Today’s blog is something of a
cheat. It simply lays out the content of the individual chapters of my new
book:’Something to chew on – Challenging controversies in food and health’. I
wrote this book to help the average person to gain some understanding of the
mainstream science of food & health and in so doing to de-bunk many common
myths and misperceptions. The book is available at www.ucdpress.ie, at www.amazon.co.uk and http://www.bookdepository.com. If you
are so inclined, you can “like” the Facebook page of the book here.
Something to chew
on
Challenging controversies in food and
health
Mike Gibney
Chapter summaries
Chapter 1: With regard
to food
This chapter sets the scene for the book. It
describes the evolution of the modern food supply beginning with the era of
widespread malnutrition in the most developed economies from the turn of the 20th
century. The extent of this
malnutrition was exacerbated by two world wars either side of a great economic
depression. Following the end of
World War II, a remarkable period of investment in science and technology
emerged as the global economy expanded. Agricultural output and efficiency
soared and as more women entered the work force, the demand for more
convenience food and the necessary kitchen technology to use these new products
was developed. Food companies grew by mergers and acquisition and the great
retail giants emerged. The era of cheap and abundant food had arrived. During
this post war period the science of human nutrition also evolved from a century
of researching what was essential to sustain life to an era of researching what
was necessary for optimal health. Nutrition had arrived on the political
agenda. And then the Vietnam War started an era of challenge of the military
industrial complex and the concept of people power emerged from the hippy and
civil rights movements in the US to the student riots of Europe. Now an era of
mistrust in science and technology evolved and the green movement began to
shape the political agenda. And food now came under the microscope. The public
got scared of high tech food with an increasing mistrust of the food industry
which was blamed for food scares and an epidemic of obesity. That led to the
development of a rapid expansion of interest in organic and ethical food. The
advent of the BSE crisis obliterated the reassurances of the government in the
safety of the food chain and the arrival of genetically modified foods
heightened this mistrust. This book looks at all these challenges to the human
food chain and attempts to give a scientific dimension to what are often
emotional issues surrounding concerns about food.
Chapter 2: Sugar and spice and all things nasty
Plants abound in natural chemicals which exist
for normal plant function including germination, growth, reproduction,
repelling pests and attracting the birds and bees. It is these that give plant
food their beautiful colours and their delicious tastes and flavours. They also
give rise to a wide array of natural plant compounds from pure poisons
(hemlock), to the downright dangerous (cocaine, nicotine) and onwards to
natural plant compounds which have healthy properties (which lower blood
cholesterol or which lower blood pressure). Irrespective of their effects on
man, these natural compounds are not regulated. They are after all natural.
Man-made chemicals are very strictly regulated and this chapter deals with food
additives, pesticides and contaminants as examples of man-made chemicals all of
which must prove they are safe to enter the food chain. The toxicity of the
natural and man made compounds are compared showing an equal if not a greater
burden of risks from natural compounds. It also deals with the practice of
adding nutrients to foods through food fortification. Finally, this chapter
challenges the myth that organic food is more nutritious, more tasty, more
flavoursome and more environmentally friendly than conventionally grown
crops.
Chapter 3: Modified
foods: genetic or atomic?
The human food chain has been genetically
manipulated from the dawn of agriculture and this chapter examines the present
scare about genetically modified foods. It first describes conventional plant
breeding which is preferred by the environmental groups in their vigorous
opposition to GM crops. The common belief is that conventional crop breeding is
a loving task of nature carried out by a devoted plant breeder out in the
field. This is not so.
Conventional plant breeding involves hitting thousands of plants with levels of
atomic radiation 100 times stronger than that used in the application of radiation
to cancer therapy. The plants genome is rattled to bits and the vast majority
of the mutants die. But some survive and go on to exhibit new properties which
can then be crossed back with the normal variety in the hope of transmitting
the new desirable trait. The UN International Atomic Energy Agency champions
the use of atomics radiation to induce mutations and boasts over 2000 crop
varieties in existence today developed using this totally unregulated
technology. In contrast, for GM technology, the genes to be inserted are known
in advance to be linked to some desirable characteristic and only these genes
are inserted. The chapter challenges the claims of environmental groups that GM
foods are a danger to human health and to the environment.
Chapter 4: The metrics
of food and health
We are constantly learning from reports in the
media about new findings linking some food or other with this or that disease.
How is this done? This chapter looks at the tools available to measure food and
nutrient intake and makes the point that they are all fundamentally flawed. All
dietary surveys will encounter very significant levels of the under-reporting
of the true intake of food. In simple language, it is the norm in large dietary
surveys for a very significant proportion of the study population to fail to report
(a) ever eating some food, (b) reporting the consumption of the food but
under-reporting the frequency of consumption and/or(c) under-reporting the
quantity consumed at a given eating occasion. This phenonomen might be
explained on the basis that most people have one approach to food intakes on
Mondays which reflects a desire to have a truly healthy week ahead and which
quite often falls by the wayside later in the week. When asked to record their
usual dietary patterns, survey participants frequently report the restrictive
Monday type for the whole week. Thus a major problem is that in the measurement
of patterns of food consumption, we simply cannot be accurate. Notwithstanding
these limitations, we now seek to link dietary patterns with those of various
diseases, which is the science of epidemiology. when a positive or negative
association is found, it means just that, an association. It cannot prove cause
and effect. To do that we need to construct an experiment in which two groups
are compared where everything is identical except the test food or nutrient. We
examine two contrasting cases of dietary intervention.
Chapter 5:
Personalized nutrition – fitting into your genes
When you general practitioner tells you that
your cholesterol is high, by high, he or she means above a reference point
established in large population studies. Such studies show that on average,
individuals with cholesterol values above that point have a higher than average
likelihood of going on to develop heart disease. In that last sentence, the
word average was used twice. Suppose now the GP could establish in this regard
that you were in reality above or below average in the likelihood of developing
a heart attack with your level of cholesterol. Then your advice might be a little
more personalised than simply average. The mapping of the human genome in 2003
was a major step in making that possible. This chapter explores the concept of
personalised nutrition by which is meant a set of nutritional advice which is
targeted specifically to you on the basis of our knowledge of your genetic make
up and of our developing understanding of how the human responses to changes in
nutrient intakes are very mush influenced by known genetic variability. Many
companies will sell you a genetic analysis and personalised dietary advice over
the internet for about US $500. This chapter casts serious doubt on the
reliability of this advice and explains also the great difficulty that the
human food chain would have in matching true genetic requirements for nutrients
with our present day retail system. However, it does try to foster the hope
that in the course of time, we will reach a point where simple dietary advice
on diet and conditions such as blood pressure, weight gain, cholesterol or
allergy will all have some robust element of genetic analysis to sharpen the
tools of preventative nutrition.
Chapter 6: Plastic
babies – the phenonomen of epigenetics and nutrition
When a foal is born, it knows immediately to
stand up on all fours, to recognise its mother, to run with the herd and to
interpret the sight sound and smell of danger. Its brain is hardwired and all
switches in the nervous system are fully operational. In contrast, a human baby
is born with quite an immature brain and for good reason. Babies born in
Belfast, Burundi, Beijing and Baghdad will all have to recognise speech but
speech in quite different languages. They will have to learn to behave within a
society into which they are born and the social norms vary greatly across
cultures around the globe. We inherit DNA from our parents and the sequence we
end up with is a random mix of both - Dad’s hair, mum’s eyes. But the sequence
once made is never changed. What distinguishes the foal from the human baby is
the extent to which the genetic sequence is managed. Imagine the genetic
sequence to be like a complex electronic code to manage a sophisticate lighting
system. All the codes and their sequences for the lighting system remain
unchanged. But the settings of the switches can be changed - more of this and
less of that. From the pre-natal period in the womb through to the first few
years of post-natal life, we
slowly and methodically make adjustments to the genetic code, not to its
sequence but to the extent to which each gene in the sequence is switched up or
down. Once finally adjusted, that is it for life. This chapter looks at this
phenonomen and the very important role that diet plays in this tweaking of the
human genome and in turn how that tweaking made in the early days of life can
greatly influence our health four to five decades later. It looks at the
uniqueness of human pregnancy which is necessitated by our larger brains and at
the need for our genetic development and our brain development to be highly
flexible at the onset of life. That is what gives us our evolutionary advantage
and we will look at that in the context of man’s probable aquatic origin.
Chapter 7: Your
insides out: food - the gut and
health
In recent years we have begun to appreciate
that the gut is an organ which plays a central role in food and health, not
just in digestion and absorption of the food we eat but in our immune system,
in obesity and in our reflex actions in times of stress. The present chapter
explores some of the very exciting science that is emerging from this research
with far reaching consequences for food and health. The stress element of our
gut is governed by a major nervous
system which has evolved quite independently from the brain. It is required to
prepare us for “fight-or-flight” circumstances and is responsible for a host of
common phrases such as “butterflies in
your stomach” or “not having the guts”
for some challenge. The bacteria in our gut weigh 1.5 kg and have 100 times
more DNA than the human body which hosts them. The two have established a
“treaty” in which one gives to the other in a symbiotic way. We gain energy
from the fibrous foods they alone can digest and they gain access to fuels we
can’t use. They actually can cause our genes to be up or down regulated to suit
them and they work with us to make sure that rogue bacteria don’t break the
treaty leading to sickness. In recent times, these bacteria have been shown to
play a pivotal role in obesity. Rats raised in totally sterile conditions don’t
get obese on diets that would normally cause obesity in a non-sterile
environment. The gut will be a major focus of food and health in the future
Chapter 8: A tsunami
of lard: the global epidemic of obesity
Obesity is seen as a simple problem: people get
overweight because they eat more calories than they expand. That’s a bit like
saying “cancer is simply a cell gone wrong”. This chapter begins by briefly
explaining the biology of the diabetes associated with obesity and then moves
to the biology of the control of food intake. It makes the point that rodent
studies of the regulation of food intake are of interest but we have a large
part of our brain, the neo-cortex, responsible for higher human functions,
which overrides simple biology signals such as hunger. We refuse to eat cat
food when hungry whereas a rat will readily do so. We then move to genetics and
specifically to twin studies and show how powerful the heritability element of
obesity is. A strong case is made in this chapter that much of the research in
this area focusing on foods responsible for obesity (fast food, soft drinks,
processed foods) is going nowhere largely because of the reasons outlined in
chapter 4 on our poor ability to accurately quantify food intakes. The case for
a greater focus on linking genetics to food related behaviour is made. Dieting
is dealt with as is physical activity and the stigmatization of the obese.
Finally this chapter looks at little known data on the rise in obesity pointing
out that obesity has been rising in the US in waves dating back to the early 20th
century. The conventional wisdom that it is simply junk food is challenged and
data on inter-generational augmentation of obesity through epigenetics,
discussed in chapter 6 is discussed.
Chapter 9: Greying
matters – food and the elderly
This chapter outlines the dramatic demographic
changes that will occur in the developed countries in the next 30 years. In
some countries such as Japan and Sweden, over 1% of the population will be over
100 years by 2050. The chapter outlines the areas of aging which can be
influenced by diet. The decline in the regulation of food intake and an
obesigenic environment mean that we now have the phenonomen of the frail obese
elderly; not enough muscle and too much fat. We look at bone health and its
decline from the early part of mid life and deal with the conflicting advice on
sunshine from two different camps, those concerned with skin cancer and those
concerned with exposure to sunlight to get adequate vitamin D. The chapter
deals with sarcopenia, the loss of muscle in the elderly and also the role of
diet in declining eye sight. Finally, the chapter deals at length with memory
and its decline with aging and reviews the relevant data linking diet and
Alzheimer’s disease. The link between obesity in mid life and the risk of
Alzheimer’s disease in the elderly is explored.
Chapter 10: Food and
Health – The science, policy and politics
The role of four players in the drama of food
politics is explored. First the practice of linking major multinational food
companies with the problems of over-nutrition is explored and challenged. Potatoes account for 12% of caloric
intake in Ireland and have a zero advertising budget. All chocolate combined
accounts for 2% of caloric intake and has a massive advertising budget. Most
likely, potatoes are more important in over-nutrition in Ireland than
chocolate. We look at 4 classes of scientists which range from the one wired to
the laboratory and never gets involved in the regulatory side if things to the
“issue advocate scientists” who get involved everywhere and push an a priori agenda. Next we look at the UN
agencies and an independent analysis of their style of risk assessment and risk
communication and show large shortfalls in proper procedures in the analysis of
particular problems. We also look at how they can pre-empt scientific
publications they don’t like with their own gloss on events. Finally we turn to
NGOs who play a powerful role in our participatory democracy and the chapter
accuses some NGOs of being dogmatic and anti-science.
Chapter 11: The
hazards of food
This chapter explains how society assesses risk
in respect of our food supply and explains the detailed process of testing for
safety. It introduces the reader to the concept of risk management and looks at
the EU’s precautionary principle which is being used to block innovation such
as GM technology. We then look at risk communication and we show how consumers
presented with the same data expressed in different ways (% who will die during
treatment or % who will survive) adopt different stances. We explore the
concept of “world views”, how these are acquired and how these shape the
emotional response to perceived danger. The chapter argues that throwing
“knowledge” at consumers will not allay their fears since these fears are
frequently emotional and thus not readily open to rational argument. It
contrasts how regulators (mostly scientists) see risk and how consumers see the
same risk. For the consumer the fear increases as they lose control over the
avoidance of the risk and as the risk gives rise to effects which are both
dreaded unfamiliar (BSE). In contrast, real public health risks such as obesity
are seen as controllable (“I can lose weight whenever I want”) and are both
familiar and not dreaded
Chapter 12: How the
other half dies
This chapter looks at the problems of global
malnutrition. “Wasting” is the condition of malnutrition seen on TV, gaunt
corpse-like children with zero fat beneath their skins. “Stunting “ is the
condition of malnutrition where a child is too short for their age. The final
form of malnutrition is that of “hidden hunger”, the blindness of vitamin A
deficiency, the anaemia of iron deficiency and the goitre of iodine deficiency.
The chapter argues that the global aid agencies, the IMF and the World Bank in
the Thatcher-Regan era, adopted a policy in development aid of getting the
fiscal system working and leaving it all to the markets. This is only slowly
now being abandoned and investment in agriculture and nutrition is now back on
the agenda. The chapter looks at recent books which argue that Africa is being
starved of science by anti-GM and organic farming NGOs and which look at the
basic geo-political reasons for the existence of the world’s “bottom billion”.
The chapter looks at how malaria and HIV/AIDS is wrecking Sub Sahara Africa.
The chapter ends with the Alliance for a Green Revolution for Africa led by
Kofi Annan which is seeking to sink billions into improving African
agriculture. This requires an investment in scientific agriculture including GM
crops.
Chapter 13: Mankind
and Mother Earth
Previous predictions of doom and gloom (Club of
Rome, Y2K and the Ozone layer) are examined in relation to the lingering
scepticism on global warming and climate change. We then look at leading
climate scientists who believe they have to “sex up” the data to get attention.
Thereafter the focus is on scientific facts on two vistas of the environment
and the human food chain – how agriculture influences the environment and how
environmental changes influences agriculture. We begin by looking at the global
population and with a focus on the developing world where the main growth of
population will occur. The 50% increase by 2050 in global population (6 to 9
billion) will be mostly in developing countries. Agriculture affects the
environment in two ways. It produces large amounts of greenhouse gases
primarily through energy demanding livestock production and through
deforestation and desertification. Secondly agriculture absorbs over 70% of
global water, presently at a rate where extraction from aquifers is 2-5 times
the rate of re-charge with rainfall. All of the various solutions mooted are
mentioned from no-till farming to drip irrigation. We also look at and refute
the importance of “food miles” as quantitatively important in climate change
and make the case that this is just part of the repertoire of the anti
globalisation, anti-capitalism movement. Finally, we look at how changing
temperatures and rainfalls will affect global agriculture. The developing world
will fare worst. They will get hotter to the point where crop yields will fall;
they will get longer periods of drought and heavier but more intense rainfall.
In the developed world with the exception of Australia, there will be higher
crop yields from higher levels of atmospheric carbon dioxide and from higher
temperatures.
Chapter 14: Reflections
and projections
A final chapter with a focus on the two great
food tragedies of modern times: obesity and malnutrition
