Did you know that of all your organs, it is the lungs which are the first to age? Like the skin, they are exposed to the highest partial pressure of oxygen found in the body. And as we know, oxygen is a well-established factor in the ageing process.
All animals need oxygen to produce energy, but the mechanism involved is flawed: it leads to the formation of potentially toxic waste products called reactive oxygen species (ROS). ROS tend to alter all the cellular components they surround and thus a constant supply of antioxidant ‘weapons’ is needed to defend against them - antioxidants which are either produced by the body itself or ingested from the food we consume.
Unfortunately, we sometimes experience a temporary or more persistent surge in ROS numbers (in the case of infection, chronic disease, exposure to air pollution, or smoking, for example) and our antioxidant reserves become overwhelmed. It is precisely this imbalance
which enables ROS to attack surrounding tissue1
, and needless to say, lung tissue is first in the firing line. What’s more, airway epithelium is particularly vulnerable as antioxidant enzymes are poorly expressed in these cells2
Often, such imbalances are only temporary but when you put them all together, it’s clear that the long-term damage can mount up. And the greater the level of damage, the less effective our antioxidant defences become (since the ‘instructions’ for producing them become illegible) and the more the ageing process accelerates!
‘Normal’ ageing of the lungs begins at 30
What would happen if humans were exposed to an atmosphere composed only of oxygen?
Research has shown that lung damage develops rapidly in the alveolar-capillary membrane or blood-air barrier, and that it only takes 24 hours to trigger acute respiratory distress syndrome3
. This toxicity is mainly due to the generation of ROS at concentrations which exceed the body’s antioxidant capacity. These waste products cause overwhelming damage which triggers a severe inflammatory reaction.
At normal atmospheric concentrations, however, the damage caused is never that severe, as long as the body’s antioxidant systems work effectively to keep it to a minimum. But over the long-term, modest amounts of damage accumulate and become significant amounts: this is the ageing process in practice. Telomeres (associated with longevity) get shorter, repair mechanisms function less effectively, and antioxidant systems become defective, all of which exacerbates the effects of ageing. Lung tissue is less elastic and more permeable: from the age of 30, Forced expiratory volume in one second (FEV1) decreases by an average of 30ml per year, with the rate of decline accelerating over time4-5
. Maximum oxygen consumption falls from 45ml/min/kg at the age of 20 to 18ml/min/kg at the age of 80 (a decline of 60%) 6-7
These figures are dramatic but they don’t reflect reality. In actual fact, your lungs are rarely the same chronological age as you. A number of other factors influence this natural process, so much so that people of 35 can find themselves with a pair of ‘elderly’ lungs. Genetics clearly play a part, but by far the most important factors are air pollution (especially diesel particulates and ozone) and smoking8-9
: it’s estimated that there are four times the level of ROS in the lungs of elderly smokers as in those of elderly non-smokers2
. This is a significant difference which contributes to rapid ageing of the lungs, particularly since the antioxidant activity of alveolar macrophages declines over time as a result of smoking.
How can you slow the decline?
Apart from immediately quitting smoking, there are two key ways of holding back this unwelcome countdown: by being physically active and by ingesting antioxidants in order to neutralise ROS.
at any age plays a crucial role in maintaining and improving respiratory capacity. Anyone who decides to turn over a new leaf, stop being inactive and take up an age-appropriate sport will immediately improve their lung condition and slow down the decline. It must be said, however, that respiratory function sometimes declines to the extent that exercise is no longer possible or becomes too difficult. Such a state of affairs should be avoided at all costs in order to avoid falling into a downward spiral of accelerated ageing.
The other way of combatting ageing of the lungs is to increase your consumption of antioxidants
. A new study11
published in December 2017 shows that consuming at least three portions of fresh fruit a day, in particular tomatoes and apples, significantly slows down natural ageing of the lungs and helps repair existing damage to some degree. According to the study, benefits were even more marked in smokers and former smokers.
These findings are consistent with those of other scientists who have found that consumption of polyphenols and carotenoids, two major phytonutrient groups with antioxidant properties, is associated with better lung function and arrested pulmonary decline12-15
. This is hardly surprising when we know that these phytonutrients are antioxidants produced by plants to protect themselves against aggressors (insects, disease, UV rays), and are sufficiently attractive to incite animals to eat their fruits. Though there are many kinds of phytonutrients, the study suggests that the following two are particularly valuable in terms of protecting lung tissue:
- Flavonoids, a type of polyphenol. The researchers behind the above-mentioned study believe the benefits provided by apples are due to their flavonoid content. These antioxidant phytonutrients are found in various fruits, as well as in supplements such as Apple Polyphenols.
- Lycopene, a type of carotenoid. It is found abundantly in tomatoes which the study showed were most effective against respiratory decline. Lycopene supplements are available primarily to prevent disease and cellular ageing.
Research has also shown the importance of combining these antioxidants in order to benefit from their synergistic effects. In practice, this means eating a high proportion of fresh fruits and vegetables, although such scientific data is also used to formulate supplements such as AntiOxidant Synergy
which combines natural extracts with numerous polyphenols and carotenoids.
It is never too late then to fight this decline, especially when it affects such a vital activity as respiration. Good respiratory function is essential for maintaining moderate physical activity which affects almost all the body’s functions including quality of the immune response and longevity.
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