Nav: Home

World's 'better' countries have higher rates of cancer

October 11, 2017

The world's "better" countries, with greater access to healthcare, experience much higher rates of cancer incidence than the world's "worse off" countries, according to new research from the University of Adelaide.

Researchers say this is the result of relaxed "natural selection", because modern medicine is enabling people to survive cancers, and their genetic backgrounds are passing from one generation to the next.

The researchers say the rate of some cancers has doubled and even quadrupled in the world over the past 100-150 years, and that human evolution has changed away from "survival of the fittest".

Comparative anatomy and human evolution expert Professor Maciej Henneberg and PhD student Wenpeng You, both from the University's Adelaide Medical School, have been studying global cancer data from the World Health Organization, as well as other health and socioeconomic data from the United Nations and the World Bank of 173 countries.

The results of their studies, now published in the journal Evolutionary Applications, show an accumulation of cancer incidence over four to five generations.

"Modern medicine has enabled the human species to live much longer than would otherwise be expected in the natural world," says Professor Henneberg, head of the University's Biological Anthropology and Comparative Anatomy Research Unit.

"Besides the obvious benefits that modern medicine gives, it also brings with it an unexpected side-effect: allowing genetic material to be passed from one generation to the next that predisposes people to have poor health, such as type 1 diabetes or cancer.

"Because of the quality of our healthcare in western society, we have almost removed natural selection as the 'janitor of the gene pool'. Unfortunately, the accumulation of genetic mutations over time and across multiple generations is like a delayed death sentence," he says.

In their comparison of global data, Mr You and Professor Henneberg considered the top 10 countries with the highest opportunities for natural selection (the worse off countries), and 10 with the lowest opportunities for natural selection (countries considered to be better than others).

"We looked at countries that offered the greatest opportunity to survive cancer, compared with those that didn't," Mr You says.

"This does not only take into account factors such as socioeconomic status, urbanization, and quality of medical services, but also low mortality and fertility rates, which are the two distinguishing features in the 'better' world.

"Countries with low mortality rates may allow more people with cancer genetic background to reproduce and pass cancer genes/mutations to the next generation. Meanwhile, low fertility rates in these countries may not be able to have diverse biological variations to provide the opportunity for selecting a naturally fit population, for example, people without or with less cancer genetic background. Low mortality rate and low fertility rate in the 'better' world may have formed a self-reinforcing cycle which has accumulated cancer genetic background at a greater rate than previously thought," Mr You says.

Based on their analysis, Professor Henneberg and Mr You determined that the 10 countries with the lowest opportunities for natural selection (among the "better" countries of the world) are: Iceland, Singapore, Japan, Switzerland, Sweden, Luxembourg, Germany, Italy, Cyprus, and Andorra.

The 10 countries with highest opportunities for natural selection (among the "worse off" countries of the world): Burkina Faso, Chad, Central African Republic, Afghanistan, Somalia, Sierra Leone, Democratic Republic of the Congo, Guinea-Bissau, Burundi, and Cameroon.

The researchers found that the rate of most cancers in the 10 best countries was greater than in the 10 worst countries:
    Testicular cancer 14 times higher incidence in the top 10 best countries

    Lung cancer 12 times higher (smoking accounts for 50% of this cancer, the researchers say)

    Skin melanoma 10 times higher

    Brain cancer 6.5 times higher

    Pancreatic cancer 5.1 higher

    Prostate cancer 3.5 higher

    Leukemia 3.5 higher

    Breast cancer 2.7 times higher

    Ovarian cancer 2 times higher

Only cervical cancer went the other way, with rates of cervical cancer five times higher among the 10 worst countries. "This may be because of poor hygiene in the 10 worst countries, which is especially important in cases of cervical cancer," Professor Henneberg says.

He says that having removed natural selection as the "janitor of the gene pool", our modern society is faced with a controversial issue: "It may be that the only way humankind can be rid of cancer once and for all is through genetic engineering - to repair our genes and take cancer out of the equation."

This research builds on Professor Henneberg's and Mr You's previous work investigating the global incidence of type 1 diabetes and obesity.
-end-
Media Contact:

Mr Wenpeng You
PhD student, Biological Anthropology and Comparative Anatomy Research Unit
Adelaide Medical School
The University of Adelaide
wenpeng.you@adelaide.edu.au

Professor Maciej Henneberg
Wood Jones Professor of Anthropological and Comparative Anatomy; Head, Biological Anthropology and Comparative Anatomy Research Unit
Adelaide Medical School
The University of Adelaide
maciej.henneberg@adelaide.edu.au

University of Adelaide

Related Diabetes Articles:

Tele-diabetes to manage new-onset diabetes during COVID-19 pandemic
Two new case studies highlight the use of tele-diabetes to manage new-onset type 1 diabetes in an adult and an infant during the COVID-19 pandemic.
Genetic profile may predict type 2 diabetes risk among women with gestational diabetes
Women who go on to develop type 2 diabetes after having gestational, or pregnancy-related, diabetes are more likely to have particular genetic profiles, suggests an analysis by researchers at the National Institutes of Health and other institutions.
Maternal gestational diabetes linked to diabetes in children
Children and youth of mothers who had gestational diabetes during pregnancy are at increased risk of diabetes themselves, according to new research published in CMAJ (Canadian Medical Association Journal).
Two diabetes medications don't slow progression of type 2 diabetes in youth
In youth with impaired glucose tolerance or recent-onset type 2 diabetes, neither initial treatment with long-acting insulin followed by the drug metformin, nor metformin alone preserved the body's ability to make insulin, according to results published online June 25 in Diabetes Care.
People with diabetes visit the dentist less frequently despite link between diabetes, oral health
Adults with diabetes are less likely to visit the dentist than people with prediabetes or without diabetes, finds a new study led by researchers at NYU Rory Meyers College of Nursing and East Carolina University's Brody School of Medicine.
Diabetes, but not diabetes drug, linked to poor pregnancy outcomes
New research indicates that pregnant women with pre-gestational diabetes who take metformin are at a higher risk for adverse pregnancy outcomes -- such as major birth defects and pregnancy loss -- than the general population, but their increased risk is not due to metformin but diabetes.
New oral diabetes drug shows promise in phase 3 trial for patients with type 1 diabetes
A University of Colorado Anschutz Medical Campus study finds sotagliflozin helps control glucose and reduces the need for insulin in patients with type 1 diabetes.
Can continuous glucose monitoring improve diabetes control in patients with type 1 diabetes who inject insulin
Two studies in the Jan. 24/31 issue of JAMA find that use of a sensor implanted under the skin that continuously monitors glucose levels resulted in improved levels in patients with type 1 diabetes who inject insulin multiple times a day, compared to conventional treatment.
Complications of type 2 diabetes affect quality of life, care can lead to diabetes burnout
T2D Lifestyle, a national survey by Health Union of more than 400 individuals experiencing type 2 diabetes (T2D), reveals that patients not only struggle with commonly understood complications, but also numerous lesser known ones that people do not associate with diabetes.
A better way to predict diabetes
An international team of researchers has discovered a simple, accurate new way to predict which women with gestational diabetes will develop type 2 diabetes after delivery.
More Diabetes News and Diabetes Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.