Jaggery will not wash your lungs, whatever the post-Diwali WhatsApp forwards say

Jaggery has applied, by WhatsApp forward, for the post of chief lung cleaner. Your cilia, the staff who actually do the work, would like a word.

In Short

• Jaggery’s only lung reference is a 1994 study on rats
• Cilia, tiny airway hairs, quietly do the real cleaning daily
• An N95 mask and HEPA purifier beat any smog remedy

At 8 am on Dhanteras, the sun over Delhi was a pale coin behind a grey curtain. The city's air quality index stood at 389, which is "very poor", and the monitor at IIT Delhi read 473, deep in the "severe" band, according to the Central Pollution Control Board's figures reported on Nov 6.

By 8.15, a humble block of jaggery had applied, by WhatsApp forward, for the post of Chief Lung Cleaner. Its resume was impressive in length and modest in evidence. The human body, which runs a famously strict human resources department, convened an appraisal.

DOES JAGGERY REALLY CLEAN YOUR LUNGS?

The candidate's case rests mainly on a single reference, supplied in 1994 by a group of rats. Researchers at the Industrial Toxicology Research Centre in Lucknow fed the rats jaggery for up to 90 days after placing coal dust in their windpipes. The paper, in Environmental Health Perspectives, reported that the dust moved faster from the lungs to nearby lymph nodes, small bean-shaped filters of the immune system, and that the rats had fewer lung lesions, which are patches of damaged tissue.

The panel found this charming. It also noted that the testimonial came from rats, the dust was coal rather than Delhi's smog, and, as far as this reporter could find, no equivalent trial in people exists. The authors hoped jaggery might help workers in dusty jobs. A hope, the panel observed, is a lovely thing to put on a resume and a poor thing to breathe through.

WHO ACTUALLY CLEANS YOUR LUNGS?

Here the appraisal turned awkward, because the work was already being done by staff who had never asked for credit. Your airways are lined with cells carrying tiny hairs called cilia, and a thin layer of sticky mucus sits on top. Dust and germs get caught in the mucus. The cilia then beat roughly 10 to 20 times a second, sweeping it towards the throat, where you swallow or cough it out.

Scientists call this mucociliary clearance, and a review in Cold Spring Harbor Perspectives in Biology describes it as the lung's main defence. It operates all day and all night, unpaid, without a forward to its name. Cigarette smoke slows it, cold dry air can too, and conditions such as asthma and chronic obstructive pulmonary disease, a long-term lung illness, thicken the mucus. Jaggery appears nowhere on the staff roster.

WHY CAN'T JAGGERY CLEAR DELHI'S SMOG?

The candidate was asked to explain how a sweet taken after dinner would solve the problem. The problem, it emerged, is a set of particles called PM2.5, each smaller than 2.5 micrometres. A micrometre is one-thousandth of a millimetre. The US Environmental Protection Agency says an average human hair is about 70 micrometres wide, about 30 times larger than the largest of these fine particles, and that particles this small can get deep into the lungs.

Jaggery arrives by the digestive system, not the windpipe, and the panel asked how, in people, it would find its way to the particles. Nobody present could say. The panel thanked it for its optimism and noted the discrepancy in the floor plan.

WHAT SHOULD YOU DO TO PROTECT YOUR LUNGS FROM POLLUTION?

The panel then turned to the intern, an unglamorous figure who had been standing by the door all along. A well-fitted N95 respirator removes at least 95 per cent of airborne particles in testing, provided it seals against your face; a loose cloth mask does far less. Indoors, an air purifier with a HEPA filter, short for high-efficiency particulate air and a dense mesh that traps very small particles, does similar work. Keep windows shut on the worst days, skip the morning walk, and see a doctor if a cough lingers or breathing becomes difficult.

The intern asked for no promotion. It asked only to be worn.

SO, SHOULD YOU STOP EATING JAGGERY?

No, and the panel was gracious about it. Jaggery is a pleasant, traditional sweet, and a warm cup of jaggery tea on a grey morning is a comfort worth having. It is mostly sugar, so people with diabetes should count it as such, and it should not stand in for a mask or a doctor's visit. Remedies like this spread for good reasons: when the air outside is dangerous and the options are few, a small ritual feels like control.

The appraisal concluded that jaggery would remain on the team in its existing role, which is to be delicious. The post of Chief Lung Cleaner was awarded, unanimously and with no fanfare, to the cilia.

Radifah Kabir is a food and biotechnologist.

- Ends