Blog

Blowing into a conch shell could help tackle the symptoms of a sleep disorder that affects millions of people across the UK, according to a study.

Conch blowing, also known as shankh blowing, is an ancient ritual that involves breathing in deeply and exhaling into the spiral-shaped shell.

The practice could improve sleep for patients with obstructive sleep apnoea (OSA), which usually needs to be treated with uncomfortable machinery, according to the research.

OSA occurs when breathing starts and stops during sleep. Symptoms include loud snoring and making gasping or choking noises.

Thirty people living with the disorder and aged between 19 and 65 were involved in the trial, led by researchers at the Eternal Heart Care Centre and Research Institute in Jaipur, India.

About half of the group were taught how to use the shell, while the others carried out deep breathing exercises. Both groups were encouraged to practise their techniques for at least 15 minutes, five days a week.

Six months later, the trial found that those who had practiced shankh blowing were 34% less sleepy during the day. They also had higher blood oxygen levels during the night, and four to five fewer OSA episodes an hour on average.

“Shankh blowing is a simple low-cost breathing technique that could help improve sleep and reduce symptoms without the need for machines or medication,” said Dr Krishna K Sharma, who led the research.

“The way the shankh is blown is quite distinctive. This action creates strong vibrations and airflow resistance, which likely strengthens the muscles of the upper airway, including the throat and soft palate, areas that often collapse during sleep in people with OSA.”

The most common form of treatment for sleep apnoea is a continuous positive airway pressure (Cpap) machine, which involves patients wearing a mask that blows pressurised air into the nose and throat while asleep. Previous research has also found that playing a woodwind instrument could help with the condition.

Although the machines are effective, they can be uncomfortable, leading the researchers to suggest that shankh blowing could be a promising alternative.

A larger trial involving several hospitals is being planned.

“The findings of this trial are encouraging, but the small scale of the trial means it’s too soon to say for certain that conch blowing can help people manage their obstructive sleep apnoea,” said Dr Erika Kennington, the head of research and innovation at Asthma + Lung UK.

“It’s also not clear from this research why blowing through a conch shell regularly might improve someone’s symptoms. It would be good to see the conch blowing approach tested on a larger scale and compared with other proven strategies, such as limiting alcohol, staying active and maintaining good bedtime habits.

“OSA is a long-term condition, but with the right treatments and lifestyle changes, people can make a real difference to their symptoms.”

Human and mouse specimen Preparation

Tissue samples were fixed in a 10% buffered formalin solution, embedded in paraffin and sliced into flat Sect. (10-µm-thick sections were prepared for SAM, whereas 4-µm-thick sections were prepared for LM). Enzymatic digestion makes the surface irregular and causes the section to detach from the glass slide. To protect the detachment, we used an immune-coated slide for immunostaining (Muto Pure Chemicals, Tokyo, Japan).

For mouse bone tissue, the bones were provided by Dr. Y. Enomoto from the Department of Regenerative & Infectious Pathology and fixed and soaked in a 0.5 mol/L ethylenediaminetetraacetic acid (EDTA) solution (Fujifilm Wako chemicals, Tokyo, Japan) for 2 days for decalcification.

For the cytology section, residual free cells from ascites or pleural effusions were prepared to make single-cell-layer slides using a previously reported liquid-based cytology method (BD CytoRich™; Franklin Lakes, NJ, USA)¹². The slides were fixed in 95% ethanol for 10 min and postfixed in 10% buffered formalin for 45 min.

Enzyme digestion

To digest the sections, various enzymes were used, including actinase E (pronase E) (Funakoshi, Tokyo, Japan), collagenase type 2 (Worthington, Lakewood, NJ, USA), DNase 1 (Merck, Darmstadt, Germany) and α-amylase (Fujifilm Wako, Osaka, Japan). Actinase and collagenase type 2 were dissolved at 1 mg/mL in phosphate-buffered saline (PBS) containing 0.5 mM CaCl₂. α-Amylase (10 mg/mL) was dissolved in PBS (pH 7.4), and DNase 1 (0.1 mg/mL) was dissolved in 20 mM HCl containing 1 mM MgCl₂ and 1 mM CaCl₂. The enzyme solution was mounted on the section and incubated at 37 °C. The activity of each enzyme determined the incubation duration. The sections were washed in distilled water at each time point and observed with SAM. After observation, the same section was reincubated in the enzyme solution.

SAM observations

We used a SAM system (AMS-50AI; Honda Electronics, Toyohashi, Aichi, Japan) with a central frequency of 320 MHz and a lateral resolution of 3.8 μm, as previously reported^24,25,26. The tissue or cytology section was placed on the stage, and distilled water was used as the coupling fluid between the transducer and the section. The waveforms reflected from the surface and bottom of the sample were compared to measure the AOS at each point⁸. The waveform from the glass surface without a specimen was considered the zero AOS area (black) and was used as the reference. The transducer scanned the sections along the X- and Y-axis for a few minutes to capture the images. The plotted AOS value at each point generated an AOS image.

LM observation

LM slides taken from near the SAM section locations or the same section as for the SAM observation were prepared for comparison with the corresponding AOS images. Staining methods, including haematoxylin and eosin, Elastica Masson trichrome, Congo red and periodic acid-Schiff (PAS), were the same as the routine histology methods employed in the pathology laboratory.

Immunohistochemistry

We utilised the Dako REAL EnVision detection system using the peroxidase reaction with DAB for immunohistochemistry and followed the analysis procedure. The primary antibody was anti-Ki67 (MIB-1, DAKO). For antigen retrieval, histological and cytological sections were soaked in 10 mM Tris-EDTA buffer (pH 9.0) (Abcam, Tokyo, Japan) at 95 °C for 40 min. After immunostaining, the sections were counterstained with haematoxylin.

Transmission electron microscopic observation of paraffin sections

TEM observation of formalin-fixed paraffin sections was performed using previously reported methods^27,28. DAB-stained sections were fixed with 2% glutaraldehyde for 60 min for pre-fixation and then incubated with 2% osmium tetroxide for 15 min for post-fixation. The sections were dehydrated with an alcohol gradient and embedded in epoxy resin (Quetol 812, Nisshin EM, Tokyo, Japan) by heating at 60 °C for 48 h. Ultrathin 70-nm-thick sections were prepared, stained with lead and uranium acetate (Merck), and observed by JEM 1400 Plus (JEOL, Tokyo, Japan).

Statistical analysis

The means and standard deviations (SD) of the AOS values were calculated from at least five areas per slide. Mean AOS values between different tissue components and at different time points following protease digestion were compared using Student’s t-test or Welch’s t-test, as appropriate. A commercial statistical software package (BellCurve for Excel; Social Survey Research Information, Tokyo, Japan) was used to calculate the mean values for areas-of-interest, generate dot plot graphs and perform t-test analyses. Before statistical analysis, all continuous datasets were tested for normal distribution. A p-value of < 0.05 was considered statistically significant.

People who practised blowing through a conch shell regularly for six months experienced a reduction in their symptoms of obstructive sleep apnoea (OSA), according to a small randomised controlled trial published today (Monday) in ERJ Open Research.

OSA is a common sleep disorder where breathing repeatedly stops during the night due to a blocked airway. It leads to loud snoring, restless sleep and daytime sleepiness. It also increases the risk of high blood pressure, heart disease, and stroke.

Blowing the conch shell, or shankh blowing, has been part of Indian culture for thousands of years. The new research showed that people with moderate OSA who practised shankh blowing slept better, felt more alert during the day and had fewer breathing interruptions at night. The researchers say conch blowing is a simple, low-cost intervention that could help reduce symptoms without the need for medication or machines.

The study was led by Dr. Krishna K Sharma from the Eternal Heart Care Centre and Research Institute in Jaipur, India.

The standard treatment for OSA is a continuous positive airway pressure machine, or CPAP, which keeps the patient’s airway open by blowing air through a facemask throughout the night. While effective, many patients find it uncomfortable and struggle to use it consistently.

In my clinical practice, several patients reported feeling more rested and experiencing fewer symptoms after regularly practising shankh blowing – a traditional yogic breathing exercise involving exhaling through a conch shell. These observations led us to design a scientific study to rigorously test whether this simple, ancient practice could serve as a meaningful therapy for people with OSA.”

Dr. Krishna K Sharma, Eternal Heart Care Centre and Research Institute, India

The study included 30 people with moderate OSA, aged between 19 and 65, who were assessed at the Eternal Heart Care Centre and Research Institute between May 2022 and January 2024. They were tested with polysomnography, meaning they are monitored throughout a night’s sleep, and asked questions about the quality of their sleep and how sleepy they feel during the day.

They were randomly assigned to either be trained to practise blowing through a conch shell (16 patients) or to practise a deep breathing exercise (14 patients). Participants were provided with a traditional shankh used in yogic practices. They were trained in person at the clinic by a study team member before beginning home-based practice. Participants were encouraged to practise at home for a minimum of 15 minutes, five days per week. After six months, the patients were reassessed.

Compared to the people who practised deep breathing, the people who practised shankh blowing were 34% less sleepy during the daytime, they reported sleeping better and polysomnography revealed that they had four to five fewer apnoeas (where breathing stops during sleep) per hour on average. They also had higher levels of oxygen in their blood during the night.

Dr. Sharma said: “The way the shankh is blown is quite distinctive. It involves a deep inhalation followed by a forceful, sustained exhalation through tightly pursed lips. This action creates strong vibrations and airflow resistance, which likely strengthens the muscles of the upper airway, including the throat and soft palate – areas that often collapse during sleep in people with OSA. The shankh’s unique spiralling structure may also contribute to specific acoustic and mechanical effects that further stimulate and tone these muscles.

“For people living with OSA, especially those who find CPAP uncomfortable, unaffordable, or inaccessible, our findings offer a promising alternative. Shankh blowing is a simple low-cost, breathing technique that could help improve sleep and reduce symptoms without the need for machines or medication.

“This is a small study, but we are now planning a larger trial involving several hospitals. This next phase will allow us to validate and expand on our findings in a broader, more diverse population and assess how shankh blowing performs over longer periods. We also want to study how this practice affects airway muscle tone, oxygen levels and sleep in greater detail. We’re particularly interested in comparing shankh blowing with standard treatments like CPAP, and in examining its potential help in more severe forms of OSA.”

Professor Sophia Schiza, Head of the ERS group on sleep disordered breathing, based at the University of Crete, Greece, who was not involved in the research said: “Obstructive sleep apnoea is a common disease around the world. We know that OSA patients have poor quality of sleep, and higher risks of high blood pressure, strokes and heart disease. A proportion of patients experience sleepiness during the day. While CPAP and other treatments are available based on careful diagnosis of disease severity, there is still need for new treatments.

“This is an intriguing study that shows the ancient practice of shankh blowing could potentially offer an OSA treatment for selected patients by targeting muscles training. A larger study will help provide more evidence for this intervention which could be of benefit as a treatment option or in combination with other treatments in selected OSA patients.”