While individual studies have given inconsistent results, the meta-analysis big picture suggests that air pollution plays a role in the increasing rates of childhood high blood pressure. With high blood pressure considered as one of the top ten contributors to global disease (1) public health went looking for answers, as these children with high blood pressure usually become adults with high blood pressure. In this case, finding root causes could allow more than a pound of preventive cure. Combining the pat individual studies into one big group revealed likely connections between high amounts of particulate pollution and rates of high blood pressure in children.
With 211.8 million disability adjusted life-years lost yearly (2) more medical clinicians and researchers have searched for explanations. We know that children can be more susceptible to the effects of toxins but past studies were not consistent in finding connections between toxins and blood pressure elevations. This group of researchers combined epidemiological studies to look for associations and found them. The data came from both children and adolescents in either China or European countries.
The three measures which resulted in the highest correlations to high blood pressure included particulate matter categories less than 2.5 micrometer and less than 10 micrometers as well as levels of nitrogen dioxide. They also considered whether the exposure was short term under 30 days, or long term over 30 days. Both long and short term exposure raised the risk of higher blood pressure in the studied children.
Negative health effects of air pollution should not be shocking discovery, but the effect on your children if they are breathing this bad air should rattle you at least a little. If that does not concern you, the global impact of disability across our economies as the health care costs raise should at least give you pause.
After these initial disconcerting considerations, one should next ask why some prior studies had not shown such correlations. In other words, why did some individual’s studies indicate that there was no risk while others showed risks? Why do we need a meta-analysis to give us a clearer answers. We expect clarity in science. We expect definitive answers so we can do something about what we find.
If only science were so clear all the time. A number of reasons exist for the ambiguity and seeming flip-flop between studies. These range from the outright deceptive studies in some cases where conflicts of interests or author biases pronounce a misleading results To the unintentionally erroneous from a poorly performed study. The former group may occur due to a researcher getting funds from a drug company or having an agenda to promote. Statistics can be manipulated to say just about anything. The latter group can arise when the methods to test something are not fine tuned or not designed adequately to answer the question at hand. Sometimes this is just inadequate design due to lack of funding or at other times, the question to be answered is not understaood well enough to design the study correctly the first time.
For the general public, exact answers are expected from science, but the reality is that science provides estimated answers which change as better studies are done or better understanding of the question develops. Anytime we grow dogmatic and claim a final answer to a given question, we risk falling from pride. In science, we must remain humble as the body of science grows and develops.
In functional medicine, we don’t let these uncertainties get in the way no more than we let the so called dogmas tie us down. We approach our patient’s conditions with humility that we can never have 100% of the helpful information about them or their present metabolic condition. We gather enough information about them and apply the available scientific knowledge to their situation so that we can proceed with a treatment plan likely to restore their health . We take science with a grain of salt, especially the dogmas. Helping patients live healthier more abundant lives means treating the patients in front of us and educating the public about the societal concerns like pollution and high blood pressure risks.
Miao Huang, Jingyuan Chen, Yiping Yang, Hong Yuan, Zhijun Huang, Yao Lu. Effects of Ambient Air Pollution on Blood Pressure Among Children and Adolescents: A Systematic Review and Meta‐Analysis. Journal of the American Heart Association, 2021; DOI: 10.1161/JAHA.120.017734
Thanks to Science Daily:
American Heart Association. “Air pollution linked to high blood pressure in children; other studies address air quality and the heart.” ScienceDaily. ScienceDaily, 4 May 2021. <www.sciencedaily.com/releases/2021/05/210504112554.htm>.
Secondary articles cited here:
- GBD 2015 Risk Factors Collaborators . Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016; 388:1659–1724. DOI: 10.1016/S0140‐6736(16)31679‐8.
- Kearney PM, Whelton M, Reynolds K, Muntner P, Whelton PK, He J. Global burden of hypertension: analysis of worldwide data. Lancet. 2005; 365:217–223. DOI: 10.1016/S0140‐6736(05)17741‐1.
Other Links between Pollution and Adverse Childhood effects or Hypertension
American Heart Association. “In-womb air pollution exposure associated with higher blood pressure in childhood.” ScienceDaily. ScienceDaily, 14 May 2018. <www.sciencedaily.com/releases/2018/05/180514083951.htm>.
American Heart Association. “High blood pressure linked to short-, long-term exposure to some air pollutants.” ScienceDaily. ScienceDaily, 31 May 2016. <www.sciencedaily.com/releases/2016/05/160531182419.htm>.
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.