The
Minnesota Coronary Experiment (1968-1973) showed that patients changed their
diet; had significant drops in cholesterol and increased risk of dying. Another
study (The Sydney Diet Study in the 1960s) found that males who decreased their
intake of saturated fats and lowered their cholesterol level had an increased chance of dying from a heart attack. Other studies have shown the same or similar things. In fact another study a decrease in
cholesterol led to an increase in weight of 40%.
What is happening here? Why have studies shown decreasing saturated fats leading to a lower cholesterol level and an increased level of heart
attack?
There are two theories.
Theory one: People change the type of fat in their diet.
Firstly
we can say your cholesterol level is a rough guide to the total amount of good
and bad fat in your blood stream. Just the level of cholesterol, by itself,
doesn’t say anything about whether the fat is good or bad. Your cholesterol level could go down but the
fat in your blood stream may go from good to bad.
What is bad fat?
Saturated fats, trans fats and Omega-6 polyunsaturated fats have all been described as bad.
A trans fat begins as an unsaturated fat but processing
changes the fat to cause it to behave badly (like the worst type of saturated
fat). Processed foods can contain
large amounts of trans fats due to manufacturing processes which may include
super heating of oils and fats during food production. Trans fats are common in
deep fried foods, commercial cakes and biscuits, pies and pastries.
Omega-6
polyunsaturated fats are also often seen as bad because they are pro
inflammation.
What is good fat?
Fat
is an essential element. Fat is needed for hormone production. Both fat and
cholesterol are needed to produce serotonin and help healthy cell functioning.
Also important in immunity and liver function.
Fat
is needed for the making of cell membranes. Also important in the functioning
of cell membranes (keeping cells hydrated).
Fats
provides nutrients such as Vitamin E.
In general unsaturated fats (both
polyunsaturated fats and monounsaturated fats) are described as good. Except omega-6 polyunsaturated fats which are thought of as bad. Omega-6
polyunsaturated fats (found in most vegetable oils) are pro-inflammatory and
have been linked to heart disease and cancer. Omega-3 polyunsaturated fats are thought
of as good.
Polyunsaturated fats are found in
oily fish, nuts (brazil nuts, walnuts) and seeds.
Monounsaturated fats are found in
olive oil, avocado, nuts (almonds).
Some experts say all natural fats
are good: butter, coconut oil, extra virgin olive oil, full cream milk, fee-range eggs, cheese, plain yoghurt, cream,
and grass-fed meat. These experts say it is very difficult to overeat on these
fats because they are filling by nature. You feel full after eating them. These
experts describe fat as either natural or processed. Not describing fat as
saturated or unsaturated.
Theory two: People replace cholesterol with refined
carbohydrates.
Decreasing saturated fats results
in an increased consumption of refined carbohydrates which has been linked to
obesity, diabetes and high blood pressure.
The Journal American Medical Association has said that a low
fat diet leads to increased insulin resistance (precursor of diabetes) and
increased obesity. And we need to
consider that low fat products are more common than ever and we as a nation are
more overweight or obese than ever.
Fat
consumption is self-regulating. When we eat fat, a hormone (cholecystokinin)
tells us we are full. It is different with sugar. Eat excess sugar and your
body will tell you to eat more.
Are we obese because of fat or sugar?
My
conclusion
The
evidence points towards sugar as the guilty culprit. Lowering your cholesterol
level by changing the type of fat you eat is unlikely. Much more likely is you decrease
your cholesterol level by decreasing your total fat intake and simultaneously increase
your intake of refined carbohydrates.
Other studies (not mentioned here) have implicated sugar as the cause of
heart disease.
Charging
sugar with the crime of causing heart attacks doesn’t mean ignoring the fat in
your diet. The evidence is pretty good that an excess of certain fat is bad for
you. The wrong type of fat is an accomplice to the crime. The wrong type of fat
is possibly trans fats, saturated fats and omega-6 polyunsaturated fats.
Diet
means everything you eat. And that’s the way it should be. If you don’t want
diseases where diet is implicated then think about your total intake and type of
both fat and refined carbohydrates.