The bar charts represent the percentages of fatty acids (What is a fatty acid?) in fats and in oils.
The chart bars for saturated fatty acids (list of saturated fatty acids) are blue, the chart bars for monounsaturated fatty acids (list of mono-unsaurated fatty acids) are yellow, the chart bars for polyunsaturated fatty acids from the omega-6 essential fatty acids (n-6 EFAs) (list of omega-6 fatty acids) and the omega-3 essential fatty acids (n-3 EFAs) (list of omega-3 fatty acids) respectively red and green.
The digits at the bottom of the charts represent the number of carbon atoms (the digits before the dot) and the number of double bonds (the digit after the dot) in the fatty acid molecule. The data is from the United States Department of Agriculture (USDA)
ANIMAL and HUMAN FAT
Animal and human fat contains saturated (blue), monounsaturated (yellow) and poly-unsaturated (red and green) fatty acids
The similarity between human fat, animal fat and butter is striking.
Olive oil contain mainly monounsaturated fatty acids (yellow) and some saturated (blue) and
polyunsaturated (red and green) fatty acids.
Coconut oil contain mainly saturated fatty acids (blue) and some monounsaturated (yellow) and
polyunsaturated (red and green) fatty acids.
Palm oil contain in almost identical proportion saturated (blue) and monounsaturated fatty acids
(yellow) fatty acids and some polyunsaturated (red) fatty acids.
Vegetable oils contain much more unsaturated fatty acids and less saturated fatty acids than human or animal fat and in contrast with human and animal fat where unsaturated fatty acids are predominantly omega-9 fatty acids (yellow bars in the charts), the unsaturated fatty acids in vegetable oils are mainly omega-6 essential fatty acids (red bars in charts).
Furthermore, vegetable oils are totally deprived of any long chain essential omega-3 fatty acids (20.5 and 22.6 in the charts)
THE VERY PARTICULAR CASE OF CANOLA (rapeseed oil)
- As you can see in the first chart hereunder, Canola oil HAD an omega-6 (red bar in the chart) to omega-3 (green bar) ratio of 2 to 1. However, since omega-3 fatty acids, with their numerous double bonds, are more sensitive to degradation by oxidation the producers of Canola oil have selected plants to obtain rapeseeds with a reduced omega-3 content.
This was announced as an improvement of the product’s quality by extension of shelving life and better resistance to high temperature (with no consideration for the health of the consumer).
- The second chart shows the Canola oil actual omega-6 (red bar in the chart) to omega-3 (green bar) ratio of more than 15 to 1.
Canola oil, although it contains less omega-6 than other vegetable oils, is no longer better at helping restore the omega-6 to omega-3 ratio in the diet.
Add to it that, according FDA regulations, it still may contain up to 2% of the insecticide Erucic acid (22.1 in the chart).
Indeed, Canola oil is made of rapeseed oil by chemically reducing its content of 30-60 % of erucic acid (22.1 in the chart)
to the legal maximum of 2 %.
The Environmental Protection Agency (EPA) still lists Canola oil as a pesticide.
Consumer acceptance of canola oil represents one in a series of victories for the food processing industry, which has as its goal the replacement of all traditional foods with imitation foods made out of products derived from corn, wheat, soybeans and oil seeds. Read "The Great Con-ola, written by Sally Fallon and Mary G. Enig, Ph D
2 - A GLIMPSE at the HISTORY of MARGARINE
Please visit the Cyberlipid Center webpage describing the history of margarine, then come back to this page.
1 - From 1869 to 1911 margarine is a natural product
At the Cyberlipid page you have read that margarine was invented in 1869 to compensate for the scarcity of butter and animal fat (beef tallow and lard) and that margarine was initially made of beef tallow and skimmed milk and that the first addition to the original margarine was vegetable oils and fats, coconut being the maine source.
The succes of the product was overwhelming.
At the Ciberlipid Webpage you have also read that the anual production of margarine was already about 100,000 tons in 1875, only six years after its invention. In the begining of the twentiest century the production reached more than 500,000 tons/year and the margarine industry had to find other supply source. Around that time chemists had found a way to change oils into fats by hydrogenation.
2 - Starting in 1911 margarine is made from whale oil
The next event was whale oil and this switch is a tipping point in human fat consumption. The industry could use oil to make margarine and spreads only after hydrogenation of the oil. Why?
Becaue oils are liquid at room temperature. "The goal of partial hydrogenation is to add hydrogen atoms to cis-unsaturated fats, making them more saturated. These saturated fats have a higher melting point, which makes them attractive for baking and extends their shelving life. However, the catalyst also catalyses a side reaction that isomerizes some of the cis-unsaturated fats into trans- fats instead of hydrogenating them completely" (From Wikipedia) Read more
3 - In 1950 the industry starts using vegetable oil
Whale oil could no longer be used after 1950 owing to the international whale hunt regulation. The margarine industry had to find other sources. They chose vegetable oils. After all, they had already changed whale oil in fat and they could now use their skills to hydrogenate vegetable oil as well. As a result, since 1950 margarine has been produced all over the world mainly from various hydrogenated vegetable oils,
A Big Boost from Medicine
It is also in the early fifties that Medicine invented its saturated fat and cholesterol myth. The oil industry jumped in that wagon advertising their products as free of cholesterol and made solely of unsaturated fat. Indeed vegetable oils (examples are corn oil, sunflower seeds and soya bean oils) contain more than 80 percent unsaturated fatty acids (yellow, red and green bars in the above charts).
The switch from animal fat to vegetable oil has completely changed the composition of fatty acids in our diet.
The switch has resulted in a 65% drop in saturated fatty acids (inclusive the suppression of the medium chain
fatty acids), a 45% drop in mono-unsaturated fatty Acids, and a sixfold increase in omega-6 essential fatty acids.
The switch also suppressed the omega-3 essential fatty acids in the diet while multiplying by a whooping 150
the trans fatty acid content of the diet.
3 - The HEALTH CONSEQUENCES of an EXCESSIVE VEGETABLE OIL CONSUMPTION
The switch from animal fat to vegetable oils is responsible for three changes in the fatty acid composition of our diet;
- (A) An excess of trans fatty acids
- (B) The Imbalance of the Omega-6 to Omega-3 Essential Fatty Acid Ratio.
(c) The absence of medium chain fatty acids.
Each of those changes has specific consequences for our health.
A - Excess of Trans Fatty Acids
Trans fats are poison
(quote): "Since the early 1990s, scientific evidence has been pouring in about the many dangers of trans fats found in margarine – as well in other artificially created fats like vegetable shortening and partially hydrogenated vegetable oil" (end quote) Read more
Trans fats are poison because the trans fatty acids (TFAs) they contain don't fit into our biochemistry. Trans fats are incriminated in the obesity, cardio vascular, allergy and auto-immune epidemics of the twentieth century. Trans fat are the worse component of our "chemical food"
Trans fats started to invade the American diet in 1911. Since then and STILL TODAY Margarine, spreads and hydrogenated oils are the main sources of trans fats.
Fat in our actual diet contains up to 3.5% of trans fatty acid and (quote): "The major sources of trans-fatty acids are bakery foods (33% of total trans-fatty acid intake), fast foods (12% of total), breads (10%), snacks (10%), and margarines/shortenings (8%)."(end quote). more .
Health Consequences of the Excess of Trans Fatty Acids in the diet
Our biochemistry has never been exposed to such high levels of TFAs and is unable to separate TFAs from the other fatty acids.
The health deterioration caused by TFAs result from their indiscriminated incorporation into fat molecules and into the phospholipids of the cell membranes and of the membranes of the mitochondria (the power units of the cells)
The fatty acids we find in food become fat molecules and form the bulk of the membrranes of all our cells and of all the cell organelles
Our Fig. 3 - Cell membranes are made of a double layer of fatty acids attached two by two
to a phosphoric acid molecule (the yellow spheres in the drawing, forming phospholipids
The presence of TFAs in cell membranes disturbs the activity of the functional molecules embedded in the membrane.
1 - Examples of functional molecules are the calcium entry channels and the calcium exit pumps.
In the membranes of heart muscle cells the calcium entry channels are activated by nerve impulse. Each new impluse allows the entry of an appropriated and small volume of calcium triggering cell activity. TFAs accumulation in the cell membrane makes the cell's calcium entry channels "leaky" allowing excessive calcium to enter the cell. Associated or not with a calcium exit pump slowdown (resulting from a long chain omega-3 essential fatty acid deficiency in the same cell membrane) calcium accumulation shall disturb the cell functions and eventually kill the cell. This mechanism explains how an excessive level of TFAs in the diet is associated with a greater risk of fatal ishaemic heart disease (IHD) and sudden cardiac death. It is estimated that dietary TFAs from partially hydrogenated oils may be responsible for between 30,000 and 100,000 premature coronary deaths per year in the United States.
Leaky calcium entry channels also accounts for the "Alzheimer's Calcium Hypothesis" formulated by a biologist of the University of Toronto.
In an animal experiment trans fat incorporation in the diet was found to impair brain function: (quote) Experiments with middle-aged rats, roughly equivalent in age to a 60-year-old person, showed that after only eight weeks of eating high fat foods, those on a high trans fat diet could not perform simple memory tasks. (end quote)
2 - Other functional molecules embedded in cell membrane are the glucose receptors
Glucose receptors exist in all cells and are activated by the hormone insulin. TFAs in cell membrane disturb the function of the glucose receptors resulting in decreased insulin-stimulated glucose entry and disrupting cell's functions. Food glucose tends to stay in circulation triggering in response a higher insulin secretion. Excess TFAs in the diet has been linked to diabetes type II and since brain cells thrive on glucose only to Alzheimer's disease as well.
We hypothesize the reduction of glucose metabolism described by Lisa Mosconi in AD patients is related to the presence of an abnormal high level of trans fatty acids in the brain cell mitochondrial membranes where the concentration of trans fatty acids may exceed their concentration in the diet. Read more about the devastating effect of trans fatty incorporation into cell membranes
Trans fats are also incriminated in the obesity, cardio vascular, allergy and auto-immune epidemics of the twentieth century. Trans fats are the worse of our "chemical foods".
B - The Imbalance of the Omega-6 to Omega-3 Essential Fatty Acids Ratio in the Diet
One hundred years ago an american was consuming on average 1 pound of vegetable oil per year (1/4 of a teaspoon per day). Today an american consumes 40 pounds per year (almost 2 fl.Oz per day). 50 times more.
Since 1950 our diet contains an excess of linoleic acid
Fig. 4 - Vegetable oils contain up to 60% of linoleic acid (red bars) the 18-2 omega-6 essential fatty acid
(the precursor of cell activity stimulating messenger molecules) while human fat contains only 8% of it.
Linoleic acid (the red bars in the charts) is an essential fatty acid. Essential Fatty Acids (EFAs) are fatty acids we cannot make and have to find in our food. There are two EFA families. The omega-6 (n-6) and the omega-3 (n-3) EFA families. Linoleic acid is a fatty acid from the omega-6 family.
Our biochemistry uses n-6 and n-3 EFAs to make active molecules that govern cell activity. With n-6 EFAs we make messenger molecules (prostaglandins) that stimulate cell activity, with n-3 EFAs we make messenger molecules that slowdown cell activity. Cell activity and the resulting good health of our whole body depends on the balance between the production of the two types of messenger molecules and since we cannot make EFAs and have to find them in food, health also depends on the balance of the n-6/n-3 EFAs ratio in the diet.
With animal products as the sole source of fat, the n-6 to n-3 ratio in the diet was about 2 to 1. Since the switch to vegetable oil with its huge linoleic acid content and the increase of vegetable oil consumption, the n-6 to n-3 ratio of the American diet has climbed steadily reaching today a whooping 20 to 1 instead of the recommended ratio of 2 to 1.
- The Health Consequences of the Imbalance of the Omega-6 to Omega-3 Essential Fatty Acids Ratio in the Diet
The active molecules (prostaglandins) our metabolism makes from n-6 EFAs increase blood coagulation, stimulate inflammation and immune reaction. The prostaglandins made from n-3 EFAs maintain blood fluidity, reduce inflammation and immune reaction.
Since our diet is the sole source of n-6 and the n-3 EFAs blood coagulation, inflammation and immune system activity are closely related to the omega-6 to omega-3 ratio in the diet.
When vegetable oils were introduced there was no interest for the n-6 to n-3 ratio in the diet because at that time no distinction was made between mono-unsaturated fatty acids (yellow bars) and poly-unsaturated fatty acids, the essential fatty acids we cannot make (red and green bars). Mono-unsaturated fatty acids and poly-unsaturated fatty acids were all considered "healthy unsaturated".
The differences between mono-unsaturated fatty acids and poly-unsaturated fatty acids, the distinction between the poly-unsaturated fatty acids n-6 and n-3 and the significance of the n-6 to n-3 ratio in the diet is much more recent than the introduction of vegetable oil.
It is only in 1999 (four decades after the shift to vegetable oil) that the National Institute of Health (NIH) started sponsoring conferences on the role of EFAs in health and disease. The excessive vegetable oil consumption also favors allergy and auto-immune conditions
Aside from undue blood coagulation and excessive inflammation and immune reaction , the introduction of a massive dose of linoleic acid in the diet has also significantly increased the exposure of cell and mitochondrial membranes to oxidative stress. Indeed, animal fat contains about 45% of fatty acids with one double bond and less than 10% of fatty acids with more than one double bond. In contrast, vegetable oil has 20 % of fatty acid with one double bond and about 60% of fatty acids with each two double bonds.. The double bonds are the weak spots in a fatty acid molecule. Double bonds are the structures where oxidative damage occurs.
The switch from animal fat to vegetable oil resulted in more than a 100 percent
increase of weak spots in mitochondrial membranes and consequently in a more
than 100 percent increase of mtDNA exposure to oxidative damage.
The greater exposure to oxidative damage of brain mitochondria since several generations may well be another factor of the epidemic development of Alzheimer disease in our population.
C - Absence of Medium Chain Fatty Acids
The Medium Chain Fatty Acids (MCFAs) are Caproic, Caprilic and Lauric acid, saturated fatty acids with respectiverly 8, 10 and 12 carbon atoms.
MCFAs like most fatty acids come under the form of triglycerides. However MCFAs are absorbed directly in blood circulation instead of having to transit through the lymphatic system, like longer chain fatty acids. Read more
The benefits of MCFAs in the diet becomes increasingly evident as research on their properties progresses. (More to come)
We may well be on the dawn of a public awareness for MCFAs comparable to the situation of the omega-3 EFAs about 12 years ago
Lauric acid may soon become the next essential fatty acid since mamals can only produce it while lactating
Copyright 2007-2010 Edmond Devroey MD