The Power of Nutrition (Part 2): The Global Burden of Non-Communicable Diseases

The world of health care has seen some tremendous changes within the last few decades. Through measures of public health, vaccinations, and antibiotic and antiviral drugs, deaths caused by infectious diseases are declining steadily. Ground breaking, basic research and the current development of new treatment strategies let us successfully tackle more and more diseases, among them rare and genetic conditions. Also modern drugs and techniques enable people, at least in high income countries, to live longer despite their suffering from chronic illnesses.

However, there is another truth behind those remarkable achievements: Infectious diseases are not gone; in fact, they are declining only quite slowly. Increasing antibiotic resistances, the lack of new antibiotic substances, and the existing threat of new epidemics make it quite clear that ever evolving pathogens can only be controlled with constant efforts and investments. The lack of knowledge regarding many diseases, among them rare ones like ALS and common ones like Alzheimer’s, is still huge. Furthermore, some of the drugs targeting chronic illnesses might slow down their progression, but they cannot reverse them, making it difficult and frustrating for patients and health professionals to cope with these diseases.

Among these circumstances, the status of chronic diseases, or non-communicable diseases, is of special interest, as they seem to demand huge capacities of entire health care systems and individual health professionals alike.

Rescue Chopper

What Kills and Harms Most

Non-communicable diseases are chronic diseases, such as heart disease, cancer, diabetes, chronic kidney disease, or chronic respiratory disease. The extent to which NCDs influence human health globally and regionally is quite dramatic. Of the 55 million global premature deaths in 2013, a staggering 38.3 million – that’s 70% – have been attributable to NCDs. Just a few decades ago in 1990, that number was down at 57% 1)GBD 2013 Mortality and Causes of Death Collaborators. Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990e2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 2015;385:117–71.. Out of the top ten causes of deaths in high income countries, nine are now non-communicable diseases. Middle- and low-income countries are hit especially hard, as 85% of NCD-deaths 2)Global Health Estimates 2016: Deaths by Cause, Age, Sex, by Country and by Region, 2000-2016. Geneva, World Health Organization; 2018. occur in those countries , whose health care systems have been under pressure all along due to ever present infectious diseases and chronic underfunding.

A more accurate measure of disease burden than just numbers of deaths are “Disability Adjusted Life Years” (DALYs). As they express the number of years lost due to ill-health, disability and early death, one DALY can be thought of as one lost year of “healthy” life. The sum of DALYs across the population are a measurement of the gap between current health status and an ideal health situation. Fifty percent of the global DALYs are caused by non-communicable diseases 3)Murray CJL, Vos T, Lozano R, Naghavi M, Flaxman AD, Michaud C, Ezzati M, et al. (2012): Disability-Adjusted Life Years (DALYs) for 291 Diseases and Injuries in 21 Regions, 1990–2010: A Systematic Analysis for the Global Burden of Disease Study 2010. The Lancet 380,9859: 2197–2223.. When NCDs are considered as one entity -as they are mainly induced by the same risk factors – they are by far the biggest issue that patients, families, communities, and health care systems have to cope with.

The number one killer among non-communicable diseases, and thus the number one killer worldwide, are cardiovascular diseases (CVD). They accounted for one third of all global deaths in 2015. While CVD prevalence  and mortality declined slowly since 1990 in some high income countries, most likely due to their well-funded health care systems and their ability to treat CVD more effectively, these trends have plateaued 4)Roth GA, Johnson C, Abajobir A, et al. Global, Regional, and National Burden of Cardiovascular Diseases for 10 Causes, 1990 to 2015. J Am Coll Cardiol. 2017;70(1):1-25. on the current high level. With the increase of diabetes and obesity worldwide, these trends could even rise again.  The focus on treatment with (new) drugs and (high tech) medical procedures in the fight against cardiovascular and other non-communicable diseases leads to another burden for communities: costs.

What Costs Most

What_costs_us_mostNext to the deteriorating effect that NCDs have on people’s health and their life quality, they are also a major economic concern and have serious financial implications for our health systems.

During the next 20 years up to the year 2040, it is estimated that global spending on health will increase from 9 trillion dollars to 24 trillion dollars per year 5)Dieleman, JL, Campbell M, Chapin A, Eldrenkamp E, Fan VY, Haakenstad A, Kates J, et al. (2017): “Future and Potential Spending on Health 2015–40: Development Assistance for Health, and Government, Prepaid Private, and out-of-Pocket Health Spending in 184 Countries.” The Lancet 389,10083;2005–30.. The NCDs share of these health expenditures is estimated to be at least 60% on average in OECD countries 6)Focus on Health Spending, OECD Health 2016, https://www.oecd.org/health/Expenditure-by-disease-age-and-gender-FOCUS-April2016.pdf, reaching as high as 90% in the USA (when mental illnesses are included) 7)Buttorff C, Ruder T, Bauman M. Multiple Chronic Conditions in the United States[PDF – 392 KB]. Santa Monica, CA: Rand Corp.; 2017..

To get an idea of the real costs of NCDs, the estimated productivity losses need to be added to the mere health expenditures. In 2011, the World Economic Forum and the Harvard School of Public Health projected the total lost output in 169 countries over the period 2011- 2030 from the four largest NCDs (cardiovascular diseases, cancer, chronic respiratory diseases, diabetes) and mental health conditions to be nearly 47 trillion dollars. Furthermore, they expect the cumulative NCD losses to rise steadily with a soaring increase of this rate by 2030 8)Bloom, D.E., Cafiero, E.T., Jané-Llopis, E., Abrahams-Gessel, S., Bloom, L.R., Fathima, S., Feigl, A.B., Gaziano, T., Mowafi, M., Pandya, A., Prettner, K., Rosenberg, L., Seligman, B., Stein, A.Z., & Weinstein, C. (2011). The Global Economic Burden of Non-communicable Diseases. Geneva: World Economic Forum. .

The aforementioned biggest killer, cardiovascular diseases, alone costs the economy of the European Union  210 billion Euros ( around 240 billion dollars) per year 9)Wilkins E, Wilson L, Wickramasinghe K, Bhatnagar P, Leal J, Luengo-Fernandez R, Burns R, Rayner M, Townsend N (2017). European Cardiovascular Disease Statistics 2017. European Heart Network, Brussels. , which is, for example, one third of the amount, the EU is spending on education each year 10)Eurostat online: https://ec.europa.eu/eurostat/web/products-eurostat-news/-/DDN-20170828-1.

So quite plausibly, the diseases causing the most deaths and the most ‘healthy life years lost’, generate the lion’s share of our healthcare expenditures and lost economic output as well. To tackle these diseases successfully is hence the most effective way to reduce deaths, suffering, and the burden of exploding health care costs for communities all around the world. The task of tackling them successfully leads to their root causes.

The Roots of All Evil

Numerous studies have identified risk factors for the development of non-communicable diseases, and some have been found to be culprits universally around the world and simultaneously in different NCDs with high disease burden. The most comprehensive project to discover the global causes of death, disability, and the corresponding risk factors is the ‘Global Burden of Disease’ (GBD). Collected and analyzed by a consortium of more than 3,600 researchers in more than 145 countries, the data capture premature death and disability from more than 350 diseases and injuries in 195 countries, by age and sex, from 1990 to the present, allowing comparisons over time, across age groups, and among populations 11)Global Burden of Disease official website: http://www.healthdata.org/gbd/about.

The analysis of the GBD research in the last years showed that the major risk factors contributing to the burden of disease are various dietary risk factors, metabolic risk factors and smoking 12)GBD 2013 Risk Factors Collaborators, Forouzanfar MH, Alexander L, et al. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2015;386(10010):2287-323. 13)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(10053):1659-1724. 14)GBD 2016 Risk Factors Collaborators. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet. 2017;390(10100):1345-1422. .

In 2013, poor dietary habits accounted for 11.3 million deaths. Elevated BMI alone caused 4 million deaths and 10.4 million people’s lives were taken by high systolic blood pressure  –  a condition influenced by the aforementioned. In comparison 6.1 million deaths were attributable to tobacco smoke 15)GBD 2013 Risk Factors Collaborators, Forouzanfar MH, Alexander L, et al. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2015;386(10010):2287-323..

Tobacco smoke has been at the center of efforts to improve health worldwide and is now declining at a global level. When it comes to other modifiable risk factors of NCDs, the picture looks quite different. From 1990 until 2015, deaths from elevated BMI have increased by 28.3% and even with the use of aggressive pharmaceutical therapies, the rise in obesity will likely lead to future declines in life expectancy and to the rise of various NCDs 16)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(10053):1659-1724.. The same detrimental development is true regarding stroke with increases in almost all risk factors (with up to 63%) over the last three decades 17)Feigin VL1, Roth GA2, Naghavi M2, Parmar P3, Krishnamurthi R3, Chugh S2, Mensah GA4, Norrving B5, Shiue I6, Ng M2, Estep K2, Cercy K2, Murray CJL2, Forouzanfar MH2; Global Burden of Diseases, Injuries and Risk Factors Study 2013 and Stroke Experts Writing Group. Global burden of stroke and risk factors in 188 countries, during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet Neurol. 2016 Aug;15(9):913-924. doi: 10.1016/S1474-4422(16)30073-4. Epub 2016 Jun 9..

The GBD 2016 filters the problems that are large, increasing, and variable across countries at the same level of development, as they likely warrant particular policy attention. Their analysis showed that components of diet, obesity, fasting plasma glucose (FPG), and systolic blood pressure (SBP) are the most prominent global risks fulfilling these criteria. They conclude that because of the strong interrelationships between these risks, the true driver of this cluster is likely diet, the risk in BMI, or both, with knock-on consequences for FPG and SBP 18)GBD 2016 Risk Factors Collaborators. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet. 2017;390(10100):1345-1422..

Solution

The Solution at Hand

NCDs are accountable for the largest portion of global deaths, healthy life years lost, and healthcare expenditures. Then again the largest number of NCDs is caused by only a few lifestyle risk factors. Among these risk factors the one with the biggest impact is diet.

This may sound too good to be true, as diet seems like something quite tangible, manageable, and resolvable. Following the data we’ve discovered, implementing healthy dietary habits would actually lead to a huge reduction of deaths and a huge increase in the life quality of billions of people. Furthermore, it would free a lot of the enormous financial and personnel capacities in the health sector, which are currently absorbed by NCDs.  All other fields in healthcare and medical research, among them the development of urgently needed antibiotic substances, the fundamental research on aging or rare diseases, and the progress of healing approaches like genetic therapy or biologics, are slowed down immensely by the focus on diseases that are completely artificial, as they are not biologically, but culturally conditioned.

Another positive side effect of healthy dietary changes in the broad public and especially among patients suffering from NCDs could be the newly added quality, time, and fulfilment health professionals would experience in their daily working life.

The only thing we need to know now is which dietary habits exactly are the ones solving the problem described. We will begin to explore the research in this field in our next article.

This article is part of the series “The Power of Nutrition”.

References   [ + ]

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