The answer might sound obvious to most people. If you live in a place where sweetened drinks are cheap, you’re going to encounter higher rates of obesity [1]. Living in food deserts increases the chance of getting heart disease [2]. Living in a place that encourages active commuting increases physical activity [3].
And what about how high you live?
The idea of living longer just because you’re living in higher elevations is simplistic.
Different diseases can cut the lifespan short. All of these can have different risk factors. Even within a single disease, the prognosis remains dynamic. The need of a person with stage II chronic kidney disease is very different from someone with dialysis-requiring end-stage renal disease.
Research on those living in higher elevations doesn't point to a single cause. More likely, it is a complex interaction of different factors that give these benefits. Or benefits to some diseases and drawbacks for others [4].
Every 1000m climb in your address reduces the mortality risk for coronary heart disease and stroke by 22% and 12%, respectively. Meanwhile, COPD has an increased mortality rate despite a lower overall prevalence. Other respiratory diseases such as pneumonia and influenza also show the same. On the other hand, living in higher elevations is seen as protective for some types of cancers. For the newer diseases such as COVID-19, the jury is still out on whether high altitude is truly protective [4,5,6 ].
That’s a lot of information to sift through. That alone doesn’t let people know where the regular Joe fits into this equation. For that, we need to understand the likely reasons behind the benefits of living at a high altitude and, conversely, potential drawbacks.
A high altitude environment favors the formation of a relatively high fitness level. Unlike cities closer to sea level, you’re less likely to find a convenience store every few meters. This could be the neighborhood’s gentle nudge towards more active commuting and, thus, more exercise.[3] It could also be because work at higher elevations demands more effort and energy [7].
The American Heart Association (AHA) recommends a certain amount of moderate and vigorous-intensity activities to achieve health benefits. Knowing whether an activity is light, moderate, or vigorous-intensity depends on the concept of metabolic equivalents or METs. This refers to how much energy is expended per weight of a person, with moderate being 3-6 METs and vigorous going above 6 METs [8]. At sea level and in an average person, the act of slowly walking home from a hard day’s work would be around 2 METs [9]. But if you’re walking uphill towards your lovely mountain home, it’s different. Even if it’s done slowly, the activity would require as much as 5-7 METs [4]. If the simple act of leisurely walking from one place to another generates that much effort, then meeting AHA’s recommendations should be easier when living in higher elevations.
High altitude living is good for those who want to train their hearts to be stronger. But this increased daily physical activity is not recommended for those who are already debilitated by even small amounts of exercise [4].
Congestive heart failure is a disease where the heart is not strong enough to pump blood properly through the body. Like a bad traffic jam, the blood backflows into the lungs. A person with this disease might find themselves gasping for air. The heart tries its best to pump properly when they try to walk to the bathroom on a normal day and elevation-- yet the wheezing and gasping persist. Moving to a higher altitude can exacerbate the already exhausted heart. This could spell disaster for areas where access to healthcare, because of the environment, is limited.
The heart is not the only thing that benefits from pre-conditioning.
See, the amount of oxygen in the air is the same, regardless of the altitude. However, there is a distinct difference in the pressure at higher elevations. This translates to less oxygen entering the lungs [9].
Stay with me here. This can be a good thing. It can have a preconditioning effect. Like a muscle being trained, these small amounts of stress can be protective against serious and protracted moments where oxygen is lacking [4].
It doesn’t even have to be a prolonged stay to get these benefits of living at a high altitude. Downhill skiing and overnight stays have also shown similar adaptive mechanisms. In case you needed another excuse to vacation in the mountains [4].
But this pre-conditioning is not for everyone.
As I said, chronic obstructive pulmonary disease (COPD) and higher elevation don’t mix particularly well. COPD is a disease where the air sacs in the lungs have been destroyed by cigarette smoke. Part of the recent treatment for this disease is the supplemental use of oxygen. When there’s a lack of oxygen, the blood vessels going into the lungs can build up the pressure-- making it harder for oxygen to pass into the body. This is a normal protective effect that forces the gas exchange to occur in the better air sacs of the lungs. But in lungs with already extensive damage, this could be the tipping point where a person ends up gasping for air as he cannot fully inhale [4].
There are still some diseases where different researchers have come up with different answers. Some cancers have a higher incidence in higher elevations [10] while others have much lower ones [4]. Even melanoma, something you’d think would be more prevalent when you’re living closer to the sun, doesn’t follow our simple logic. Vitamin D, UV radiation, and the mountain air all confer different degrees of protective benefits.
So soon after the start of the COVID-19 pandemic, we still don’t have surefire answers on what the environment does for the disease. Is it the lower population density in higher elevations that seem protective of COVID-19? Is it that low rates of cardiovascular disease, one of COVID-19’s most serious comorbidities, also beget low mortality rates? Is it even consistent among the research-- with only a year’s worth of it, it’s hard to say [6].
And even where we’re sure of the answer, it can still boil down to “It depends.” Living in higher elevations can be a good thing when you’re healthy, without debilitating heart disease, and want to keep it that way. When you already have a chronic lung disease and the balance of oxygen is more delicate, it’s another matter.
These are lesser-known points to consider when figuring out if you’re up for living the high life.
