinics, while the second combines these examinations with tear fluid protein analysis to improve diagnostic accuracy.
Researchers hope these models will help doctors recognize COVID-related eye syndrome earlier and pave the way for future treatments.
"We found that the problems experienced by those affected were not detectable by standard tests. We had to perform specialised examinations to detect deviations. The puzzle pieces then fell into place, and we found explanations for the symptoms," said Neil Lagali, professor of experimental ophthalmology at Linköping University.
He added that while the findings provide important clues about how COVID-19 affects the eyes, more research is needed to develop effective treatments for those living with persistent vision problems.
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Plant-based Vitamin D3 is often marketed as a healthier or superior alternative to traditional supplements, but doctors say that's not necessarily the case.
According to Dr. Murtaza S. Bagwala, Head of Emergency Medical Services at Saifee Hospital in Mumbai, existing research shows that plant-based Vitamin D3 is just as effective as conventional Vitamin D3 in increasing the body's vitamin D levels.
"Current evidence suggests that plant-based Vitamin D3 performs similarly to conventional Vitamin D3 supplements. For people who prefer vegan or plant-based products, it is a suitable alternative," he told HealthandMe.
Echoing this view, Dr. Sudhir Kumar, Neurologist at Apollo Hospitals in Hyderabad, said that plant-derived Vitamin D3—usually obtained from lichen, algae, or modern fermentation methods—provides an animal-free option without sacrificing effectiveness.
In a post on X, he noted that while plant-based Vitamin D3 is welcome news for vegans and those seeking cruelty-free supplements, both forms work equally well. He added that there is no medical need for people to switch if they are already taking conventional Vitamin D3 supplements.
India has approved its first plant-based Vitamin D3 (cholecalciferol) ingredient, a move that could expand options for food fortification and dietary supplements while addressing the country's widespread Vitamin D deficiency.
The Food Safety and Standards Authority of India (FSSAI) has cleared VITADEE Green, developed by Fermenta Biotech, for use in health supplements, nutraceuticals and food products.
The company stated that the ingredient is produced using an India-patented process and offers a sustainable, scalable and vegetarian-friendly source of Vitamin D3.
The approval allows Indian manufacturers to incorporate the ingredient into fortified foods, beverages and dietary supplements.
It is particularly significant for vegetarians and vegans, who have traditionally had limited access to Vitamin D3 because most supplements are derived from lanolin, a by-product of sheep's wool.
The approval also supports India's broader efforts to improve nutrition through food fortification, an area where experts say Vitamin D remains a major gap.
Vitamin D3, often called the "sunshine vitamin," is produced by the body when the skin is exposed to sunlight.
It helps the body absorb calcium, maintain healthy bones and teeth, and lowers the risk of fractures. In children, severe deficiency can lead to rickets, while in adults it increases the risk of osteoporosis, muscle weakness, and falls.
Beyond bone health, Vitamin D3 also supports immune function. Research suggests low Vitamin D levels may be associated with increased susceptibility to infections and higher levels of inflammation.
The experts said the key question is whether supplementation is needed, not whether the source is plant- or animal-derived.
"The source matters mainly for ethical, dietary or personal preference—not for efficacy," Dr. Sudhir said.
Dr. Bagwala cautioned against taking high-dose Vitamin D without medical advice, as excessive intake can raise calcium levels and increase the risk of kidney stones and other complications.
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Yawning has a certain fact attached to it, which is without a doubt a reason for curiosity and amazement among people. Many of you must have noticed that when someone nearby yawns, you often end up yawning too. Even in some cases, a person yawns just after hearing the word yawn or watching someone yawn on screen.
Yawning itself is a natural physical process that involves taking a deep breath and stretching the muscles used for breathing. Some experts suggest that it may help increase alertness and leave us feeling refreshed. However, while scientists have proposed several theories about the purpose of yawning, one question continues to intrigue researchers: why are yawns so contagious?
Dr. Debanjan Pan, Consultant Psychiatrist at Saltlake Mindset, told Health and Me, "Contagious yawning may be linked to mirror neurons, which help us understand and imitate the behavior of others. Humans have survived by living in groups, and our brains are naturally wired to synchronize with the people around us. When we see someone yawn, the same neural networks in our brains may become activated, prompting us to yawn as well."
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Yawning involves taking a very deep breath, which increases oxygen intake and stimulates several parts of the respiratory system. This deep inhalation can temporarily raise the heart rate and boost blood circulation to the spinal cord and the brain, making a person feel calmer and more relaxed afterward.
According to Dr. Pan, this sense of relaxation may also explain why yawning is contagious. When we see someone else yawn, the brain's empathy circuits, particularly those linked to mirror neurons, become active. As humans are highly social beings, we often unconsciously mimic the behaviour and emotions of people around us, causing a yawn to spread from one person to another.
But there might be a question: if yawning is contagious because humans are social animals and human brains are naturally wired to synchronize with the people around them, then why doesn't coughing and sneezing have the same effect?
Dr. Vikas Mittal, Director - Pulmonologist, CK Birla Hospital, Delhi, addressed this very issue and explained, "Yawning is different than coughing and sneezing. Coughing and sneezing are protective reflexes that protect you from irritants. They can be contagious, but that contagion comes after one or two days, not immediately as is with yawning. Yawning occurs because of the brain's automatic self-mirroring networks."
Dr. Mittal further added, "What it means is when somebody yawns, then your brain starts imitating that unintentionally. Not only yawning, but other emotions like a smile, laugh, and fear can trigger the same emotion in the people around you. This is because of the same brain's automatic self-mirroring networks."
Contagious yawning appears to be more than a simple reflex, offering insights into empathy, social bonding, and the human brain.
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