'Just like we have accepted that more Indians have hypertension and diabetes, lower lung capacity of Indians should not be construed as normal.'
'We will see an epidemic of Chronic Obstructive Pulmonary Disease in India which is irreversible.'
'You will see that many of them are non-smokers while in the West, only smokers get COPD,' says Dr Anurag Agrawal.
Photograph: PTI. Kindly note the image is published only for representational purposes.
A study recently conducted by a team of scientists headed by Dr Anurag Agrawal, director, CSIR-Institute of Genomics and Integrative Biology, discovered that the lung capacity of Indians is 30% lower than North Americans or Europeans.
This makes Indians highly vulnerable to diabetes, heart attacks or strokes.
Dr Agarwal tells Rediff.com's Shobha Warrier what Indians should do to remain healthy.
What was the reason behind conducting a study on the lung capacity of Indians?
Lung function has been shown to vary between nations even if you are a person of the same height, weight and gender.
For example, in America, the lung function of a white is better than that of a black.
If you are a white European, your lung function is a as good as a white American.
And South Asians are the worst in the world.
Compared to an American of the same height, weight and gender, an Indian can blow out 30% less air after a full inspiration which is called the vital capacity of the lung.
Because Indians have 30% lower lung capacity, we have to establish what is normal for our country.
If your vital capacity is lower, you die faster. That's why we use the term vital capacity of the lung.
Even in America, studies have found that if a person has lower lung capacity, he dies much faster than a normal person, which is a decade earlier, of heart attacks, strokes and diabetes. Low lung function is also a reason for heart attacks.
You said lung capacity varies from whites to blacks to south Asians. Is it genetic?
If you take an Indian child born in America, his lung function is closer to an American than an Indian.
Does that mean more than genetic, external factors play a very important role?
It is more likely. There might be a small genetic component.
When you speak between nations, the poorer the country, the lower the lung function and higher the rate of dying due to heart diseases.
When you move to a richer country and your children are born there, their lung function capacity seems to be better.
So, clearly there are environmental factors.
Within the community, not everyone living in the same area has same lung capacity; some have better lung capacity and some poor and part of it could be genetic.
You said Indian children born in America have better lung capacity than those in India. But then, why is it that there is a difference between the whites and the blacks?
If you take the living conditions of the whites and the blacks, you will see that blacks are poorer than the white.
The poorer the country you are from, the earlier you die from poor lung capacity.
It is true that Africans have better lung capacity than Indians despite being poorer. So, there are more factors that determine the lung capacity of a person.
A little bit of it is genetic, but majority of the factors that contribute are external.
By external factors, do you mean air pollution?
In California, when they brought down pollution, the rate of increase of lung function among school children, improved.
So, we know that if we reduce pollution, lung growth becomes better.
One could conclude pollution is at least partly responsible for some of the reduction of lung growth of Indians.
But it is hard to say whether pollution is the most important reason.
What are the other external factors that affect lung capacity?
Lack of exercise, smoking, etc. Your heart becomes better when you exercise.
Basically, you have to demand something from the body for it to perform better.
So, reasons for poor lung capacity can be a sedentary lifestyle, lack of exercise and obesity.
And the third possibility could be nutrition.
It is not just the nutrition that a child gets matters, but what the mother eats when the child is inside the womb.
What is outside a person's control is the quality of the air he breathes.
Lastly, the genetic factor.
Studies have found that after three generations of living in America, whether you are a Japanese or a Scandinavian, you are almost the same height. So, the correct word is 'epigenetic'.
There might be small genetic epigenetic changes and the epigenetic part is mostly environmental.
In poor countries, people don't have the time to take very good care of their health and infections are common, they do not eat very nutritious food and the air quality is poorer.
Even if the air is clean, they tend to burn fuel inside their house, and thus the quality of air they breathe is poor.
Does that mean there will be a difference in the lung capacity of economically backward people living in poor areas and the affluent living in the cities?
There are some variations. In one study, they found that the lung function of children from Bangalore, is better than the lung function of children from outside Bangalore.
Bangalore is a rich Westernised city where the air is of good quality and everybody has electricity or LPG.
This may not be true for a city like Delhi where the air is very bad.
For the study I am conducting on the lung capacity of children around the country, we will measure as many factors that can be measured, and we will partition various factors like how much is due to air pollution, how much is due to nutrition, etc.
We will do the study involving all the ethnic groups in India to find the genetic aspect in lung capacity. We will try to explain as much of the variation we can.
What are the implications of the study that shows Indians have 30% lung capacity than Europeans and Americans?
My belief is that it will lead to heart attacks and lower life expectancy though this has not been proven at this point. Nobody has done a specific study on this. It is a general observation from America that those with low lung function die faster.
We have two possibilities. One is, we can assume the low lung function of Indians is normal, but it seems unlikely to me.
And the other is it is abnormal and it is abnormal to have low lung function and they die faster.
My hypothesis at the moment is, just like we have accepted that more Indians have hypertension and diabetes, lower lung capacity of Indians should not be construed as normal, but we should accept it as a problem.
Till now, studies are done on hypertension and diabetes, but no study was done connecting these two and lung capacity.
Two studies have found that Indians have low lung function and also high insulin resistance and high vascular diseases.
Until you measure all the three in the same person, you will not be able to know it for certain whether the three are interlinked. That is what my group is doing.
We already have the Western data which shows the more the insulin resistance, the lower the lung function.
What is the life expectancy of Indians compared to white Caucasians?
There is a difference of 10 years.
With the study, will you be able to connect lower life expectancy to low lung capacity, diabetes and heart diseases?
Yes, we believe so. These are caused by the same factor at the bottom.
It is not that low lung function is causing diabetes.
We believe that the many challenges of Indian life like indoor pollution, outdoor pollution, poor quality of nutrition, poverty, inadequate aerobic exercise and a sedentary lifestyle put together lead to changes in your body.
One of the earliest markers of which is insulin resistance.
Studies have shown that Indian children show insulin resistance even in their teens.
We have higher levels of sugar than our counterparts in the West. These molecular changes down the line probably lead to all the other problems like diabetes, cardiovascular diseases and poor lung function and strokes.
Several studies on diabetes among Indians have shown that Indians are more prone to diabetes because of the high body mass index. Is this due to external factors or genetic?
Most of it is due to external factors. The famous study by Dr Chattaranjan Yagnik showed that Indian babies are low in their birth weight, and they have more body fat and less muscles.
Indians adults also have more fat and less muscle compared to a Westerner and that changes many things.
We now know how to take care of diabetes and heart function. But if the lung function is poor, a person in their 60s and 70s becomes unfit.
In India, a 70 year old is very unfit compared to a Westerner. A 70 year old Indian can barely climb stairs and he walks very slowly.
The lungs are one of the organs which reaches the peak in the 20s and then there is a steady decline. This is for everyone wherever you are.
Another thing that is going to happen is, you will see an explosion of lung diseases in those in their 60s and 70s.
It means, we will see an epidemic of COPD (Chronic Obstructive Pulmonary Disease) which is irreversible.
You also will see that many of them are non-smokers while in the West, only smokers get COPD.
In India, you will see an epidemic of non-smoking COPD in the coming times.
Another unique thing about India is women are not taken care of like men.
If women are not healthy, children cannot be healthy.
The results of the study and what you are talking about are startling. What do you think Indians, both adults and children, should do?
To improve the health of the society, start from the simplest thing; take care of young girls so that they get nutritious food.
We must make sure that children must get plenty of exercise, cleaner air and also a good diet.
The adults should do breathing exercises though a study has to be done how much breathing exercises help improve lung function.
I personally believe that some of our traditional methods like yoga and breathing exercises can be helpful and useful. Even Sri Sri Ravishankar's Sudarshan Kriya concentrates on breathing.
Do you feel compared to Westerners, Indians do not exercise?
Absolutely. The minute we are richer, our attitude is to stop doing work.
And the poor people who are doing plenty of exercise don't have the nutrition and cleaner air. That is why all of us are suffering.
Do you think all developing countries go through this?
I believe all developing countries go through this, but smart wisdom lies in learning from the mistakes of others.
I think Bangalore is a good model for the rest of the country except its traffic.
By and large, the city has taken the best of both worlds and the main reason for this is education and some degree of economic improvement.
In general, the south of India is richer and less polluted while the rest of India is poorer and more polluted.
Does that mean the lung capacity of Indians living in the south can be better than those living in the north?
That will be an interesting area for a study.
If I look at the study done in Bangalore and other areas in north India, Bangalore is found to be much better.
So far, nobody has covered the entire India, but we will do it and by next year, we will have the results of the study.
Was the lung capacity of Indians better a decade or two ago?
Yes, data says it was better before.
A study done many years ago in Delhi shows that we were only 15% below the lung capacity of Americans or Europeans, but today, our lung capacity is 30% lower. Of course, it was different equipment, different people and different methods.
Studies done in America shows that it takes 15 years to get rid of these problems.
What the pollution level in Los Angeles in those days is comparable to what many Indian cities have today.
Of course, Delhi is worse.
What American cities were 15 years ago is what Bangalore is today.