Generality
What are Omega 6s?
Omega 6s are a family of lipids , to which the essential fatty acid linoleic acid (LA) and the semi-essential gamma linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA) belong.
Does omega 6 increase or decrease cardiovascular risk ?
Omega 6 are essential and semi-essential fatty acids that play a promiscuous role on cardiovascular risk:
- Positive role: they improve some metabolic parameters, above all lipemia and in particular cholesterolemia, reducing the cardiovascular risk.
- Negative role: it is possible that some of them, if present in excess and for the reasons that we will explain below, increase cardiovascular risk.
Omega 6 and Cholesterol
The right dose of omega 6 decreases cardiovascular risk
is observed , due to the decrease of the bad one or LDL (Low Density Lipoprotein). In fact, there is no real bad cholesterol ; cholesterol is “more or less” all the same (let’s leave out the details of a purely chemical nature). The intake of omega 6 does not reduce the production of cholesterol by the liver , but the synthesis of LDL. LDLs are particular transporters of fats in the blood , which carry lipids from the liver to the suburbs.If in excess, peripheral cholesterol tends to deposit in the arteries , participating in atherosclerosis . This is why, by reducing LDL, omega 6 can help reduce cardiovascular risk.
The scientific evidence supporting a possible improvement effect of omega 6 on the synthesis of good cholesterol or HDL (High Density Lipoprotein) is less evident, which sometimes even seem to decrease.
On the contrary, HDL increases significantly thanks to motor physical activity .
- To obtain the maximum metabolic result from the consumption of omega 6 it is necessary that, together with the omega 3, they replace the so-called ” bad fats ” ( saturated , hydrogenated and especially in trans conformation).
- Furthermore, as we will see later, it is essential to respect the “overall caloric constraint”. A diet that is too rich in fat predisposes to overweight and, even if composed of excellent quality lipids, risks nullifying the protective effect of the latter on cardiovascular risk.
Linoleic acid, as well as omega 3:
- Decreases blood pressure
- Decreases the production of PAI (antifibrinolytic molecule)
- Increases insulin sensitivity
These are all aspects that decrease cardiovascular risk.
Omega 6 and Inflammation
An excess of omega 6 is considered potentially harmful to the body; let’s see why.
Excess arachidonic acid increases inflammation and cardiovascular risk
The excess of AA seems to alter the inflammatory balance of the body.
AGEs are responsible for the production of eicosanoids, some of which are anti-inflammatory (vulgarly called good) and some pro-inflammatory (called bad).
While omega 3 and some omega 6 (GLA) produce good anti-inflammatory eicosanoids , certain omega 6 and in particular arachidonic acid are precursors of bad pro-inflammatory ones (inflammatory cascade). Increased inflammation is a factor that greatly increases cardiovascular risk.
Omega 6s damage Omega 3s
The excess of omega 6 decreases the effect of omega 3 and increases the cardiovascular risk
An excess of omega 6, especially linoleic acid, is harmful for the metabolism of omega 3.
The essential fatty acids (AGE omega 6 and omega 3) are processed in the cells thanks to the effect of the same enzymes . Therefore, the excess of omega 6 tends to “occupy” all these biological catalysts, affecting the metabolism of omega 3 (for example, it reduces the production of eicosapentaenoic acid EPA and docosahexaenoic acid DHA). Furthermore, omega 3s are less present in the diet.