FATS, OILS and FATTY ACIDS

November 18, 2021from admin

Fats and oils are neutral compounds from:

trivalent alcohol glycerol
plus 3 fatty acid molecules

This combination is also called "triglycerides" due to the three FA molecules. These are broken down by special enzymes, the so-called lipases, into glycerol (which then goes into the blood) and fatty acids.

Fats and oils have the same chemical structure. However, oils contain shorter fatty acids and, unlike fats, are therefore liquid at room temperature.

Cis and trans fatty acids

Natural fatty acids are mostly in the so-called "cis" form, i.e. the carbon chains are on one side of the double bond (three-dimensional), which means that the membrane structures have greater elasticity. In contrast, the hardened, so-called "trans" fatty acids are usually artificially produced (see below). As a result, the fatty acids are two-dimensional and more rigid, no longer liquid and spreadable. However, this reduces the elasticity of the membrane structures.

Trans fatty acids increase the "bad" LDL and lower the "good" HDL cholesterol and thus increase the risk of thrombosis. Their incorporation into cell walls leads to a rigid cell membrane and thus impedes organ functions.

Typical foods that may contain trans fat are: margarine, mayonnaise, cookies, savory snacks, cakes, chocolate filling, candy and convenience foods.

"Artificial trans fats are considered a risk factor for cardiovascular disease. Consuming these substances increases the level of LDL cholesterol in the blood. They "may not generally be considered safe," the Food and Drug Administration said.

(Source: Die Ärzte-Zeitung online, November 11, 2013)

Saturated and unsaturated fatty acids

The fatty acids are divided into

saturated fatty acids
monounsaturated fatty acids
polyunsaturated fatty acids (e.g. omega 3, 6, 9 fatty acids)

The "saturation" is defined by the number of C=C double bonds. Saturated fatty acids have no double bonds, monounsaturated fatty acids have one, polyunsaturated fatty acids have several double bonds.

One of the best-known saturated fatty acids are

Lauric acid --> laurel oil, palm oil, animal fats
Myristic acid --> coconut oil, palm oil, animal fats
palmitic acid --> palm oil, cottonseed oil, animal and vegetable fats, beeswax
Stearic acid --> animal and vegetable fats

In the unsaturated fatty acids the position of the double bond is important for the biochemical effect. In the classification, the position of the first double bond from the methyl end (CH3) is determined and then gives the name. I.e. if the first double bond is, for example, in the third position seen from the methyl end, one speaks of "Omega 3" fatty acids.

The two main representatives of polyunsaturated fatty acids are the omega 3- and the omega 6 fatty acids. Both fatty acids are “essential”, i.e. must be obtained from the diet, whereas monosaturated and unsaturated fatty acids are non-essential and can be synthesized by the body

Omega 3 fatty acids

Alpha-linolenic acid (ALA)
V.a. contained in linseed oil, soybean oil, rapeseed oil and margarine
eicosapentaenoic acid (EPA)
V.a. contained in sea fish (salmon, mackerel, herring, sardines, tuna) and algae
Docosahexaenoic acid (DHA)
V.a.found in sea fish and algae

Omega 6 fatty acids

linoleic acid

Contained in thistle, sunflower, soybean, corn and wheat germ oil as well as vegetable and diet margarine
(+) important for skin structure/skin barrier
(-) lowers the "good" cholesterol HDL
(-) can lead to LDL oxidation
Gamma-linolenic acid
is synthesized from linoleic acid in plant leaves, for example, so basically the same effect profile
especially contained in hemp oil, evening primrose oil, borage oil
Arachidonic acid
Occurs primarily in meat (in small amounts also in milk)
(-) when it is metabolized, breakdown products are formed that have an inflammatory effect.

Unsaturated fatty acids are starting materials for eicosanoids ("tissue hormones"), which have important control tasks: in addition to cell division and platelet aggregation (blood clotting), they are primarily involved in inflammatory processes.

Important eicosanoids are

prostaglandins
Prostacyclins
thromboxanes
leukotrienes

Arachidonic acid (the "bad" omega 6 fatty acid) is metabolized into

Prostaglandins 2 series
thromboxanes
leukotrienes 4 series,
...all contributing to acute inflammation!

The omega 3 fatty acid EPA, on the other hand, is metabolized in

Prostaglandins 3 series
Leukotrienes 5 series
E-Resolvine (E1 inhibits the migration of inflammatory cells into the inflamed tissue and the formation of the messenger substance interleukin 12),
...which contribute to the active resolution of the inflammation!

DHA is also metabolized into inflammation-dissolving lipid mediators, especially into protectins and D-resolvins: Resolvin D2 causes endothelial cells to produce nitrogen monoxide, which causes the adhesion of leukocytes and thus their Immigration into the inflamed tissue is prevented.

Despite strong similarities in molecular structure, the biological functions of omega 3 and omega 6 fatty acids are very different:

Omega 3 fatty acids...

… deliver only the “good” eicosanoids and inhibit the formation of “bad” eicosanoids from arachidonic acid
... act

anti-inflammatory
antirheumatic
cardioprotective
promote the intellectual development of the embryo

Omega 6 fatty acids...

... can form anti-inflammatory (linoleic and linolenic acid), as well as pro-inflammatory (arachidonic acid / see above) and even carcinogenic eicosanoids, whereas omega 3 only forms the "good", anti-inflammatory eicosanoids (+/-)
CAUTION: If large amounts of "good" omega 6 fatty acids (linoleic/linolenic acid) accumulate, more pro-inflammatory arachidonic acid can be formed! Therefore, the ratio of omega 6 to omega 3 is important. In addition, the body needs the enzymes delta-6 and delta-5 desaturase to convert plant-based ALA into EPA/DHA. However, these two enzymes are also required to convert the omega 6 fatty acid linoleic acid into other omega 6 fatty acids. By reducing the omega 6 fatty acid content in food, the body has more enzymes available to convert ALA into EPA/DHA.
In the Stone Age, the ratio of omega 6 to omega 3 was 4:1.Due to cattle breeding, fattening and farming, the ratio of omega 3 fatty acids has continued to deteriorate and is now ~20:1 in western societies (the DGE recommends a ratio of 5:1)!

… promote the formation of hemoglobin (hemoglobin is responsible for the transport of oxygen and CO2 in the blood) (+)
… have an important function during the division of the cell nucleus (mitosis) by ensuring the stability of the chromosomes in the cell nucleus (+)
… are important components of the double membrane of all cells and cell organelles
... accelerate the breakdown of lactate (lactate is a metabolic product of glycolysis; it is produced by reducing pyruvate to lactate; excess lactate makes legs heavy and muscles tired, for example, because they are acidic) (+)

Possible consequences of a lack of fatty acids

Omega 3 (essential)

Rheumatoid inflammation
Retarded embryonic development
Sensitivity disorders (MS!)
Learning and visual impairments
Growth disorders
Dry skin

Omega 6 (essential)

Eczema
Hair loss
susceptibility to infection
Delayed wound healing
Growth disorders

The European Food Safety Authority (EFSA) recommends a daily intake of 250 mg EPA and/or DHA daily (as of March 2010).

DHA and EPA should always be taken with the highest-fat meal.

In recent years, further studies have shown that administration of >2 g EPA/DHA per day is required for the prevention and therapy of common clinical pictures:

2.2 g for good memory and prevention of Alzheimer's (Charité study, published in the Journal of Alzheimer's Disease 02/2016)
4 g to achieve a high anti-inflammatory effect (Yates, Calder et al. 2014)
2.7g for rheumatism and gradual reduction in nonsteroidal anti-inflammatory drugs (NSAIDs) (Lee YH1, Bae SC, Sng GG., 2012)
3-4 g in non-alcoholic fatty liver (Byrne, et. al. 2014 / Stephen, et. al. 2015)

The misconception that alpha-linolenic acid ALA can be converted into EPA and DHA by the body and that vegetarians and vegans can only meet their EPA and DHA requirements by consuming linseed oil, for example, is very widespread. ALA can only be converted to a fraction of about 5% into EPA and ~0.5% into DHA. It is therefore not possible to get a sufficient supply of the biochemically so without consuming fish or algae oil important DHA and EPA fatty acids!

Health Claims

The scientifically proven effects of a dietary supplement are referred to as "health claims". These are as follows for DHA and EPA:

EPA and DHA contribute to normal heart function
EPA and DHA contribute to maintaining normal blood pressure
EPA and DHA contribute to the maintenance of normal blood triglyceride concentrations
DHA contributes to the maintenance of normal brain function
DHA contributes to the maintenance of normal vision
DHA contributes to the development of vision in young children
Maternal intake of docosahexaenoic acid (DHA) during pregnancy and lactation contributes to the normal brain development of the fetus and the breastfed child
Maternal intake of docosahexaenoic acid (DHA) during pregnancy and lactation contributes to the normal development of the eyes of the fetus and the breastfed child.

Conclusion

Finally, it remains to be noted that

the EPA and DHA content of an omega 3 dietary supplement is crucial for its health-promoting effects
the highest values for omega 3 from high-quality fish oil are 500 mg EPA and 250 mg DHA per 1000 mg fish oil (omega 3, 50/25 EPA/DHA) .
Algae oil, especially with EPA, which is very important for the anti-inflammatory effect, for example, has significantly lower values.