Rapeseed oil also known as canola oil has emerged as a potential substance for more expensive olive oil since it has a similar favorable fatty acid content, overall.
In the United States it is one of the most widely used oil for human consumption second only to soybean oil [1].
Canola oil’s consumption has been quite controversial for a few years. There is diffused opinion about its benefits and adverse effects. Some studies have shown that canola oil has the potential to help consumers meet dietary fat recommendations and can be included in a diet designed to regulate their serum cholesterol levels.
Canola Oil
Canola oil is a type of vegetable oil that comes from rapeseed, scientifically known as, Brassica napus , which is a yellow flowering plant that belongs to the cabbage family. The actual name of canola oil is Low Erucic Acid Rapeseed (LEAR).
Due to the high levels of erucic acid, which is a fatty acid, in rapeseed oil it caused various diseases related to heart. But in 1970s rapeseed plant was genetically modified to produce canola oil which has low amounts of erucic acid. It has been recognized as Generally Regarded as Safe by the FDA (Food and Drug administration). Most canola oil that is sold today in the shelves is extracted from genetically modified canola. Also the processing methods used to extract canola oil is complex and involves the use of harmful chemicals.
Tip: Most canola oil sold today is genetically modified.Side Effects of Canola Oil Consumption
Most of the studies so far investigating the relationship between canola oil consumption and health benefits have shown limited evidence of beneficial effects. Although it should be kept in mind only animal studies have been done regarding the toxic effects that it has on living organisms.
Memory Impairment
Canola oil can have harmful impact on one’s memory and their nervous system. A study conducted on mouse models of Alzheimer’s disease showed that canola oil negatively affected their memory as well as the synaptic integrity [2].
Oxidative Stress
Oxidative stress is essentially an imbalance between the production of free radicals and the ability of the body to counteract or detoxify their harmful effects through neutralization by antioxidants.
A research conducted on stroke-prone spontaneously hypertensive rats showed that canola oil can shorten their life spans which was attributed to the oxidative stress that canola oil can impose [3].
Cardiac Issues
Most of the canola oil produced these days is hydrogenated which creates trans fat in the resulting oil. A 0.5g/serving is considered trans free by the FDA. The accumulation of trans fat raises bad cholesterol level (LDL) and put you at the risk of various heart diseases and stroke.
A study on rats with administration of high and low erucic rapeseed oil showed that they formed lesions on the heart [4] [5].
Skin Disorders
Studies conducted show that canola oil is also harmful to the skin, its high consumption can cause cellulite.
Sprague-Dawley rats which were fed rapeseed oil with varying amount of erucic acid developed alopecia and scaly, hemorrhagic, and necrotic tails, as well as scaliness of the feet after 4-5 weeks of treatment [6].
Cerebral Hemorrhage
Oils and fats can induce metabolic syndrome, leading to cardiovascular and cerebrovascular diseases.
A comparative study on stroke-prone spontaneously hypertensive rats using perilla oil and canola oil showed that perilla oil delayed and attenuated cerebral hemorrhage in them in contrast to the aggravating potential of canola oil [7].
Testosterone Level
Canola oil can potentially have adverse effects on the reproductive capacities by affecting the steroid hormones.
Research on stroke-prone spontaneously hypertensive rat showed testosterone lowering activity through the utilization of canola oil [8].
Inflammatory
Vegetable oil such as canola is high in omega 6 fatty acids. They aggravate body’s inflammatory pathways and reduce the availability of anti-inflammatory omega 3 fats in our tissues, resulting in more inflammation. Inflammation of the brain can affect the mental health [9]. Overconsumption of omega 6 fats can increase the risk of development of obesity, irritational bowel syndrome, Type 2 diabetes, asthma etc.
Healthier Oil Substitutes
Much healthier substitutes can be Extra virgin olive oil, cold pressed Coconut oil, cold pressed avocado oil, Grass-fed butter or Ghee. Canola Oil is present in almost every product available in the market because of its cheaper price but nutritionally and physiologically it can be more damaging than being helpful.
Coconut oil can increase good HDL cholesterol level in our body [10], it is beneficial for skin, nervous system and many other organs. It can withstand high heat therefore, being suitable for cooking. Coconut oil, olive oil and avocado oil are all good substitutes for canola oil, all of which are quite beneficial for our health. I use Coconut oil from Viva brand commonly available at Amazon that is organic as well as cold pressed.
Conclusion
It is better if its consumption is limited in day to day life. Although it has been considered GRAS (generally Recognized as Safe) but the studies were not conducted on humans and were limited to animals.
The side effects discussed above effect major organs of the body and risk development of cardiovascular and cerebrovascular diseases, skin disorders, can shorten life overall. Other side-effects which have been reported include respiratory illnesses, loss of vision, constipation, anaemia, heart disease, irritability and low birth weight in infants.
It works well as an industrial oil, not a food, and has been used in candles, soaps, lipsticks, lubricants, inks and biofuels. Keeping various research and studies in view it is better to choose safer oil substitutes for a healthier lifestyle.
References
| [1] | "United States Department of Agriculture," [Online]. Available: https://www.ers.usda.gov/topics/crops/soybeans-oil-crops/canola.aspx#.UVpT8Vdk2PY. |
| [2] | E. Lauretti and D. Praticò, "Effect of canola oil consumption on memory, synapse and neuropathology in the triple transgenic mouse model of Alzheimer’s disease," Scientific Reports, 2017. |
| [3] | P. A. . C. X. . L. L. and . L. P. , "Differential effects of dietary canola and soybean oil intake on oxidative stress in stroke-prone spontaneously hypertensive rats.," Lipids in Health and Disease, 2011. |
| [4] | V. H. . C. R. H. R. and C. D. , "The effects of high and low erucic acid rapeseed oils in diets for rats.," International Journal for Vitamin and Nutrition Research, 1975. |
| [5] | H. H. K. J. and C. A. , "Myocardial lesions in rats fed rapeseed oil. I. Influence of strain of rats.," Canadian Journal of Physiology and Pharmacology, 1977. |
| [6] | H. H. . H. W. K. J. and M. S. , "The development of dermal lesions and alopecia in male rats fed rapeseed oil.," Canadian Journal of Physiology and Pharmacology, 1976. |
| [7] | C. J. . J. J. . K. J. . S. K. . K. K. P. D. . K. T. L. S. A. B. C. E. . L. J. and . K. Y. , "Comparative effects of plant oils on the cerebral hemorrhage in stroke-prone spontaneously hypertensive rats.," Nutritional Neuroscience, 2016. |
| [8] | O. H. . O. N. T. K. F. S. N. T. . Y. K. I. Y. M. D. Y. Y. and . H. S. , "Testosterone-lowering activity of canola and hydrogenated soybean oil in the stroke-prone spontaneously hypertensive rat.," The Journal of Toxicological Sciences, 2010. |
| [9] | R. K. McNamara and F. E. Lotrich, "Elevated immune-inflammatory signaling in mood disorders: a new therapeutic target?," Expert Review of Neurotherapeutics, 2012. |
| [10] | C. D. . M. A. . d. O. G. R. L. R. and . R. G. , "A COCONUT EXTRA VIRGIN OIL-RICH DIET INCREASES HDL CHOLESTEROL AND DECREASES WAIST CIRCUMFERENCE AND BODY MASS IN CORONARY ARTERY DISEASE PATIENTS.," Nutrición Hospitalaria, 2015. |
