Heart Disease and LDL

Heart disease is the number one killer in America, and LDL cholesterol has gotten most of the blame. But for the last 40 years, researchers have known that oxidized LDL, not LDL, is the true villain implicated in heart disease. Linoleic acid is the most abundant fat found in atherosclerotic plaques. It causes oxidation of LDL, and this has been known since at least the 1960s. 1 It is now well established that LDL can undergo oxidation when too much linoleic acid is present, and contribute to atherosclerosis-associated inflammation.

Oxidized LDL

  The oxidized LDL causes specialized immune cells to become foam cells that form the plaques responsible for heart disease. Additionally, exposure of the artery lining to linoleic acid results in increased LDL build-up in arterial plaques, which is considered an essential step in the atherosclerosis process. However, the same researchers found that normal LDL particles did not cause this reaction. 2 If you want more information on which other "numbers" are important on your blood lipid panel (cholesterol test), see my post called Cholesterol: How To Interpret Your Numbers. But for today, I would like to focus on oxidized cholesterol particles, the main reason it becomes oxidized, and how you can avoid oxidized LDL. 

Linoleic Acid

I have written about the health dangers of omega-6 oils before. The predominant omega-6 in our diets is called linoleic acid from canola, corn, soy, sunflower, and safflower oils, etc. They are highly prone to oxidation. Researchers have determined that the more linoleic acid our fat cells have, the more heart disease. 3 Linoleic acids can't be made by our bodies, so it all comes from our diets, and this dietary source gets incorporated into LDL, VLDL, and HDL particles causing them all to oxidize, leading to heart disease. 4 Furthermore, researchers have found that antioxidants like vitamin E have no effect in decreasing their oxidation. 5 Saturated fats do not oxidize, and, surprisingly, may lower your chance of oxidation and heart disease. Despite this information, we were told to substitute linoleic-containing oils like Mazola for the predominantly monounsaturated and saturated fats like butter, lard, and tallow.

Saturated Fat Swindle

Only a few randomized controlled trials have ever tested the traditional diet-heart hypothesis that blames saturated fat for heart disease, yet it remains the gospel truth. The results for two of these trials were not fully reported. Researches recovered unpublished data from the Sydney Diet Heart Study actually showed that replacing saturated fat with vegetable oil rich in linoleic acid significantly increased the risks of death from coronary heart disease and all causes, despite lowering serum cholesterol. Additionally, The Minnesota Coronary Experiment, which is considered one of the most important studies supporting the saturated fat-heart disease connection, also underwent further scrutiny. It was the only randomized controlled trial to complete autopsies of patients with heart disease and the only one to test the clinical effects of increasing linoleic acid in test subjects. According to the new perspective on the data, no evidence for mortality benefit exists from adding linoleic acid, as was stated in the original paper, and the possibility of increased risk of death in older adults is suggested. The latest computations show that participants with a more significant reduction in serum cholesterol from the addition of linolic acid had a higher rather than lower risk of death. 6 More recent research shows that cholesterol was protected from oxidation if bound to saturated fat but susceptible to oxidation when bound to linoleic acid. 7

Hidden Sources of Linoleic Acid

Since the body can't make omega-6 fats/oils, we need to eat some, just not in the enormous amounts found in a typical western diet. Healthy natural quantities are found in nuts and seeds like sunflower seeds, pine nuts, pecans, and Brazil nuts. The linoleic acid content of dairy and meat products varies based on the animals' diets and lifestyles. Milk and cheese also contain linoleic acid. 9

What You Can Do To Lower Your Linoleic Acid Level

The only thing you can do is avoid the processed foods and oils that contain them and get the small amount you need from meat, dairy, nuts, and seeds. If you prefer cooking with oils or adding them to foods, oils like coconut oil, avocado oil, and olive oil are best, but olive oil is most often tainted with seed oils. 10 For cooking use, you can use butter, ghee, and tallow. Also, beware that chicken, beef, and pork fed in feedlots can have higher linoleic acid content. It will take a few years to lower your amount.

Tests For Oxidized LDL and Inflammation

There are several tests available out there that doctors can use to test your inflammation. hsCRP (C-reactive protein) is the most common test that measures for inflammation. It is not specific for where the inflammation is occurring. In addition, oxidized LDL can be directly tested for. Other tests for inflammation linked to heart disease are Lp-PLA2( PLAC® Test) and myeloperoxidase antibody test (MPO). Lastly, Lp(a), also called LP, measures the level of Lp(a) found in a person's blood. Lp(a) looks like LDL, except it has an added protein. Its presence in higher amounts is linked to an increased chance of heart trouble. Unfortunately, it is entirely genetically predetermined, so you can't change it. However, if you have a high amount, let it serve as an extra incentive to lower other risk factors for heart disease.

Conclusion

• Some of the more famous studies we base our beliefs on today misled us with faulty analyses.

• Omega-6 acids are vital for good health but in smaller amounts.

• The predominant omega-6 is linoleic acid.

• Excessive linoleic acid oxidizes and causes health issues, especially heart disease.

• Dietary alternatives to linoleic acid like coconut oil exist.

• You can lower the amount in your body, but it may take a few years.

• If you are concerned about your health, your doctor can order tests to measure your cardiac risk.