I was honored to have been invited to present this lecture at the Anthropology Department of Sonoma State University, on December 4 2015.
In this lecture I will look at:
- Trends in global population aging
- Differences across world regions and by gender
- Healthy aging: chronic disease and disability
- Determinants of health in older age
- Diet and lifestyle in health
- What can we learn from our living ancestors with respect to health and diet
The world’s population has been growing older particularly rapidly during the past half century. Today for the first time in human history, most people can expect to live into their 60’s and beyond. According to the World Health Organization, between 2015 and 2050, the proportion of the world’s population over 60 years will nearly double from 12% to 22%.
It used to be that younger generations surpassed the number of older people. However now, and even more so into the coming decades, there will be more older people than children The WHO estimates that by 2020, the number of people aged 60 years and older will outnumber children younger than 5 years.
An evidence of this is that many adults and young adults will have living (rather than dead) parents who live into their 80’s and 90’s, which didn’t happen too often before, when they died at younger ages. Also, more young children will get to know their grandparents and great grandparents, especially their grandmothers, given that women live longer than men.
There are two major reasons behind these ongoing changes. First, over the past century people have been dying a lot less. Medical developments that helped prevent death from infectious diseases such as influenza, pneumonia, and even diarrhea used to take people’s lives at very young ages. Second, women today are giving birth to a lot less children compared to what they did in previous decades. Over time, the consequence of these two factors, lower mortality and lower fertility rates is that gradually older people are outnumbering younger people, so that the proportion of older people is larger than the proportion of younger cohorts in a given population.
For instance: today in Japan, people aged 60 and older are 30% of the population compared to people under 15 years of age who are only 13% of the population.
The second consequence is that our lifespans have increased. We are living longer lives since we don’t die as often given our greater access to health services.
For instance a child born in Brazil today can expect to live 20 years longer than the same child born 50 years ago.
What are the implications of living longer lives?
Gains in the human lifespan have been an achievement of our time and our societies. They reflect the advancement in medicine, but also the greater access of medical services and education to a wider number of people.
Life expectancy was used for quite some time by scholars and policy makers, as an indicator of human progress, something that helped us measure how well we are doing as a society. However, at some point people started asking if living longer should be considered a goal in it of itself. If not, what conditions need to be met in order to make the most out of those extra years of life at old age?
The answer is obvious: health. We would need to ensure that we remain in good health in order to take advantage of the opportunity to live extra years of life and start new life projects.
It does not make sense to champion longevity without taking into account the quality of the lives we will live during our extended lifespans.
What common conditions prevent older people from living a quality life at old age?
- Chronic diseases such as heart disease, stroke, cancer, dementia, diabetes and obesity
- Disabilities that are age related, such as losses in hearing, seeing as well as functional disabilities—those which hinder the ability to move about and live their lives independently, which is something that older adults value a lot.
Living longer is not necessarily good if at the same time disabilities and diseases become more common, as they have in the past decades. For that reason, scholars and policy makers have drawn more attention to the measure of healthy life expectancy, a measure that takes into account disabilities in older age.
There are major differences in life expectancy across world regions, across countries, as well as between men and women. For instance, the pace at which populations are aging is much faster in developing countries compared to developed countries. For instance, in France the share of people 65 or older doubled in a period of 100 years (from 7% to 14%). However, it will take Brazil and China less than 25 years to reach the same growth in the older adult population.
Speed of population ageing. Source WHO.
Similarly, the countries that have gained the most in life expectancy, have also seen more years of life lost to disabilities. In the chart below, the blue-colored bars show chronic diseases, more prevalent in more developed countries. Although red colored bars (indicating infectious disease prevalence) are more frequent among less developed countries, they coexist with growing chronic non communicable diseases in fast-aging developing world. This chart shows that the longer people live the more likely they are to develop disabilities and disease – age is a major determinant of health in older life.
With respect to gender differences in the aging process, women worldwide have longer life expectancies– they live about 7 additional years compared to men. However, they are also more affected by chronic conditions such as diabetes, obesity, arthritis, and ostheoporosis. Women are also are more likely to develop functional disabilities compared to men which makes them dependent on the assistance and care of others to be able to perform everyday activities. As I mentioned earlier, this means that although women live longer lives, they will live more of these additional years of life with chronic conditions and disabilities.
The chart below illustrates the gender disparity in disabiltiy and life expectancy among older adults in Sao Paulo, Brazil between the years 2000 and 2006. At age 60, older women in Brazil can expect to live about 22 additional years of life. Of these additional years, they can expect to live 6 years with disabilities. By contrast, men at the same age of 60 can expect to live about 16 more years, and only about 2.5 of those years with disabilities–less than half of the additional disabled life expectancy compared to women.
The above results beg the question: How can we make sure we age well and with health?
Health at older life depends on genetic factors, personal characteristics such as socio-economic status, gender, ethnicity. It also depends on events and conditions experienced throughout the person’s life course for example lifestyle and behaviors such as diet, exposures to health risks, such as smoking, and the interaction with environments (accessible buildings or environments that encourage physical activity, access to health services, community and family support).
We have little or no control over our genetic endowment or our personal characteristics such as gender, race or ethnicity, or even the socio-economic conditions that we were born into or have to live in given moments of our life. Lifestyle, on the other hand, is something that we can modify more easily. An important part of our lifestyle is our diet.
Over the past century, there have been long term changes or transitions in what we eat which are very much related to the long-term changes in population aging and health that I explained at the beginning. These long term changes in diet are known as the nutrition transition. The nutrition transition goes hand in hand with the growth of cities and the related urban lifestyles that they bring about. For instance in the U.S. the urban and rural populations were about the same in the early 1900’s. Today the majority of the U.S. (about 75%) population lives in cities. In developing countries like Ecuador this change was much more dramatic: while in the 1970’s about 70% of the population was rural, today about the same proportion—70% of Ecuadorians live in cities.
Life in cities is dramatically different from life in the country: it is fast-paced, people are affected by stress and contamination. Also, given time limitations and long distances mean that people do not do exercise regularly, or nearly as much as what people living in rural areas have to.
In this context, and particularly since the early 20th century, many new foods entered our diet. A good example of a relatively new food in our history is Crisco.
Crisco is shortening, a kind of solid fat which is used for baking. Crisco was first marketed as a cheap alternative to pork lard and butter, which were the most common fats people used to cook with in the early 1900s. Crisco is produced in a factory by heating up cottonseed oil or other liquid seed oil like corn or soybean oil at high temperatures in a process called hydrogenation. This process creates a kind of fat molecule that we now know as trans-fat.
Crisco is a good example of the kinds of foods that were gradually introduced in our diets as the industry started to take greater control of our food supply. Since the mid 1900’s our consumption of industrialized foods and ingredients increased dramatically, particularly refined vegetable oils, such as corn oil or soybean oil–these refined oils had never been part of our diet.
Also we started eating high-calory and highly processed refined foods such as refined sugars and carbohydrates in amounts too high compared to what people living in cities, with lower physical activities, really needed.
The sharp rise in obesity, diabetes and heart disease and other chronic, non-communicable diseases over the past 50-60 years, are very much related to these historical lifestyle and dietary changes.
Diet is very malleable, it is something that we can modify more or less easily. For this reason countless studies have examined the associations between what we eat and the risk of developing specific chronic conditions such as heart disease, cancer, Alzheimer’s disease, and many others.
In spite of this, diet and nutrition are also some of the most contested fields of study. The evidence on the relationship between diet and specific health conditions is conflicting and is constantly changing with the advancement of research and the publication of new findings.
For example, the association of different types of fat and heart disease has been a major controversy in the literature and among policy makers over the past few years. Is fat good or bad for you? Scientists have not agreed. This lack of scientific consensus creates a challenge for policy makers and practitioners over how to advise diet and nutrition recommendations to an entire population.
At the same time, the confusion over what to eat has created an opportunity for the industry to sell products such as supplements, foods and diets that accompany claims of having a specific therapeutic effects or cure particular health conditions.
Coming from Latin America, I became interested in diet culture in the U.S., and soon noticed there is a subset of therapeutic diets which have gained popularity here over the past 15 years.
This subset of health diets have a common underlying philosophy: they look for solutions to modern health problems in the ways and the diets our human ancestors ate. I will comment on three of them.
The Paleolithic diet posits that we as human beings have not changed much, genetically for about 10,000 years since the Paleolithic era. Therefore, they say, we are meant to eat like our hunter-gatherer Paleolithic ancestors, a diet largely based on meat, vegetables, animal fats and nuts, but very little or no carbohydrates or dairy, which were introduced later with the dawn of agriculture. The Paleo diet has gained many adepts, particularly in the United States and Europe, although it has been highly questioned due to its unscientific claims about what the Paleolithic diet really looked like (for instance, its been shown that Paleolithic peoples did eat grains). With respect to its therapeutic value, Paleo diet has been questioned for not being very effective, but rather quite damaging for women’s health.
Weston Price Foundation
Another popular diet that looks to our ancestors for cues about how to gain health is promoted by an organization called the Weston A. Price Foundation. This organization is named after an American dentist who lived in the 1930’s who traveled the world studying the diets of healthy populations. The WAPF believe that optimal health can be gained by eating the traditional foods and diets of people around the world, particularly indigenous peoples in the Pacific, Africa, the Americas, and Australia. The WAPF are strong advocates of dairy products, notably raw milk and cheese, and animal fats such as lard and butter which they believe are protective against modern diseases like obesity, bone and dental problems, as well as against heart disease. As opposed to Paleo diet advocates who look further back in history, the WAPF have chosen more recent ancestors to imitate: their point of reference of healthy diets is as late as the 1950’s before the massive industrialization of food introduced processed foods into the diet and damaged our health.
One last example I want to comment on are the decolonial or decolonization diets, which have gained ground lately in the U.S. and Canada. Advocates of diet decolonization identify themselves with the broader political movements of indigenous and native peoples in the Americas. For this reason, they have chosen the period before the European conquest as the point of reference of what constitutes an optimal diet for health. For them, to “decolonize” the diet means to eliminate foods introduced during colonization (largely farm raised meats, dairy, eggs and other non-native foods like rice). As a consequence, decolonization diets have made a vegan or vegetarian (meat-less) interpretation of indigenous diets, in spite of the fact that in reality, native peoples of the Americas did eat a wide range of meats and fish. On a deeper level, to “decolonize the diet” means in their words “ to reclaim our cultural inheritance and wean our bodies from sugary drinks, fast food, and donuts. Cooking a pot of beans from scratch is a micro-revolutionary act that honors our ancestors and the generations to come.” (Luz Calvo and Catriona Esquibel Decolonize your Diet). In other words, their particular approach to diet has both therapeutic as well as political claims and motivations.
These three examples show the importance of culture in influencing what diverse groups of people today consider and construct as a diet for optimal health.To some it makes sense to look for cues for diet and optimal health in 10,000 years old prehistoric ancestors living before the dawn of agriculture. Yet to others, it makes sense to resemble more recent ancestors in the 20th century and up to the 1950’s before the dawn of large scale food industrialization. Yet others believe that native American ancestors living before the dawn of European conquest in the 1500’s can offer some cues as to how and what we should eat to gain health.
If we see beyond the politics that influence these perspectives on ancestral diets and health, the reality is that, as I said earlier, for the first time in history, we have ancestors that are not dead, but are still alive today. These are people in their 60s 70s 80s and even 90s who lived through the transitions and transformations in nutrition, population aging, health and disease that I discussed above. For this reason, these people’s testimonies and life histories are a unique opportunity to learn about how major transformations that happened over the course of the 20th century have impacted their lives and their health today.
In a future post, I will explain my motivations to create an ethnographic film and food education project Comidas que Curan to learn and listen to the stories my own living ancestors in Ecuador and Latin America.
World population is aging at fast rate. People are living longer, however the health of older population is not improving. Chronic diseases and disabilities are taking away the opportunity to live these additional years to the fullest potential.
Women fare worse than men in terms of health and life expectancy–-we live longer but with more of these additional years disabilities and chronic diseases compared to men.
Diet and lifestyle are one of many health determinants that can be modified to prevent chronic diseases and related disabilities.
There is controversy over what we should eat for good health. No consensus exists over what constitutes a healthy diet.
Many trendy diets today look to our ancestors’ diets for cues about health. Ancestors and older people become important sources of knowledge about health, diet and healing.
The transitions and transformations in population aging, nutrition and health of the past century provide a unique window of opportunity to learn about diet and health, as do the testimonials of our living ancestors today.