Oxygen is essential for human life. That is well known. However, the level of Oxygen in the atmosphere has interesting effects.
I wrote previously about The Hypoxia Inducible Factor (HIF). HIF (particularly 1 alpha) is a molecule which signals cells to create proteins to build in response to stress. This can involve building new mitochondria or recycling old inefficient mitochondria. In essence it is ringing an alarm that calls for cells to get better prepared for stress. Interestingly HIF is switched on by a drop in the oxygen partial pressure (that proportion of air pressure that is oxygen).
It is also well known that if brain cells get too little Oxygen then they can get harmed or die. Hence too low an Oxygen level causes brain damage. In fact there is evidence from people living at high altitudes that at a point the oxygen level is too low and this harms health.
However, there is another aspect of Oxygen levels that relates to the mitochondria. The mitochondria produce energy mainly in the form of ATP, but they also generate what are called "Reactive Oxygen Species" (ROS) whilst doing so. These ROS can cause harm to the mitochondrial DNA and that can make the mitochondria less efficient. I think this is the cause of development and aging. One point about Oxygen and Mitochondria is that the higher the partial pressure of Oxygen then the higher the levels of ROS.
Hence we have from this the idea that as people live in lower levels of oxygen they should develop and age more slowly although once the oxygen levels get too low this will be harmful to health. So we can look at what research there is for this to be true.
Looking at the papers from which the abstracts are below there appears to be contradictory evidence on menarch and menopause. However, that is because other factors will have an effect. However, the evidence on mortality does seem consistent with a reduction in aging diseases not related to breathing although unsurprisingly COPD is more likely. A report on Parkinsons Disease is included because that appears also to be related to mitochondrial harm.
A reasonable conclusion is that living at a lower than 21% Oxygen would probably result in slower development, but there clearly is a point at which low Oxygen levels are harmful.
Here are the papers:
The International Menopause Study of Climate, Altitude, Temperature (IMS-CAT) and vasomotor symptoms In this study of Spanish-speaking women, those living in countries with higher temperatures and lower altitudes reported more frequent and problematic hot flushes.
Menopause and High Altitude: A Scoping Review—UIAA Medical Commission Recommendations Women living at high altitude experience an earlier onset of menopause compared with women living at sea level (Beall, 1983; Gonzales and Gonez, 2000; Gonzales and Villena, 2000). The median age of onset of menopause at high altitude ranges from 45.3 to 48.0 years, while median age at low altitude is 48.8 years (46–52 years) (Beall, 1983; Gonzales and Gonez, 2000; Gonzales and Villena, 2000; Kapoor and Kapoor, 1986; Schoenaker et al., 2014; Wood et al., 1985). One multicenter study on women living at high elevations compared with lowlanders reported that women living at higher altitudes had less frequent and less distressing hot flashes, and considered them less problematic and less interfering with their daily life based on a validated rating scale (Hunter et al., 2013).
The effects of high altitude on age at menarche and menopause The age at menarche and menopause of three groups of Bhotia females living at high altitude, Himalayan region — Uttar Pradesh, North India, were studied. The Johari Bhotia women had earliest menarche (¯X=15.1±1.1 years) as compared to Rang Bhotias, settled (¯X=15.6±0.9 years) and Rang Bhotias, migratory (¯X=16.0±1.0 years). The differences between all these three groups for age at menarche were significant. A trend towards increase in age at menarche with an increase in altitude has been observed, but the total fertility period in the three groups remained similar as early menarche has been found to be associated with early onset of menopause and late menarche with late menopause.
The effect of altitude on adolescent growth development To evaluate the effect of altitude on adolescent growth and development, three groups of healthy, well-nourished youth of similar socioeconomic status and ethnic grouping who resided at sea level (n = 1262 subjects), mid-altitude (n = 1743 subjects), and high altitude (n = 1137 subjects) were studied. The following parameters were evaluated: weight and height in all subjects; genital and pubic hair development in the males; and the initiation of breast development and age of menarche in the females. At mid-altitude, puberty appears to start at a similar age, but lasts longer, than at sea level. At high altitude, puberty starts significantly later and is more prolonged than at sea level and mid-altitude. Our data reveal relatively little effect of altitude upon growth and weight-gain patterns or final attained heights and weights.
Effects of Living at Higher Altitudes on Mortality: A Narrative Review Beside genetic and life-style characteristics environmental factors may profoundly influence mortality and life expectancy. The high altitude climate comprises a set of conditions bearing the potential of modifying morbidity and mortality of approximately 400 million people who are permanently residing at elevations above 1500 meters. However, epidemiological data on the effects of high altitude living on mortality from major diseases are inconsistent probably due to differences in ethnicity, behavioral factors and the complex interactions with environmental conditions. The available data indicate that residency at higher altitudes are associated with lower mortality from cardiovascular diseases, stroke and certain types of cancer. In contrast mortality from COPD and probably also from lower respiratory tract infections is rather elevated. It may be argued that moderate altitudes are more protective than high or even very high altitudes. Whereas living at higher elevations may frequently protect from development of diseases, it could adversely affect mortality when diseases progress. Corroborating and expanding these findings would be helpful for optimization of medical care and disease management in the aging residents of higher altitudes.
Exploring the Effect of Altitude on Parkinson's Disease There is a lot of anecdotal evidence that the symptoms of Parkinson's disease (PD) may improve markedly during visits to high-altitude destinations. Given the significant, but as yet anecdotal evidence, it is necessary to further explore this interesting phenomenon, using a systematic research approach.
I wrote previously about The Hypoxia Inducible Factor (HIF). HIF (particularly 1 alpha) is a molecule which signals cells to create proteins to build in response to stress. This can involve building new mitochondria or recycling old inefficient mitochondria. In essence it is ringing an alarm that calls for cells to get better prepared for stress. Interestingly HIF is switched on by a drop in the oxygen partial pressure (that proportion of air pressure that is oxygen).
It is also well known that if brain cells get too little Oxygen then they can get harmed or die. Hence too low an Oxygen level causes brain damage. In fact there is evidence from people living at high altitudes that at a point the oxygen level is too low and this harms health.
However, there is another aspect of Oxygen levels that relates to the mitochondria. The mitochondria produce energy mainly in the form of ATP, but they also generate what are called "Reactive Oxygen Species" (ROS) whilst doing so. These ROS can cause harm to the mitochondrial DNA and that can make the mitochondria less efficient. I think this is the cause of development and aging. One point about Oxygen and Mitochondria is that the higher the partial pressure of Oxygen then the higher the levels of ROS.
Hence we have from this the idea that as people live in lower levels of oxygen they should develop and age more slowly although once the oxygen levels get too low this will be harmful to health. So we can look at what research there is for this to be true.
Looking at the papers from which the abstracts are below there appears to be contradictory evidence on menarch and menopause. However, that is because other factors will have an effect. However, the evidence on mortality does seem consistent with a reduction in aging diseases not related to breathing although unsurprisingly COPD is more likely. A report on Parkinsons Disease is included because that appears also to be related to mitochondrial harm.
A reasonable conclusion is that living at a lower than 21% Oxygen would probably result in slower development, but there clearly is a point at which low Oxygen levels are harmful.
Here are the papers:
The International Menopause Study of Climate, Altitude, Temperature (IMS-CAT) and vasomotor symptoms In this study of Spanish-speaking women, those living in countries with higher temperatures and lower altitudes reported more frequent and problematic hot flushes.
Menopause and High Altitude: A Scoping Review—UIAA Medical Commission Recommendations Women living at high altitude experience an earlier onset of menopause compared with women living at sea level (Beall, 1983; Gonzales and Gonez, 2000; Gonzales and Villena, 2000). The median age of onset of menopause at high altitude ranges from 45.3 to 48.0 years, while median age at low altitude is 48.8 years (46–52 years) (Beall, 1983; Gonzales and Gonez, 2000; Gonzales and Villena, 2000; Kapoor and Kapoor, 1986; Schoenaker et al., 2014; Wood et al., 1985). One multicenter study on women living at high elevations compared with lowlanders reported that women living at higher altitudes had less frequent and less distressing hot flashes, and considered them less problematic and less interfering with their daily life based on a validated rating scale (Hunter et al., 2013).
The effects of high altitude on age at menarche and menopause The age at menarche and menopause of three groups of Bhotia females living at high altitude, Himalayan region — Uttar Pradesh, North India, were studied. The Johari Bhotia women had earliest menarche (¯X=15.1±1.1 years) as compared to Rang Bhotias, settled (¯X=15.6±0.9 years) and Rang Bhotias, migratory (¯X=16.0±1.0 years). The differences between all these three groups for age at menarche were significant. A trend towards increase in age at menarche with an increase in altitude has been observed, but the total fertility period in the three groups remained similar as early menarche has been found to be associated with early onset of menopause and late menarche with late menopause.
The effect of altitude on adolescent growth development To evaluate the effect of altitude on adolescent growth and development, three groups of healthy, well-nourished youth of similar socioeconomic status and ethnic grouping who resided at sea level (n = 1262 subjects), mid-altitude (n = 1743 subjects), and high altitude (n = 1137 subjects) were studied. The following parameters were evaluated: weight and height in all subjects; genital and pubic hair development in the males; and the initiation of breast development and age of menarche in the females. At mid-altitude, puberty appears to start at a similar age, but lasts longer, than at sea level. At high altitude, puberty starts significantly later and is more prolonged than at sea level and mid-altitude. Our data reveal relatively little effect of altitude upon growth and weight-gain patterns or final attained heights and weights.
Effects of Living at Higher Altitudes on Mortality: A Narrative Review Beside genetic and life-style characteristics environmental factors may profoundly influence mortality and life expectancy. The high altitude climate comprises a set of conditions bearing the potential of modifying morbidity and mortality of approximately 400 million people who are permanently residing at elevations above 1500 meters. However, epidemiological data on the effects of high altitude living on mortality from major diseases are inconsistent probably due to differences in ethnicity, behavioral factors and the complex interactions with environmental conditions. The available data indicate that residency at higher altitudes are associated with lower mortality from cardiovascular diseases, stroke and certain types of cancer. In contrast mortality from COPD and probably also from lower respiratory tract infections is rather elevated. It may be argued that moderate altitudes are more protective than high or even very high altitudes. Whereas living at higher elevations may frequently protect from development of diseases, it could adversely affect mortality when diseases progress. Corroborating and expanding these findings would be helpful for optimization of medical care and disease management in the aging residents of higher altitudes.
Exploring the Effect of Altitude on Parkinson's Disease There is a lot of anecdotal evidence that the symptoms of Parkinson's disease (PD) may improve markedly during visits to high-altitude destinations. Given the significant, but as yet anecdotal evidence, it is necessary to further explore this interesting phenomenon, using a systematic research approach.
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