â€¢ I am not going to talk (much) about fat in the diet;
â€¢ I am not going to talk about my weight (which is coming down, by the way, partly by my eating dinner off a smaller plate);
â€¢ I am not going to advocate any particular foods or fads or diets; and
â€¢ I am not going to talk about any physiological measurement of health.
I am going to highlight some recent research, some of it done at the Garvan Institute in Sydney, which shows the importance of different types of perfectly natural fat storage inside everyone's body.
The body naturally has different types of white fat, for different purposes
Fat is an organ – or rather several organs collectively called "adipose tissue". Your body utilises various types of fats ("lipids") in order to maintain its structure and function; you would die if you had too little fat.
This does not mean you have to eat a lot of fat – in fact the vast majority of the fats that your body needs are made up from scratch, from the digestion of the foods that you eat, whether carbohydrates, protein or fat, or even alcohol. The molecular pieces that result from the breaking down of all these nutrients in your mouth, stomach and intestine are the building blocks of everything your body uses to function, including all the specialised fats.
There are several different places where actual visible white fat is found, and each type has a particular role to play, a different chemical structure appropriate to its purpose, and a different physiology (physical property in the body).
Enjoy the bbq
Learn to love your "essential fats".
Many types of fat are classed as "essential" and you will retain a certain minimum amount of these even if you eat less (unless you are very sick or severely starving). The most obvious is the dense white fat that protects your heart, kidneys and all other internal organs – as well as acting as shock-absorbers around your joints. It is also found around the reproductive organs of women, and is a major component of breast tissue. Your total amount of fat, including this essential tissue, is approximately 9% to 12% if you are a healthy woman; and 3% to 5% if you are a man.
The fat around your stomach and heart, in particular, will increase if you eat more than you need to fuel your bodily functions, and this excess build-up is known to be harmful for the working of these organs. Some is essential; too much is not so good.
Other types of essential lipids (fats) cannot be so easily seen. Specialised fats called phospholipids, along with a bit of cholesterol, make up the little envelopes called "cell membranes" that keep the inside in every single cell in your body "in" – and also keep the outside "out".
Other types of fats are important in the functioning of the brain; in helping the digestion of some vitamins; in forming the yellowish mass inside the bone marrow which supports the formation of blood cells and some immune cells; in making the myelin sheaths that insulate the nerves (if this breaks down or is defective, then a person may suffer from multiple sclerosis); as connective tissue holding muscles together; in being building blocks for some bodily structures; and in various other places. (livehealthy.chron.com; www.wisegeek.com)
Fat for storage – an individual matter
"Subcutaneous" (meaning "under the skin") fat is also white and a bit squishy, and it is found – as the name implies – spread around in a layer under your skin. A certain amount of this fat is also essential. It is the main fuel storage organ; it acts as cushioning for our total body; it maintains the stretchiness of our skin; and it releases certain necessary control hormones into our blood.
We are not like a car – we do not suddenly come to a halt when our stomach is empty. When our body signals that the immediate "fuel" of glucose is in short supply in our bloodstream, then a cascade of chemical reactions is initiated, and different enzymes and hormones come into play to do their job of breaking down a little of this subcutaneous fat into simpler molecules. Eventually, more glucose is generated from this store. (This storage fat was originally made up from glucose after digestion of your foodstuffs; it returns to glucose when needed for fuel).
Some of this beautifully orchestrated ballet dance of control chemicals actually happens from within this adipose (fat) tissue itself.
However, in our currently very well-fed population, most of us eat more than we need to supply our day-to-day energy needs. Guess where the excess is stored? Yes, in this under-the-skin fat that we notice if we try to put on our shorts or a special outfit from a few years ago. Different individuals store fat in different places, and it is thought that those who are unfortunately genetically predisposed to get a big round 'apple-shaped' belly are most at risk for a number of health problems. You can reduce this stored fat by eating less – less of anything, as long as the total is less. However, it is wise not to go overboard and lose too much at once. From my own experience, I advise you to go slowly and seek advice if you feel you need to diet.
Many adipose (fatty) tissues are important in the making and control of reproductive hormones, in both men and women. All the male and female sex hormones, as well as Vitamin D, start with a molecule of cholesterol which is produced in the liver. Interestingly, your liver makes all the cholesterol you need from the products of digestion, and it makes far more than you could ever eat from your food. In any case, the cholesterol from food is broken down by digestion, and doesn't just float around and become absorbed as a whole molecule. (www.ivy-rose.co.uk (easy to read); histologyolm.stevegallik.org (scientifically more detailed))
Like these beautiful trees in Mt Beauty
New research - brown fat can increase with exposure to cold
Brown fat in humans has traditionally been seen as an enigma. It has long been known that, in the babies of humans and other mammals as well as in animals that are hibernating, it produces heat, not energy that can be used for activity. It is brown because it contains mitochondria, which are small organelles (tiny organs) present inside most cells that enable the oxidation ("burning") of fuel. (These mitochondria are responsible for the colour of muscles, where they do produce useful energy).
Until quite recently, it was thought that adult humans had only a few small pockets of brown fat, usually around their shoulder region, and that it had no function. Last month, researchers from Sydney's Garvan Institute conducted a very neat experiment which showed that, even in healthy adults, the amount of brown fat can increase when they are exposed to moderate cold (down to 19 degrees C instead of 24 degrees for a month, while they were sleeping), and that there is more than originally thought (though still only about 50-70 grams – half the weight of an apple).
Another exciting finding from these researchers is that, during the time when these test subjects had more brown fat, their insulin sensitivity was higher – meaning they utilised the glucose fuel from their blood more efficiently and were more resistant to type II diabetes. There were also changes in the hormones that regulate hunger and a feeling of fullness. (www.sciencedaily.com)
It is too early to know what practical implications these findings will yield, but it is an important reminder that we do not yet know everything about the workings of the human body, nor the effects of various environmental factors on its inner mechanisms. It is but only one step forward in this type of research.
Finishing with a warning: you should check "scientific" facts you hear
While preparing this article, I heard a news item about this same research. However, the reporters over-simplistically gushed about "good fat" and "bad fat". As noted in this article, all fat has some "good" and natural roles to play in the body.
In biology and nature, there is no such thing as "good" and "bad" - only what we humans think. All processes that help us continue living are wondrous and amazingly beautiful. If you ever hear some scientific results that seem to be reported with too much of a "wow" factor, then try to find more than one source to double-check the information. If it seems too good to be true, then it probably is.
Proverbs 9:6 (NLT): "Leave your simple ways behind, and begin to live; learn to use good judgment"
Horses too enjoy the fat of the land
Dr Mark Tronson is a Baptist minister (retired) who served as the Australian cricket team chaplain for 17 years (2000 ret) and established Life After Cricket in 2001. He was recognised by the Olympic Ministry Medal in 2009 presented by Carl Lewis Olympian of the Century. He mentors young writers and has written 24 books, and enjoys writing. He is married to Delma, with four adult children and grand-children.
Mark Tronson's archive of articles can be viewed at www.pressserviceinternational.org/mark-tronson.html