What Is Alkaptonuria? The Rare Disease That Turns Your Pee Black – Here’s Why

Updated Feb 7, 2025 | 08:00 AM IST

SummaryAlkaptonuria is a rare genetic disorder that causes black urine due to homogentisic acid buildup, leading to joint pain, cartilage damage, and skin discoloration. It has no cure but can be managed.
What Is Alkaptonuria? The Rare Disease That Turns Your Pee Black – Here’s Why

Image Credit: Canva

A condition, known commonly as "black urine disease" or Alkaptonuria is a rare genetic disorder involving protein metabolism, and it has its root in the mutation of the homogentisate 1,2-dioxygenase gene, which in turn causes homogentisic acid accumulation in the body. The appearance of dark urine after exposure to air is due to this kind of accumulation; however, a variety of symptoms can be expected, such as joint stiffness, changes in pigmentation, and other long-term health complications. Although the prevalence has been estimated to be between 1 in 250,000 and 1 in 1 million people in the United States, its effects are indeed high on those affected.

Alkaptonuria is an autosomal recessive disease, meaning that the child must inherit a defective copy of the HGD gene from both parents. If both parents are carriers, their offspring have a 25% chance of inheriting two faulty genes and developing alkaptonuria. The condition is genetic but is often not diagnosed for years because it progresses slowly and its early symptoms appear to be harmless.

Symptoms of Alkaptonuria

The most characteristic and common initial symptom of alkaptonuria is dark urine. The reason for this is due to the fact that excess HGA is excreted in the urine and upon oxidation in the presence of air, it gives the urine a brown or black color. Though it is often considered cosmetic, the long-term accumulation of HGA within the connective tissues produces more complicated health problems.

Progressive joint pain and stiffness: The accumulation of HGA in cartilage leads to early-onset osteoarthritis, making movement increasingly difficult over time.

Skin and eye pigmentation changes: Affected individuals may develop bluish or grayish discoloration of the sclera (white part of the eye) and the skin, particularly in areas exposed to friction.

Cardiovascular and respiratory problems: With age, HGA accumulation can lead to valve calcifications in the heart and stiffening of connective tissues in the respiratory tract, which can cause problems in middle and old age.

Decreased mobility and spinal problems: The spine may become stiff and painful due to chronic cartilage degeneration.

These symptoms usually begin to manifest during adulthood, leading to severe complications in a person's 40s or 50s and significantly affecting the quality of their life.

How is Alkaptonuria Diagnosed?

Because of its rarity, alkaptonuria is often mistaken or overlooked early in life. However, there are several ways to confirm the condition:

Urine Testing: The gold standard in the diagnosis is the testing of urine samples for high levels of homogentisic acid via gas chromatography. In case of oxidation, which changes the color of urine to black, it is indicative of alkaptonuria.

Genetic Testing: Confirmatory genetic testing reveals mutations of the HGD gene to diagnose the condition conclusively.

Blood Tests: High levels of HGA in the blood can be used as further evidence.

Imaging Studies: X-rays and MRIs will expose cartilage and joint damage characteristic of alkaptonuria.

Management of Alkaptonuria: Is There A Cure?

At present, there is no cure for alkaptonuria; however, various treatment approaches can reduce its symptoms and slow the disease's progress:

Nitisinone Therapy: Nitisinone is a drug that inhibits the production of HGA. It has been shown to reduce HGA levels and slow tissue damage. However, it needs to be taken under close medical supervision because of potential side effects.

Low-Protein Diet: Since HGA is a byproduct of protein metabolism, reducing protein intake—especially foods rich in tyrosine and phenylalanine—may help decrease HGA production.

Pain Management: OTC pain relievers and anti-inflammatory medications can be used to relieve joint pain and stiffness.

Physical Therapy: Exercise regularly, as it may improve mobility and strengthen muscles, thus reducing strain on affected joints.

Surgical Interventions: Most people with alkaptonuria develop severe osteoarthritis necessitating joint replacement in their old age. Also, some may require heart valve replacement surgery if cardiovascular complications develop.

Life with Alkaptonuria

Although alkaptonuria is not fatal, it severely affects the quality of life. The progressive deterioration of the joints and associated symptoms can make everyday activities difficult, requiring lifestyle changes and medical interventions. The disease may cause premature aging of the joints, requiring walking aids and mobility assistance earlier than expected.

Ongoing research will continue to work on improving the treatment options by focusing on gene therapy and alternative enzyme replacement therapies. However, because of its rarity, the clinical trials and research remain sparse.

As genetic research advances, more hope for better management and possible curative approaches for alkaptonuria exists. Scientists are searching extensively for enzyme replacement therapies and innovative drugs that can target the root cause of the disorder. Being aware and being diagnosed early helps individuals better their condition and ultimately have better long-term health outcomes.

Alkaptonuria is a striking example of how one gene mutation can have widespread effects on the body. Though still a rare and often misunderstood condition, growing awareness and advances in treatment are paving the way for better care. If you or a loved one suspect symptoms of alkaptonuria, it is essential to seek early diagnosis and medical guidance to manage the disease effectively and preserve quality of life.

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Want to Avoid Dementia? Start These 3 Habits in Your Late 40s, Study Suggests

Updated Aug 7, 2026 | 01:05 PM IST

SummaryMaintaining healthy blood pressure, controlling blood sugar, and avoiding smoking between the ages of 48 and 68 lived, on average, nearly 13 additional years without dementia.
Want to Avoid Dementia? Start These 3 Habits in Your Late 40s, Study Suggests

Credit: iStock

Worldwide, more than 57 million people live with dementia, experiencing symptoms such as short-term memory loss, difficulty finding words, confusion about time or place, trouble with complex tasks, and changes in mood or personality. Around 10 million new cases are diagnosed every year.

Recent studies suggest that the average lifetime risk of developing dementia after age 55 is about 42%.

A new study has found that maintaining healthy blood pressure, controlling blood sugar, and avoiding smoking during middle age could significantly reduce the risk of developing dementia.

People who maintained these three health measures between the ages of 48 and 68 lived, on average, nearly 13 additional years without dementia, according to the study published in the journal Neurology Open Access.

"Our findings argue that people need to actively avert these factors in midlife as a strategy for preserving brain health for more than a decade," said study senior investigator Josef Coresh, Professor in the Department of Population Health at NYU Langone.

"Discovering new ways to delay dementia is crucial with 42% of Americans at risk for developing the condition at any time after age 55," he added.

How Was the Study Conducted?

Researchers analyzed data from the Atherosclerosis Risk in Communities (ARIC) Study, an ongoing community-based study that began in 1986. It has tracked participants for decades, measuring midlife vascular risk factors and the development of dementia.

The analysis included 12,409 adults with an average age of 56, all of whom were free of dementia at the start of the study. Researchers assessed three key risk factors:

  • High blood pressure
  • Diabetes
  • Smoking
The participants were followed for an average of 26 years. During this period:

  • 3,008 people developed dementia.
  • 5,238 died without developing dementia.
Those with none of the three risk factors lived nearly 13 years longer without dementia than those with all three risk factors—30 years versus 17 years from the start of the study.

Key Findings

Researchers also examined how midlife cardiovascular risk factors affected dementia-free survival across different demographic groups.

Among participants with all three risk factors:

  • Women lived an average of 18.1 years without developing dementia, compared with 16.6 years for men.
  • White participants lived an average of 19.6 years without dementia, compared with 16.0 years for Black participants.
"These results suggest that vascular risk reduction may benefit all groups, but that certain populations, such as Black adults, may especially benefit from targeted prevention efforts," Dr. Coresh said.

"Hopefully, these results will encourage people to stop smoking and watch their vascular health closely from age 48 on."

What Is Dementia?

Dementia is an umbrella term for a significant decline in mental function that interferes with daily life. It commonly affects memory, thinking, and reasoning abilities and is caused by underlying conditions such as Alzheimer's disease or vascular dementia.

While there is currently no cure, the WHO says up to 45 per cent of dementia risk can be prevented or delayed by addressing modifiable risk factors such as tobacco and alcohol use, physical inactivity, social isolation, air pollution, and noncommunicable diseases (NCDs), including high blood pressure and diabetes.

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Climate Change And Progressive Urbanization Call For An Integrated Approach To Infectious Disease Surveillance

Updated Aug 7, 2026 | 07:00 AM IST

SummaryWarming temperatures and erratic rainfall alter mosquito breeding cycles and pathogen incubation periods, while floods can create sudden transmission spikes in a population. On the other hand, rapid urbanization increases overlap among human, animal, and vector habitats.
Climate Change And Progressive Urbanization Call For An Integrated Approach To Infectious Disease Surveillance

Credit: iStock

Through the first quarter of the twenty-first century, it has been clear that the global menace of infectious diseases has become very different in terms of their causal factors and predictability.

A 2022 review in Nature Reviews Microbiology by Princeton professors Rachel Baker and Jessica Metcalf aptly pointed out how climate change, urbanization, and wider travel and trade determine when, where, and how outbreaks of infections happen. Examples of such outbreaks are numerous globally, viz. SARS, H1N1, MERS, Ebola, Zika, and COVID-19 outbreaks. It has also been realized by biomedical scientists that more than half of all known pathogenic diseases have at some point been worsened by climate-change-related events.

As a result, research on climate-disease links has surged since the recent pandemic.

Evidence supporting this climate-disease relationship is also abundant in the Indian context. A major example is our experience with dengue infections, which are clearly losing their seasonal predictability. Contrary to its usual temporal link with the monsoon, India has encountered an unusually early transmission in 2026, with nearly 7,000 cases reported by end-February, as per the National Center for Vector-Borne Diseases Control data. The vector has also expanded its geographical distribution, for example into Himalayan towns such as Darjeeling over the past decade.

Meanwhile, the Integrated Disease Surveillance Program in India also reports bimodal waves of influenza transmission and infections with respiratory syncytial virus (RSV) surge during the monsoon. These provide evidence that overlapping and compressed disease seasons are becoming more common.

Warming temperatures and erratic rainfall alter mosquito breeding cycles and pathogen incubation periods, while floods can create sudden transmission spikes in a population. On the other hand, rapid urbanization increases overlap among human, animal, and vector habitats. India is expected to have an urban population of close to 600 million by 2031. This will further intensify livestock density, land-use change, and human-wildlife contact, raising the risk of zoonotic spillovers.

As is evident globally now, global travel and trade will carry the pathogens across borders way faster than health systems can respond. Thus, reactive outbreak responses, of testing, isolating, and reporting only after cases show a surge, are strategically too slow. However, genomic and wastewater surveillance offer scalable alternatives. For example, such efforts in India could detect SARS-CoV-2 variants in sewage much before case counts rose in a population.

Similar experience has been gathered in cities like Bengaluru, wherein wastewater monitoring could track influenza and RSV circulation independent of individual testing. Artificial intelligence and machine learning models further add to the forecasting capacity. Modelling climate, land-use, and animal-movement data can flag likely zoonotic spillover risks well before an outbreak begins.

India's national zoonotic disease prioritization exercise and state-level One Health pilot studies in Gujarat and Rajasthan show that human, veterinary, and environmental data must be integrated. Such interdisciplinary cohort research, tracking populations across seasons and geolocations, can achieve usable forecasts integrating discrete data. Thus, building such predictive, One Health-oriented research and surveillance infrastructure will be imperative for India to achieve optimal pandemic preparedness.

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Following A Western Diet? Changes In Your Gut Bacteria Could Increase Colon Cancer Risk

Updated Aug 6, 2026 | 08:00 PM IST

SummaryA recent study has shed light on how western-style diets could increase the risk of colorectal cancer among younger people.
Gut Bacteria May Explain Why Western Diets Raise Colon Cancer Risk, Study Finds

Credit: AI

It has been long suspected that Western diets could contribute to the risk of colorectal cancer. The theory may finally have a clearer scientific explanation.

A new study suggests that gut bacteria can convert compounds produced by high-fat, low-fibre diets into cancer-causing chemicals. The research sheds light on how unhealthy eating habits may lead to cancerous tumour growth in colon in the long term.

What Did The Study Find?

Published in the journal Gut, the research was led by Dr. Annika Osswald (first author) and Dr. Soeren Ocvirk (corresponding author), along with a large team of international scientists.

The collaboration included researchers from Technical University of Munich (TUM), Germany, German Institute of Human Nutrition (DIfE), RWTH Aachen University, Freie Universität Berlin, University Hospital of Regensburg, and other institutions.

Researchers found that a western-style diet, which is commonly high in red and processed meat, saturated fats, refined carbohydrates and ultra-processed foods, significantly changes the composition of the gut microbiome.

These altered bacteria then modify bile acids in ways that promote inflammation and create an environment that accommodates the development of colorectal cancer tumours.

According to the researchers, diet alone is not the only factor. The trillions of microbes living in the intestine determine how food is processed, producing metabolites that can either protect the gut or damage it.

The study found that specific bacterial groups transformed bile acids into compounds that stimulated tumour growth in the colon.

This provides one of the strongestt explanations yet for why western dietary patterns have consistently been associated with higher risk of colorectal cancer.

"Our findings highlight the critical interaction between diet, gut microbes and cancer biology," the researchers noted, adding that targeting the microbiome could become a future strategy for preventing colorectal cancer.

Also read: Why English Actor Peter Duncan Is Advocating For Focal Therapy After His Prostate Cancer Treatment?

Negative Effects Of Western Diet

A western diet typically includes:

  • High amounts of processed and red meat
  • Fried foods and saturated fats
  • Sugary drinks and desserts
  • Refined grains
  • Low intake of fruits, vegetables, legumes and whole grains

Previous research has repeatedly linked this eating pattern with obesity, diabetes, heart disease and colorectal cancer, but scientists have long found it challenging to explain the exact cause until now.

Also read: AI-Powered Blood Test Detects Liver Cancer Across Diverse Populations, Shows Promise In Earlier Diagnosis

Importance Of Gut Microbiome

The human gut is home to trillions of bacteria that help digest food, regulate immunity and produce beneficial compounds like fatty acids.

A fibre-rich diet supports good bacteria that reduce inflammation, whereas diets high in fat and processed foods can cause microbial imbalance.

The new findings suggest this imbalance changes how bile acids are metabolised, increasing the production of molecules capable of damaging the colon and supporting cancer growth in the long run.

Also read: WHO Cancer Agency Flags 3 Common Medicines As Carcinogenic: What It Means For Millions Of Patients

Colorectal Cancer Is Rising Among Younger Adults

Earlier research has linked harmful gut bacteria, including toxin-producing E. coli, with DNA damage that may begin early in life and contribute to the rise of colorectal cancer among younger people.

However, the latest findings do not prove diet alone causes cancer. Genetics, obesity, physical inactivity, sedentary life, smoking and alcohol consumption also influence risk.

However, they say maintaining a fibre-rich diet with fruits, vegetables, legumes and whole grains may help preserve a healthier gut microbiome and lower long-term colorectal cancer risk.

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