For decades, we have been told to load up on this “healthy” fat (and avoid trans-fat and saturated fat).

And while this may be okay advice for people under the ages of 50, a new study published in the FASEB Journal has shown that if you’re older than that, you need to be very careful.

This is as this fat destroys your immune system and leads directly to stroke and heart attack.

The researchers split their mice into young and old categories, with the range being approximately two months versus 18 months old.

They gave all of them a high omega-6 vegetable oil diet and then triggered heart attacks or other heart-injuring events to see how their bodies would respond.

Examples of high omega-6 oils include sunflower and safflower oils, both oils that are frequently used for cooking.

As expected, the young mice had a tendency to survive these adverse heart events while the older ones often died.

And they investigated the mice, they found that the bacterial profiles in their intestines had changed completely.

Both the old and young mice had some factors in common:

Specifically, they developed a lot more bacteria from the phylum Firmicutes group, a type of bacteria that has previously been associated with obesity, diabetes, and system-wide inflammation.

On top of that, both groups experienced a huge increase in neutrophils, a type of white blood cell that is natively a part of the immune system.

That was the end of the similarities, however.

There is another type of white blood cell used by the immune system is called leukocytes, and the spleen is normally a rich reservoir of these leukocytes.

When our hearts are injured by heart attacks or other terrible heart events, our spleens release these leukocytes that then rush to our hearts to repair the tissue and manage the inflammation at the injury site.

While this is what happened to the young mice in this study, this mechanism did not work with the old mice.

The two types of white immune blood cells, neutrophils and leukocytes, thus need to be carefully balanced for our immune systems to work properly.

But in the case of the old mice, the increase in neutrophils caused by the high-fat diet completely overwhelmed the leukocytes, leaving the latter incapable of doing their job in repairing the heart.

They also found that the old mice had structural deformities in their spleens.

In other words, during the point in which the inflammation was increased by high fat intake, intestinal phylum Firmicutes, and heart injury, the spleens of the old mice were impaired and could not release enough leukocytes to resolve the inflammation.

Medical scientists call this a non-resolving inflammation and it is ultimately the cause of heart failure.

If this study applies to humans too, then it shows why old people should pay even more attention to eating less omega-6 vegetable oils than young people, as their bodies might simply not repair heart damage if it occurs.

But the consumption of omega-6 is only one piece of the puzzle, the real danger lies in one food item that is never listed on the food label. This is the single biggest cause of cholesterol plaque build-up in your arteries…