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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Not every medicine carries the same level of risk. Some drugs can trigger reactions that are severe or even life-threatening. When that possibility exists, the manufacturer is required to place a special notice inside the prescribing information. This highlighted section is known as a black box warning.
A black box warning is meant to draw clear attention to the most serious dangers linked to a drug. Many medicines fall under this category. Still, having the warning in place does not automatically make the treatment unsafe. When a drug is used correctly and monitored by a trained professional, the benefits may outweigh the risks.
The sections below outline what an FDA black box warning means, why a medicine might receive one, and how it may influence your treatment plan.
A black box warning is the strongest caution that the FDA can attach to a prescription drug. You might also see it described as a boxed warning.
The presence of this warning does not mean a person should never take the medication. Instead, it alerts doctors and patients to serious potential harm. This information helps clinicians decide who is an appropriate candidate and under what circumstances the drug should be used.
Many medicines with boxed warnings remain the best or only option for certain conditions.
A drug receives this type of label when it has been linked to outcomes such as permanent injury, hospitalisation, or death. These warnings should be read carefully, and patients should discuss them openly with their healthcare provider.
Doctors follow specific precautions when prescribing drugs that carry this label to minimize unnecessary risk.
The warning sits at the very top of the medication’s official package insert. Its placement is deliberate so it stands out immediately. The text is printed inside a bold black border, which is how the term “black box” took hold.
You may not always receive the full package insert from the pharmacy. However, you might receive a medication guide if the drug is considered high-risk. These guides describe proper use and highlight major side effects. You can also look up medication guides online.
Information about boxed warnings is available from multiple sources. The FDA website, the drug manufacturer’s website, and medical reference sites used by clinicians all include these details.
Every prescription drug must go through extensive testing before it reaches the market. During this process, researchers aim to uncover risks that could require a boxed warning from the start. Even so, some side effects only appear once large numbers of people begin using the drug in everyday settings.
Because of this, most black box warnings are added after a medicine has already been approved. The FDA continues to monitor safety reports through MedWatch, a program where patients, physicians, and companies can report problems.
These reports are gathered in a database called the FDA Adverse Event Reporting System. When the agency notices a pattern of serious reactions, they investigate. If needed, they update the prescribing information and add a boxed warning so that future users are clearly informed.
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People assigned female at birth live with hormone shifts throughout their lives. These chemical messengers guide nearly every system in the body. The swings linked to periods, pregnancy or menopause are easy to recognise, but many other factors can unsettle hormone levels.
The body produces more than fifty hormones through the endocrine system, and changes in any of them can signal a deeper health concern. Low insulin may point toward diabetes. Excess cortisol can influence weight gain. Other hormones, like melatonin, rise and fall through the day as part of normal rhythm. And the gradual drop in estrogen and progesterone as women approach menopause is also expected.
Puberty, pregnancy and menopause naturally reshape hormone activity. Beyond these, several conditions can disrupt normal patterns. Problems with the adrenal gland, thyroid disorders, eating disorders, congenital adrenal hyperplasia, Cushing’s syndrome, diabetes or PCOS can all change your hormone levels. Changes may also stem from stress, certain medicines, tumours, cysts or environmental chemicals.
Interest in hormones has grown recently. Earlier this month, the Food and Drug Administration agreed to remove the boxed warning on menopause hormone therapy after reviewing the evidence. The decision prompted fresh discussion among women considering treatment. Clinicians say many patients are reaching out with new questions, especially in an era filled with quick tests and supplements marketed as hormone balancers. It can be difficult to tell when testing is truly needed.
As each hormone plays a different role, symptoms vary widely. These are some of the more frequent changes seen in people, as per UCLA Health.
1. Menstrual changes: Shifts in estrogen and related hormones can alter the monthly cycle. Periods may become heavier, lighter, irregular or go missing. Stress, diet and exercise can contribute as well, but hormonal swings remain a leading cause.
2. Hair changes: Hair often reacts quickly to hormonal shifts. Pregnancy can bring thicker strands, while imbalances may trigger hair thinning or hair growth in unexpected places. Excessive facial hair may suggest elevated androgens. Hair loss can point toward a thyroid concern.
3. Skin Changes: Hormonal shifts can influence skin colour, texture and oil production. Acne may flare during pregnancy due to rising progesterone. Darkened patches of skin may appear on areas like the neck, groin or beneath the breasts when estrogen or progesterone levels change.
4. Sexual and vaginal symptoms: Lower estrogen levels, especially with age, can reduce libido and cause vaginal dryness or pain during intercourse. Some women may experience vaginal atrophy when estrogen remains low for long periods.
5. Weight changes: Sudden weight gain or weight loss can reflect a hormonal issue. Many women notice weight gain after menopause. Thyroid disorders, PCOS and Cushing’s syndrome are also linked to changes in body weight.
6. Mood and sleep difficulties: Falling estrogen levels influence serotonin, a chemical important for stable mood. Low serotonin can contribute to anxiety, irritability or low mood. These disruptions often spill into sleep. Some women also report night sweats or trouble staying asleep.
7. Digestive issues: Estrogen and progesterone affect digestion. When these hormones shift, the gut may respond with bloating, constipation or diarrhoea. Some research has linked hormonal changes in people AFAB to irritable bowel syndrome. Many notice digestive changes around their menstrual cycle.
There is no single test that measures every hormone, and at-home kits only cover a few markers. The safest first step is to speak with your primary care doctor. They can look at your overall health and decide what evaluations are appropriate.
Diagnosis may include:
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As bird flu continues to trouble several countries, health officials in the United States have reported the first known human case of the H5N5 subtype of avian influenza. The Washington State Department of Health announced on November 14, 2025, that the virus was found in a resident of Grays Harbor County.
The patient, an older adult with existing medical issues, is currently in the hospital. Authorities noted that the individual kept poultry at home that had contact with wild birds, which is believed to be the likely source of the infection, though the investigation is still underway. Since H5N5 is newly identified in humans, many are asking whether it differs from the earlier H5N1 strain.
H5N1 is a highly pathogenic form of avian influenza that mainly affects birds but can also infect mammals, including humans. It can lead to severe illness in people and has a high fatality rate, though it rarely spreads from one person to another, as per the World Health Organization. The virus has moved across continents in wild and farmed birds and has recently been found in dairy cattle and several other mammals.
The “new” H5N1 strain refers to the 2.3.4.4b clade of highly pathogenic avian influenza (HPAI), which has caused a widespread animal outbreak since appearing in 2020. This version is a newer genetic branch of H5N1 and has swept through wild birds, poultry farms and an increasing range of mammals, including dairy herds in the United States. At present, the patient infected in the U.S. has been diagnosed with the newer H5N5 subtype.
According to the CDC, both H5N5 and H5N1 fall under the avian influenza family, with the main distinction being the type of neuraminidase (N) protein on the virus surface. H5N5 contains the N5 protein, while H5N1 carries the N1 protein. Although this genetic change can influence viral features, their overall pattern of illness and symptoms is expected to be much the same, particularly in birds and livestock.
The genetic structure is the only difference, with H5N1 strain containing a subtype of influenza A with a segmented genome while the other has a new reassortant virus formed from several subtypes, possibly including H5N1, as per National Institute of Health.
Vaccines for bird flu do exist, but they are not intended for general public use and are not easily available for everyday protection. Some vaccines have been created and stored for possible deployment in people at higher risk, such as poultry workers and farm staff, and they are also used in animals like chickens to help manage outbreaks. The United States and several other countries have stockpiled H5N1-specific vaccines that could be rolled out if the threat to humans grows. A few nations, including Finland, are already offering them to certain high-risk groups. At the moment, there is no advice for the wider public to take a bird flu vaccine, as there is no sustained human-to-human spread and no mass-market human vaccine in use.
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