Lung regeneration can occur in adults, defying previous belief (NEJM)
Nov 142012
New Lung Tissue Growth Discovered: Is Some Lung Regeneration Possible?

Lung regeneration has never been thought possible in adults. But Steven Mentzer et al from Brigham and Women's at Harvard reported a case of a 33 year old woman who had an apparent 64% increase in the number of functioning alveoli in her left lung, during 15 year follow-up after a right pneumonectomy in 1995 for adenocarcinoma (despite her young age, she had a 30+ pack-year smoking history).

Although existing lung parenchymal tissue was known to expand after lung resection, in adults this was thought to occur through dilation of existing alveoli and supporting tissues, not de novo growth of new alveoli. However, experiments in dogs suggested lung regeneration was possible, and so researchers turned their attention to closely following this patient and her lung function after her surgery.

The woman described had an initial FEV1 of 35% and FVC of 49% after pneumonectomy. But for 15 years, steady improvements in her spirometry resulted in a final FEV1 of 60% and FVC of 73%. (According to expectations, she should have had about a 10% decline over 15 years, due to aging.) Her left lung grew larger and larger on annual surveillance CT scans, partially herniating into the right hemithorax.

The authors used experimental MRI scan techniques (diffusion of inhaled hyperpolarized helium-3 gas) to determine alveolar dimensions. Larger alveoli look different than smaller alveoli with this technique, owing to differences in "clumping" of concentrated gas molecules.

The authors speculated that the woman's young age at the time of surgery and active lifestyle with vigorous exercise including cycling, walking, and yoga in the years following surgery may have contributed to the growth of lung tissue, saying:

"We hypothesize that, reminiscent of the role of stretch in lung development, cyclic stretch as such may be an important trigger for new lung growth. Regardless of the specific mechanism, the findings in this patient support the concept that new lung growth can occur in adult humans."

James P. Butler et al. Evidence for Adult Lung Growth in Humans. NEJM 2012; 367:244-247.

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  14 Responses to “New lung tissue growth can occur in adults, defying previous belief”

  1. Very interesting reading indeed, raises possibilities of future productive studies for the treatment of lung diseases.

  2. I will show this to my patients. It will be another prop to show what a healthier lifestyle and VIGOROUS exercise can do to improve vitality.

  3. I am a patient who has walked an hour a day since 1997
    I had a right lung transplant in 2000
    Please indicate how vigorous exercise is required to improve vitality

  4. pavel, thanks for your comment here; I am starting a yoga class on Tuesday and also have been doing an arm bike for several years (it sits on a table in my home). ron

  5. My spirometry tests of 2009 were FEV1 of 37% and FVC of 48%. I began using a cardio exercise system known as VO2MAX. Following the system, I not only feel better and am able to use oxygen more efficiently, but I have also increased my spirometry numbers, year after year. My most recent was FEV1 of 52% and FVC of 65%. I am 52 yrs of age, so I should have seen a progressive decline of 4 – 8% in lung function instead of the increases. I take my body to its limits when doing cardio, and had extensive cardio workups, including stress tests before starting this. Initially, my doctor told me not to exercise so much, but he has witnessed the improvement of my lung function, and has begun asking me about the specific techniques I use. I simple refused to believe that my lungs wouldn’t regenerate, and did everything I could, to “heal” myself. I began exercising just to feel better and to withstand the periodic bouts called “exacerbations” that so frequently kill people with lung conditions. My improvements are related to 3 things: 1) Positive mindset 2) Diet and supplements (exercise creates tons of free-radicals in your body) and 3) Using VO2MAX to build my cardio endurance.

    I was only able to do little more than walk, when I started, and I was obese, in addition to my lung problems. My doctors held out little hope that I would be able to improve my health but said I might be able to improve my quality of life from exercise.

    • wow, good for you Kevin. My husband is in his 3rd yr of Pulmonary Fibrosis. The disease has been stable until this past yr where he has suffered a significant decline in lung function. He is still able to excercise and he too says it makes him feel alot better. Staying active and pushing the exercising of the lungs has to do some good.
      What supplements are you taking?

      • I take resvertrol, (by way of a glass of red wine in the evening), a multi-vitamin, vitamin E, Inositol, and Broccoli sprout extract (for sulphoraphane). I eat extremely well, usually fresh greens (spinach salads, instead of lettuce) some carbs, usually by way of wild rice, limited proteins, but I usually make a smoothy in the morning with fruits, protein powder, and whatever I seem to have laying around that is healthy and will taste decent in my smoothy. I like grapes, berries, and nuts of all kinds.

        • Do you know any one with COPD who was able to significantly improve lung function just like you did ?

          • No I don’t, I was actually thrilled to find this abstract of someone having improved lung function, because I was told it was impossible. Lungs aren’t supposed to regenerate, so I thought perhaps I was losing my mind, or I didn’t measure my spirometry in earlier tests, but it seems to improve each time, and I am careful having it done on the same machine, and by the same pulmonologist. He is fascinated by it as well.

    • Kevin,

      I am pleased to learn there is someone else who does not accept that lungs can not be regenerated!

      I have been trying to do so for over 20 years by walking for long times at relatively low intensities.

      Now I understand I must bump up the intensity of my exercise and perhaps try VO2MAX.

      Could you be so kind as to steer me to where I can learn more about your exercise program that has been effective for you in regenerating your lungs.

      Thanks for giving hope to all of us who desire to regenerate our lungs!


      • Ron,
        There are many sources, but essentially you can learn about it on wikipedia. It is a method which gives you a reading of how fit you are, to start out with. It is done by bringing your heart rate into a particular zone. Let me start with the caveat that you need to talk with your doctor to find out if you are physically capable of taking your body to extremes. First, and this is for men, you need to calculate your maximum heart rate. This is done by the formula: 220 – (your age in years) I am 52, so my maximum Heart Rate (HR from here on) is 220 – 52 which comes out to 168, In VO2Max, you want to exercise and keep your heart rate greater than about 85% of your maximum heart rate. So for me that would be 168 x 0.85 = 142.8 or 143 bpm.

        It will take some time for you to get in this range, and don’t sweat it. This can be a very dangerous exercise regimen for people who don’t recognize their limitations. So, I will have a 5 minute warm-up period on an eliptical machine, and slowly increase resistance on the machine until I can get my HR up to 143, give or take a couple of beats. and hold it there for 40 minutes, then a 5 minute cool down period. I do this cardio every day, and twice a week I get my heart rate above 90% of my maximum HR. I shoot for twice a week, but if I’m not feeling up to it, I don’t go there. On a rare occaision, I don’t even feel like going to 85%, so I do what I can. I might take off 5 nights a year, owing to various reasons.

        I can’t stress it enough about being very careful, and involving your doctor in this. I talked with my doctor who said that physically I could probably do it, but he though that it was working too hard and that I should just accept that my lungs were going to degenerate over time, and that perhaps I ought to take it easy and accept my fate. He didn’t recommend I not exercise, just not with such intensity. Obviously, I rejected his advice on the intensity. It reminds me of a story about my uncle. He had 6 kids, and had the classic surburban life, nice wife, nice house, nice cars, nice kids, but he was a bit overweight and worked a desk job. He exercised infrequently. One day, he didn’t feel that good, and decided it might be time to exercise when he felt a little better. A few days later he went for a jog. He returned home, and got a glass of water and sat in his easy chair. When he went to stand up, after sitting for a half hour, he had a massive heart attack. He survived for a day or so in the hospital, but then died. The point is, its easier than you think to kill yourself with exercise if you aren’t very careful and work up to what you want to do. It took me almost two months before I could work above 85% for 40 minutes, and another month before I could get above 90% on two days a week. There are millions of resources all over the internet, and good luck!

        • hi kevin and thanks for your help above
          I have today been able to work out for 40 minutes at 80% of my maximum heart rate
          warmed up for 10 minutes and cooled down for 10
          I am using a treadmill to do so; adjusting the slope up to raise my heart rate
          I have my pulmonologist involved who had me do a six minute walk yesterday
          he will do another in 3 months to see how it is going
          it is my goal to put up this info on a website so many can see how it is going
          so far, I started a blog ( but can no longer post there
          something about my browser in not right?

  6. I am greatly encouraged to hear of people who accept the possibility of lung tissue regeneration.

    COPD ( emphysema) diagnosed approx 13 years ago, led to a hospitalised experience to treat an exacerbation 8 months ago.

    The treating doctor advised that breathing exercises, consisting of belly breathing and expiring through pursed lips, would help me, but I probably wouldn’t experience any benefit in the short term, perhaps even a month or more.

    I subsequently commenced the exercise and I have to say that I noticed an improvement within three days..!

    I had heard of this exercise but never really adopted it on a regular basis.

    I persevered, really pushing myself, to such an extent that my chest became sore with the unaccustomed exercise.

    The net result has been such that my lung physician, extended my previously frequent appointments, to six months, and he would decide on my next visit whether to stretch this out to 12 monthly appointments.( I,m due to see him next month)

    I am 72 years old and have cardiac issues which have precluded me from physical exercises.

    I take numerous supplements, but I think it would be wishful thinking to think that I,m experiencing regeneration but nevertheless I do do feel so much better.