In the second of his two-part article examining what may be the biggest controversy in modern medical history, Albert Cilia-Vincenti shows how recommendations for a balanced healthy diet are based on outdated science.
Doctors and nutritionists demonised dietary saturated fat for 60 years, linking it to high blood cholesterol and cardiovascular disease (mainly heart attacks and strokes). We taught at medical schools, and advised the public, that the culprits, saturated fats in meats, milk, cream and cheese, not forgetting the cholesterol in egg yolk and seafood, were to be avoided to prevent high blood cholesterol, clogging of arteries and obesity.
In these last few years, however, this preventive medicine dogma has been severely challenged, resulting in the most serious controversy and landmark reversal in medical scientific thinking of modern times. How could this 60-year-old dogma of nutritional medicine be suddenly declared probably unsound and needing some revision?
A recent review of the immediate post-war American research linking dietary saturated fat and heart attack rates in a number of different population groups found the research to have been flawed in design and statistics. It was over-interpreted, in an almost obsessional fervour to prove that the dietary cause of heart attacks had been found and the problem solved.
At the time (1950s), a London physiology professor claimed that the culprit was not fat but sugar. However, he was ridiculed and the American view of the connection between saturated fat, blood cholesterol and cardiovascular disease prevailed.
Apart from finding fault in the original American clinical trials (observational and not double-blind), recent researchers could not regularly replicate the claimed link between dietary saturated fat, blood cholesterol and heart attack. Adding to doubts and controversy, some trials also showed that about half of heart attack patients arriving at hospital had “normal” blood cholesterol levels.
The routine laboratory blood cholesterol profile consists of total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides. For decades, LDL has been regarded as the bad cholesterol and, if raised, was a marker of risk for heart attack. If it couldn’t be lowered by cutting down on dietary saturated fat, medicines (statins) had to be used to lower it.
But a recent fundamental laboratory discovery has ruffled many a feather in the cardiology community. It turns out that there are at least two main different types of LDL (and not just one bad one), a good type and a bad type. Routine laboratories measure both together, so with a moderately raised LDL, one does not really know whether it’s the bad or the good fraction of LDL which is raised. So how can one tell if the bad fraction LDL is raised when the two LDL fractions are not measured separately?
It so happens that the surrogate marker for a raised bad fraction LDL is a raised triglycerides level, often accompanied by a low HDL (good cholesterol), both of which are routinely measured and perhaps not given enough importance. Recent researchers claim that when the triglycerides and HDL are normal, moderately raised total and LDL cholesterols can be ignored. Some have even gone so far as to state that the importance of LDL as a marker of risk for heart attack is history.
Some cardiology clinics are already recommending that a raised LDL must be accompanied by a raised triglyceride level to be clinically significant and to require action. However, the huge statin pharmaceutical industry is still linked to routine laboratory LDL levels.
Another important finding which may surprise many is the more recently recognised fact that although saturated fat may mildly to moderately raise routine LDL levels, it also raises HDL, the good cholesterol. Furthermore, what raises triglycerides and lowers HDL (bad risk markers) is not saturated fat but too much sugars and refined carbohydrates that produce high blood sugar, such as all the foods made from white flour, white rice and potato.
“Our bodies need good dietary fat because all our cell membranes and hormones are made from fat”
The crux of the medical controversy is therefore the more recent evidence linking high blood sugar (from dietary sugars and refined carbohydrates), rather than dietary saturated fat (in meats and dairy produce) and cholesterol (in meats and egg yolks), to heart attack and stroke risk (and diabetes type 2).
This more recent evidence suggests saturated fat of meats and dairy produce (milk, butter and cheese) is healthy fat (in moderation). Our bodies need good dietary fat because all our cell membranes and hormones are made from fat. Other good fats the body needs are the so-called omega-3 ones which are found in fish and some plants, like flax seed.
Are there any bad fats? Yes, particularly bad are the so-called trans-fats found in all margarines and partially-hydrogenated vegetable oils (vegetable cream and vegetable lard). The French health department also regards palm oil as a bad fat. The French staple diet is rich in good saturated fat (butter, cheese and meats) and they have the lowest heart attack incidence and mortality in Europe.
The story of saturated fat, cholesterol and cardiovascular disease is now beginning to sound like the longest running “fake news” of modern medicine. However, foods made from animal products (meats and dairy products including eggs) are not entirely innocent for our health. A diet based on too much animal products is suspected of increasing the risk for several cancers. The French may have the lowest heart disease rate in Europe but they are close to top of the league for cancer rates.
Recent research on gut bacteria (which are now thought to affect, either favourably or negatively, many vital body functions) suggests that good bacteria need dietary plant and fruit fibre and other compounds to flourish and predominate in the gut. Sugars, refined carbohydrates and animal products may encourage bad bacteria.
At this stage we need to clarify that carbohydrates come in two types, “good” and “bad”. The good ones are vegetables, fruits, nuts and whole grains, the latter including whole grain bread, pasta and rice.
Very recent World Health Organisation research confirms previous claims that dietary fibre (in vegetables, fruits, nuts and whole grains) lowers risk for heart attack, stroke, diabetes type 2 and some cancers, including breast and bowel. Bad ones are sugars and refined grains, such as white flour, white rice, white pasta and potato.
These are regarded as bad because, although they do contain a little protein, the refining process removes practically all the vitamins and fibre which existed in the grain crust. Refined grains therefore have almost no nutritive value apart from producing blood sugar. Potato has various nutrients but is loaded with starch which converts to blood sugar.
We now have a claimed clearer idea how bad carbohydrates exert their toxic action on our body tissues – they raise blood sugar and encourage bad gut bacteria, both actions being related to high blood triglycerides, low HDL, obesity, risk of diabetes and cardiovascular disease. High blood sugar is now suspected to probably be a more toxic and inflammatory agent on blood vessels and other tissues than blood cholesterol.
Unfortunately, some nutritionists and government public health departments are still recommending diets with negligible saturated fat. Recommendations for a “balanced healthy diet” need to stop hiding behind vague generalities and specify what exactly their “balanced healthy” diet consists of.
The most current scientific understanding maintains vegetables, fruits and nuts as the healthiest dietary components, animal products and saturated fat not as evil as previously thought (in moderation), and sugars and refined carbohydrates as the worst component, particularly so if they are forming the diet’s major portion. Although whole grains have got the “thumbs up”, diabetics still need to be careful about portion size because they do produce blood sugar.
The relevant scientific references supporting this feature have been published in a series of articles in The Synapse, a Maltese medical journal. Professor Cilia-Vincenti is a practising pathologist and chairman of the Academy of Nutritional Medicine (UK), a former scientific delegate to the European Medicines Agency, London and Malta university teacher, and pathology services director to a British Healthcare Trust and to the Maltese health service.
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