This is a Work in Progress
| Change History | |
| 2023-02-02 | First published |
In 2022, there was a growing viewpoint being echoed on social media about the health implications of rapeseed oils, such as canola oil - that these oils were especially bad to use. The controversy continues, but it still remaind somewhat unclear. Both sides of the argument present convincing points.
After listening to a recent podcast providing detailed reasons why canola and other rapeseed oils are harmful, I decided to look further into it, myself... What do the studies say? What are the components of seed oils that make them harmful and, in reality, despite possible harmful chemicals or chemical byproducts, is there evidence that consuming seed oils is actually harmful?
It turns out that it isn't so simple...
Seed oils, such as soybean, canola, cottonseed, and corn oil, have been criticized for being high in Omega-6 fatty acids and low in Omega-3 fatty acids. An imbalance of these essential fatty acids has been linked to various health issues, including inflammation, cardiovascular disease, and increased risk of certain types of cancer. Additionally, seed oils are often highly processed and may contain harmful substances such as trans fats, solvent residues, and oxidative by-products. It is suggested that there may be healthier options like olive oil, avocado oil, or coconut oil, however the verdict may not be that simple. Other studies have shown that canola oil may actually be beneficial to lowering cardiac risk.
For now, this page will only be a reference to other articles, podcasts and other literature that provides a view on this subject. I won't attempt to provide my own viewpoint on this, but simply present what seems to be verifiable facts to help people make informed decisions on this.
Word List
| Atherogenicity | The formation of abnormal fatty or lipid masses in arterial walls |
| Oleate or Oletic Acid | Oleic acid is classified as a monounsaturated omega-9 fatty acid |
| Linoeate or Linoleic Acid | A polyunsaturated fatty acid, found in plant oils. Omega-6 series fatty acids, essential for human nutrition - cannot be synthesized by the body. |
| Monounsaturated | Fat molecules that have one unsaturated carbon bond in the molecule. Oils that contain monounsaturated fats are typically liquid at room temperature but start to turn solid when chilled. Found in animal flesh such as red meat, whole milk products, nuts, and high fat fruits such as olives and avocados. |
| Polyunsaturated | Polyunsaturated fats are a type of healthy fat that includes omega-3 and omega-6 fatty acids, which are essential for brain function. You must obtain them from food, as your body cannot make them. Sources include fish and plant based oils. |
| Oxidation of LDL | Oxidation in low-density lipoprotein (LDL) refers to a process where molecules called free radicals damage the LDL particles. This can cause the LDL particles to become more harmful and contribute to the development of heart disease. Oxidation of LDL can lead to the formation of conjugated dienes, lipid peroxides, and modification of LDL protein, which makes the LDL more susceptible to degradation by cells in the body, such as macrophages and endothelial cells. The process of LDL oxidation is considered a key factor in the development of atherosclerosis, or the buildup of plaque in the arteries, which can lead to heart disease. |
Journal Articles
📰 (1993) Effects of oleate-rich and linoleate-rich diets on the susceptibility of low density lipoprotein to oxidative modification in mildly hypercholesterolemic subjects. P Reaven, S Parthasarathy, B J Grasse, E Miller, D Steinberg, and J L Witztum
- This study looked at the effects of feeding two different diets to people with slightly high cholesterol levels.
- One diet was oleate-rich (high in monounsaturated fats) and the other was linoleate-rich (high in polyunsaturated fats).
- The researchers found that the people who ate the oleate-rich diet had less prone to harmful oxidation in their low-density lipoprotein (LDL) and high-density lipoprotein (HDL) compared to those who ate the linoleate-rich diet.
- The study shows that changing the type of fat in your diet can affect the fatty acid composition in your LDL and HDL and can affect the likelihood of LDL oxidation, which is linked to heart disease.
- The researchers suggest that eating monounsaturated fats instead of saturated or polyunsaturated fats might be better for preventing heart disease.
- This article reports the results of a study that compared the effects of two diets on patients who had previously had a heart attack.
- The study was conducted over a 5-year period and followed 302 patients who were randomly assigned to a Mediterranean diet that was rich in alpha-linolenic acid and 303 patients who followed the usual post-heart attack diet.
- The results showed that patients who followed the Mediterranean diet consumed less unhealthy fats and had higher levels of certain vitamins and minerals, compared to the control group.
- After a 27-month follow-up, the patients in the Mediterranean diet group had fewer cardiac deaths and non-fatal heart attacks, as well as lower overall mortality, compared to the control group.
- The study suggests that the Mediterranean diet may be more effective than the usual post-heart attack diet in preventing future heart problems and deaths.
- This research studied the effects of different diets on oxidized low-density lipoprotein (LDL), which is a type of cholesterol linked to an increased risk of heart disease.
- The study involved 37 healthy women who were fed two diets, both of which contained less total and saturated fat compared to their regular diets.
- One diet was low in vegetables, while the other was high in vegetables, berries, and fruit.
- The study found that both the diet low in vegetables and the diet high in fruits resulted in an increase in the amount of oxidized LDL and lipoprotein(a) in the blood of the participants.
- This study looked at the impact of different levels of polyunsaturated fatty acids (PUFAs) in the diet on markers of oxidative stress in 10 healthy male volunteers.
- The volunteers followed two diets: one with 5% PUFAs and another with 15% PUFAs, each for 4 weeks with a 6-week break in between.
- The study found that when the volunteers consumed the diet with 15% PUFAs, there was an increase in a marker of oxidative stress (oxidized glutathione) in the blood.
- The study also found that a marker of lipid peroxidation (urinary TBARS) increased after the high PUFA diet and decreased after the low PUFA diet.
- However, other markers of lipid peroxidation and red cell antioxidant enzymes remained unchanged.
- The study also found that total cholesterol increased after the low PUFA diet.
- The results suggest that while increasing PUFAs in the diet may have benefits for cholesterol levels, it may also increase oxidative stress, so it's important to balance PUFA intake with adequate antioxidant intake.
