How mandatory common salt iodisation helped bring down thyroid disorders

My grandmother was in her 60s when she developed goitre — an abnormal and visible swelling in the neck caused by an enlarged thyroid gland. It was a result of iodine deficiency in her diet, we were told, and she had to be operated for it. This was in the late 1980s. A high incidence of thyroid-related disorders such as hers, which were linked to iodine deficiency in the population, had earlier in the decade prompted the Congress government at the Centre to make iodisation of common salt compulsory in the country.

In the years to come, this move would be repeatedly debated and once was even challenged by the Swadeshi Jagran Manch during the tenure of Atal Bihari Vajpayee’s government in 2000. The Rashtriya Swayamsevak Sangh-affiliated outfit even announced plans to carry out a “Dandi March” against the ban on sale of non-iodised common salt for human consumption, arguing that iodised salt cost three times as much as ordinary salt. But governments have consistently shown a commitment to pushing iodised common salt in the country with the aim of dealing with a wide spectrum of thyroid-related problems that are known to cause goitre, low IQ, mental retardation, neuromotor defects, birth defects, abortions and still births.

Despite this, 42 million people in India still suffer from thyroid diseases. And of all thyroid disorders, hypothyroidism — in which the thyroid gland does not produce enough thyroid hormone — remains the most common. One in every 10 Indians (the majority being women) today suffers from it. 
 

The thyroid hormone is critical for the body as it controls our metabolism — our breathing, heart rate, body weight, nervous system, cholesterol levels, muscle strength, menstrual cycles, and a lot more.

Around me, a colleague in her late 20s suffers from it. A neighbour in her 30s has just been diagnosed with it. And a relative in her early 40s has just found out during her routine annual medical tests that the fatigue, weight gain, hair loss and insomnia that she was experiencing were a result of hypothyroidism. The problem has clearly only been partly corrected in all these decades of active iodisation.

“Well, iodisation has helped in that we now do not see as many cases of severe thyroid-related problems such as endemic goitre. Cases of congenital disorders, too, have reduced,” says Ajay Kumar Ajmani, senior consulting endocrinologist at BLK Super Speciality Hospital, New Delhi. 

This proactive public health measure, say doctors, has helped prevent not only general thyroid disorders, but also endemic cretinism, a disorder that affects a newborn’s brain.

Despite correction of iodine deficiency, hypothyroidism remains an important public health problem. “The reason for its high prevalence is not known,” says Ambika Gopalakrishnan Unnikrishnan, CEO and chief of endocrinology at the Chellaram Diabetes Institute, Pune. With universal salt iodisation, while the role of iodine deficiency as a cause of hypothyroidism has been largely overcome, now thyroid autoimmunity is probably becoming an important contributor, says the doctor who has been researching the subject.

Some experts have in the past said that India’s transition from iodine-deficient to iodine-replete status has been followed by a spurt in autoimmune thyroid disorders. Concerned about any incorrect interpretation of this statement, Unnikrishnan says, “There is no evidence to establish the connection between iodine supplementation and autoimmune hypothyroidism. Further research is needed to understand why autoimmune hypothyroidism is common.”

He says that while there is some evidence to suggest that environmental factors may be a contributor to abnormal thyroid health, however, we do not know if these are major factors. “Some of the scientific evidence comes from studies on animals, which cannot be extrapolated to humans.”

There are, however, those who are convinced that our environment and lifestyle are contributing to poor thyroid health.

Shikha Sharma, physician and founder of Nutri-Health, a Delhi-based platform that offers health and diet management programmes, blames it on high levels of chemical pollution in the air, water and food. “Anything and everything is highly dosed with preservatives,” she says. “Plastic, which is freely dumped, is destroying our soil quality and our factories are spewing toxins into river waters.” There is no government policy on how our national assets — rivers and agricultural land — should be managed, she says. And while universal iodisation has helped, it continues to be an oversimplified solution to a compelling health concern, she adds.

Sharma is also not a big fan of water purifiers that use the reverse osmosis (RO) technology. “RO purifiers do not keep the vitality of the water intact. They are not a healthy option,” she maintains. “Instead one should choose a good purifier that retains the water’s mineral content and the ideal PH level.”

She also lists high levels of stress as a contributing factor. “We are constantly pushing our body to react to our surroundings and not allowing it any time to rejuvenate.” Hypothyroidism, she adds, is one of the fallouts of this compromised lifestyle.

Hypothyroidism can be easily diagnosed by a blood test and treated by correcting thyroid hormone deficiency by oral pills that contain the hormone. But is the condition reversible? “There is some evidence that some cases of subclinical hypothyroidism (a mild form of hypothyroidism) may reverse spontaneously, but the reasons are yet to be studied,” says Unnikrishnan.

Those with any form of hypothyroidism need to regularly monitor their thyroid function tests. New research suggests that not all forms of hypothyroidism need treatment, says Unnikrishnan. “Only special groups of subclinical hypothyroidism need treatment — for example, those with symptoms or with highly abnormal thyroid function tests, young persons and pregnant women.”

He says a new guideline (BMJ Rapid Recommendations guide published in The BMJ) published two weeks ago suggests that many cases of subclinical hypothyroidism do not need therapy at all. “In general, it is better to avoid giving thyroid hormones to people with mild hypothyroidism or subclinical hypothyroidism, unless there are compelling indications.”

It is also well known that some cases of subclinical hypothyroidism may improve spontaneously, he adds. “It is important to re-test in case of doubt and give treatment to only those who need it.”

Sharma is of the view that if India is to deal with thyroid disorders, then the government needs to think beyond just compulsory iodisation. “A holistic approach — a strong policy — is needed that involves improving the health of our environment, land and water.”

Germany has a “green” political party, Alliance 90/The Greens, which focuses on ecological, economic, and social sustainability. It even wins elections. In the 2019 European Parliament election, the Greens, as they are called, drew 20.5 per cent of the votes and won 20 seats in the national election — their best result to date. India could most certainly draw a lesson from them.