Hopefully as an astute reader, you are already well aware that saturated fat has never been the villain the media and dietary associations have painted them to be. If any clarification is needed, it is only when dietary sugars combine with saturated fatty acids does it ever present harm. This is because of oxidation of saturated fatty acids. This is why minimal sugar consumption with saturated fats is advised. 
In similar fashion as saturated fat, an omega 6 fatty acid, known as linoleic acid (LA) has been vilified for some time as well, especially in the non-mainstream community. Meanwhile, the mainstream would push the use of processed forms of omega 6, such as margarine, and bottled, processed forms not ideal for human health. Various experts have cried out for many years that too much omega 6 would undermine health. Is this really true?
Is Omega 6 Really Dangerous?
The answer is if the omega 6 is found in the adulterated form (oxidized), processed, denatured form, then yes. However, it is an essential fatty acid, and when consumed in its unadulterated, non-oxidized form, the answer is no, because it is very healthy.
I could never help but notice research that would tip its hand towards the benefits of consuming omega-6 fatty acids over the last two decades. Unfortunately, research rarely distinguished the quality of the oils used. Research on saturated fats had similar problems, sometimes the oils were changed (hydrogenated), oxidized or altered from its natural state.
Most omega-6 oils purchased in stores, sitting on shelves have been heavily processed, bathed in caustic baths in corrosive acids, heated at high temperatures, and stripped of their natural nutrients, therefore adulterated. Further, many omega-6 oils have been processed further by hydrogenation (rendering them into trans-fats), making them even worse.
Maligning an Essential Fatty Acid
While omega-3 fatty acids are also essential, the urgency against the use of omega-6 fatty acids (linoleic acid) has gone too far. As a result, a vast number of those in the natural health movement still subscribe to the notion that omega-6 is unhealthy. There are other factions who swear off polyunsaturated fatty acids (both omega 3 and omega 6) altogether, limiting consumption to 4 grams per day, such as Ray Peat.
These essential fatty acids are only as good as they are unprocessed. Any processing in the way of heat, oxygen, excessive light, hydrogenation (adding hydrogen atoms) is going to undermine health. Few people obtain or utilize omega 6 from unadulterated sources, and instead consume mostly oxidized, adulterated forms.
Why Unadulterated Omega 6 is Healthy
Recently, the differences of effects of both adulterated and unadulterated forms of omega 6 on cardiovascular disease were examined.
Omega 6, or rather the primary fatty acid, known as linoleic acid (LA) is an essential precursor of both pro and anti-inflammatory substances, a blood vessel lubricator, prostaglandins (hormone-like function), and much more. Linoleic acid is abundant in the skin and the nervous system. In fact, the skin contains almost one thousand times more omega 6 than it does omega 3 fatty acids in them. That’s right, there’s virtually no omega 3 found in your skin.
Omega 6 fatty acids produce the prostaglandin PGE1. Part of the controversy about LA in general is that it is the precursor for arachidonic acid (AA), an omega-6 derivative. While that is accurate, AA is a precursor for a chain of pro-inflammatory molecules. However, keep in mind that arachidonic acid is absolutely necessary for normal body physiology, in fact without it, the body cannot produce prostacyclin, which is the most important vasodilator and vascular protective substance your body makes.
To fully understand the magnitude of the importance of prostacyclin, think of all of those people who died of cardiovascular deaths due to taking the drug Vioxx. Vioxx is a COX-2 inhibitor, and literally cuts off prostacyclin. Prostacyclin is a very potent anti-inflammatory.
Startling Proof on the Effects of Unadulterated Linoleic Acid
In a study using a blend of unsaturated fatty acids, rich in omega 6, derived from seed oils such as safflower and pumpkin seeds, some remarkable results were found. The study was conducted measuring arterial flexibility, revealing significant differences in biological age compared to physical age.
The study utilized photoplethysmography (PTG) to measure the difference in arterial flexibility between subjects taking unrefined essential fatty acids. Photoplethysmography can be used to gauge arterial hardening. The result of the measurement can then be compared to a specific group for comparison or to provide a biological age of person based on the degree of hardening.
Thirty-five patients were were measured with PTG and then were subsequently given unadulterated essential fatty acids (safflower, pumpkin and flax seed oils) for 24-months.
The result after the 24 months? An impressive 73% had an average improvement of 9 biological years in their arterial flexibility. 
The beneficial health effects of omega 6 polyunsaturated fatty acids, particularly linoleic acid (LA) in its unadulterated form is protective of heart disease and should be consumed as part of a healthy diet. Of course, in stark contrast to the unadulterated form, plenty of evidence exists that adulterated forms of linoleic acid, especially in the hydrogenated vegetable oil form, is highly atherogenic (promotes arterial plaque) and should be excluded from the diet. The adulteration of the natural omega-6 fatty acid, LA, has contributed to mixed findings regarding the effects of this fatty acid on cardiovascular health. Thus, it is critical that the source of LA be taken into account when drawing conclusions about the physiological effects of this fatty acid. , 
What is Healthy Omega 6 Oil?
A healthy omega 6 oil is one that has not been processed, it must be unrefined and raw, preferably organic. For example, if nuts or seeds are heated (roasted), the omega 6 fatty acids within them have just been adulterated. Therefore, one should consider raw, organic nuts and seeds.
. Iowa Study; Peskin, B.
. Food and Nutrition Sciences, 2013, 4, 76-85
. J Integr Med. 2013 Jan;11(1):2-10.