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Why is fat consumption important?

Why is it important to think about fats?

Every year there is a greater understanding of the determining role of EPA and DHA fatty acids on our health. It is now known, for example, that people with the highest blood levels of EPA and DHA combined were 10% to 17% less likely to die prematurely and 9% to 21% less likely to die. die from cardiovascular disease, compared to those with the lowest levels” (see study).

What makes these fatty acids interesting is that their effects are not just on a mechanism of action, but have pleiotropic influences. EPA, in particular, has positive effects on lipid metabolism, inflammatory processes, oxidative load, platelet aggregation, cell membrane functionality, vascular health, coronary health, and the immune system, both innate and adaptive. (see study).

In this review we will learn what exactly EPAs are, when the first studies on their impact on health begin, and we will delve into their most important effects.

Before starting, it is important to clarify a series of concepts
Fats are one of the 5 groups of macronutrients, made up of:

fats
protein
carbohydrates
ketones
Alcohol

In turn, according to its chemical structure, we find different types of fat:

Saturated fats

Made up of a single long chain of carbon atoms, all joined by single bonds. The easiest way to detect saturated fats is that they are solid at room temperature. Some examples of foods with saturated fats are meat, dairy or coconut oil.

Structure of saturated fats. Omega 3

Unsaturated fats

Made up of at least one (monounsaturated) or more (polyunsaturated) double or triple bonds. Polyunsaturated fats are liquid at room temperature and even when you put them in the fridge

Among the different types of polyunsaturated fats we find omega-3:

The first double bond is in the third position, counting backwards from the final carbon.

Omega-3 fatty acids include alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is found primarily in vegetable oils such as flaxseed, soybean, and canola oils. DHA and EPA are found in fish and other shellfish. The human body can convert some ALA to EPA and then to DHA, but the process is very inefficient, with most healthy adults converting only about 5% to 10% to EPA and 2% to 5% to DHA .

The point is that while the fatty acids EPA and DHA fulfill many vital functions, ALA, on the other hand, does not, and since its structure is similar, it competes for a place in the cell membrane. Hence, it is important to consume omega-3 directly in the form of EPA and DHA.

The difficulty in the conversion, added to its particularly important role in human health, has led to consider EPA and DHA oils as essential. That is, they must be included from the diet, since human beings are unable to manufacture them in adequate quantities to maintain optimal health.

Why has it taken so long to highlight the beneficial role of some types of fats?

Despite:

The brain is 60% fat.
The main material of all the membranes of the 37 trillion cells in our body is essentially fat.
Fat is the raw material for multiple hormones, essential substances for proper body function (estrogens, progesterone or anti-inflammatory substances such as lipoxins, for example).
Many essential vitamins are consumed along with fat, as they are fat-soluble such as vitamin A, D, K, or E.
For a long time, fat has been demonized and considered the macronutrient responsible for many of the ills of human beings.

This is mainly due to 2 factors:

The deliberate action of the sugar companies to influence the scientific and political debate: As the article published in the journal JAMA Internal Medicine in 2016 shows, the food industry influenced to question the harmful role of sugar and point out as the only culprit from metabolic disorders to fat (study).
The food pyramid: designed by the US department of agriculture (not the health department or anything like that…) where grains are at the bottom of the pyramid and we don’t find nutrients with a good nutritional density until the top of the pyramid (of crazy people).
Correlation studies between blood lipids and cardiovascular events (I’ve already told you a lot about it). Remember that correlation is not causation.

88% of North Americans test positive for one of the criteria associated with metabolic syndrome.

If we continue at this rate, in 30 years, one in 3 people will suffer from diabetes.

In short, we must be aware that the industry, with premeditation and treachery, has confused us so that we consume its products, giving it absolutely the same if this made us sick. Even today you can still find messages like “Glucose is the only fuel that can feed and energize the cells of the brain and muscles. Without carbohydrates the body does not function properly«.

Therefore, to delve into the effects of an essential fatty acid such as EPA, we must destroy the belief that fat per se is bad. Let’s understand that encompassing all fats in the same bag is an aberration and let’s put fats in their rightful place.

The beginnings of research with Omega-3

Fifty years ago, Danish scientists Hans Olaf Bang and Jørn Dyerberg embarked on an icy voyage to the remote coastal regions of northwestern Greenland.

They wanted to understand why the Inuit, the indigenous people of the area, had the world’s lowest incidence of cardiovascular-related deaths despite their high-fat diet, rich in seal meat and oily fish.

Bang and Dyerberg’s research revealed that the average Inuit had lower concentrations of triglycerides and lipids than the average Dane. But the concentrations of Inuit were also lower than those of their Inuit peers living in Denmark, suggesting that environmental, rather than genetic, factors were at play.

Further investigation revealed that Inuit living in Greenland had high blood concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), a pair of long-chain polyunsaturated fatty acids. Bang and Dyerberg posited that these fatty acids, commonly known as omega-3s, were the secret to Inuit health. Although the study’s claims about heart disease rates in the Inuit have since been disputed, those early findings provided a catalyst for a vast field of research that continues today.

Omega-3s had also caught the interest of scientists in the United States, including Dr. William (“Bill”) Connor, a pioneer in the fields of lipid nutrition, cholesterol metabolism, and atherosclerosis. Dr. Connor encouraged Dr. Harris to pursue the study of omega-3s, launching a study career spanning 40 years and 300 publications (link). Connor and Harris were the initiators of an avalanche of articles on the role of different omega-3s on our health.

Infographic of the carbon structures of Omega-3 fats Main benefits of EPA on our health.

1. Lipid metabolism:

Clinical studies have shown that high doses of EPA are associated with a normalization of lipid panels associated with arteriosclerosis. On the one hand, they reduce circulating non-high-density lipoprotein cholesterol (non-HDL-C), very low-density lipoprotein cholesterol (VLDL-C), and triglycerides (study, study). In turn, EPA also reduces apolipoprotein B and apolipoprotein CIII. Lipoproteins highly linked to vascular wall damage (study).

The mechanism of EPA-mediated triglyceride lowering is thought to be through reduced hepatic production of VLDL lipoproteins, including a reduction in both particle size and number (study).

Therefore, EPAs help maintain balanced levels between the different forms of cholesterol and keep triglycerides at adequate levels.

2. Inflammation:

EPA has been shown in multiple clinical trials to reduce key markers of acute inflammation, including high-sensitivity C-reactive protein (study).

EPA plays a fundamental role in the regulation of inflammation through different pathways:

Using the enzymes that are responsible for producing inflammatory substances to generate anti-inflammatory metabolites.
Being a precursor of highly anti-inflammatory metabolites such as resolvins RvE1-RvE3. These metabolites play an active role in the resolution of inflammation and the regulation of the inflammatory response. Maresins and protectins produced from EPAs have also been observed.

3. Antioxidant Effects:

EPA stimulates the action of two antioxidant enzymes: Paraoxonase 1 and 2 (study). This effect is particularly relevant in the modulation of the oxidation of circulating blood lipids. Precisely the damage to the vascular wall that we observe in cardiovascular diseases is caused by these oxidized lipids that circulate in the blood. Hence, this antioxidant effect is relevant in the prevention mechanisms of cardiovascular pathology.

4. Antiplatelet effects:

EPA induces the production of prostracyclin 3, a substance that modulates platelet aggregation. In turn, the production of resolvin 1 from EPA also has regulatory effects on platelets (study).

Therefore, EPA directly influences the correct coagulation of the blood, avoiding unnecessary thrombi.

5. Functionality and stability of the cell membrane:

EPA and DHA can be incorporated into the cell membrane, where they have the potential to affect its structure and function (study). One of the most important functions is its ability to alter membrane fluidity. EPA in particular helps preserve membrane structure, promotes normal cholesterol distribution, and inhibits lipid oxidation and cholesterol crystal formation. In addition, it facilitates the translation of signals from the cell membrane to the interior of the cell (study).

6. Regulation of the innate and adaptive immune system:

EPA is a precursor of metabolites such as 1-2-3-4 resolvins, 18-hydroeicosapentaenoic acid or 12-17-18 epoxyeicosatetraenoic acid.

All these metabolites perform normalizing functions on different cells of the immune system:

Resolvins 1 -Inhibits neutrophil infiltration
-Increases apoptosis of neutrophils through phagocytosis
-Improves the scavenging ability of macrophages
-downregulates inflammatory cytokines
Resolvins 3 -Inhibits neutrophil infiltration
-Improves the scavenging ability of macrophages
-Inhibits infiltration and migration of neutrophils
Resolvins 4 -Increases efferocytosis of macrophages
-Inhibits neutrophil infiltration
18-hydroeicosapentaenoic acid -Decreases fibroblast activation
-Reduces monocyte adhesion and cardiac remodeling
-Improves mitochondrial function
17-18 epoxyeicosatetraenoic acid -Prevents mast cell degranulation
-Limits adhesion of monocytes to endothelial cells
-Inhibits migration of neutrophils
-downregulates inflammatory cytokines
12-OH-epoxyeicosatetraenoic acid. -Inhibits neutrophil infiltration
-Decreases neutrophil chemotaxis
-Downregulates the accumulation of inflammatory cells.

Conclusion

There is increasing evidence that EPA has pleiotropic actions beyond the known lowering of triglycerides.
Its effects associated with the regulation of multiple body processes places it as a very relevant substance for human health.
Its semi-essential character requires its direct consumption through fish or shellfish.
Many of the therapeutic effects described require high doses of EPA, which range between 500mg and 8 grams per day.
Most of the current studies show effects in a relatively short time with doses between 2 and 4 grams per day.