Should consumers heed warnings that linoleic acid (i.e., vegetable oils) induces inflammation and limiting their consumption will make individuals healthier?
A systematic evaluation of 15 clinical trials showed no specific evidence supporting the theory that LA causes inflammation. This study supports current recommendations that a regulated diet of polyunsaturated fatty acids, such as LA, is healthy and acceptable for most Americans (1).
However, some experts noted that the enormous rise in chronic diseases such as obesity, type 2 diabetes, and other inflammatory disorders coincides with omega-6 PUFA-rich vegetable oil intake in the United States (2). The main argument against omega-6 fats is that the body can turn vegetable oils into another fatty acid known as arachidonic acid (3) which is a building block for chemicals that can act in pro-inflammatory ways (4).
Inflammation is the body’s immunological reaction to irritants such as bacteria, germs, foreign objects, exterior injuries, or radiation damage (5). Healthcare professionals usually suggest medication to treat inflammation. However, alternative remedies such as essential oils and cannabidiol (CBD) may also help lessen inflammation.
How Vegetable Oils can be Inflammatory
Chronic diseases, including obesity and inflammation, have slowly increased for over a century. However, these diseases have increased rapidly since the year 2000. Between 2000 and 2010, the percentage of middle-aged persons with several chronic conditions increased by 30%, from 16.1% to 21%. By 2014, it had risen to 32.1 percent in only four years. In the United States today, 40 percent of persons have numerous chronic conditions (6).
Since 1960, consumption of omega-6 polyunsaturated fatty acid (PUFA)-rich vegetable oils has increased. [Text Wrapping Break] These vegetable oils are presently the most extensively used cooking oils in homes and restaurants worldwide. Despite this, there is a scarcity of information about the dangers these oils may pose to human health.
A study indicated that excessive intake of these PUFAs could disturb normal physiological function (7). The researchers defined excessive omega-6 PUFA intake as any amount above 0.4 percent of total dietary energy intake. The study also suggested that lowering omega-6 PUFA-rich vegetable oil consumption while increasing omega-3 PUFA-rich fish oil consumption can prevent various lifestyle disorders.
Omega-6 PUFA-rich vegetable oils correlate with an increase in disorders in general. The study’s authors proposed that the critical factor promoting obesity may be the fatty acid composition itself, not the amount of fat in an individual’s diet.
For example, increased intake of omega-6 PUFAs in the diet increases hunger and adipose tissue inflammation, contributing to obesity (8). While there is no conclusive evidence yet relating vegetable oils and chronic diseases, particularly inflammation, some individuals suggest that trends may give people helpful insights.
For example, more people are quitting smoking, drinking less alcohol, getting more exercise, eating less saturated fat and sodium, and eating more fruits and vegetables in recent years. Despite this, the rates of chronic diseases continue to climb.
All the while, vegetable oil has progressively and quietly crept into kitchens, restaurants, and packaged goods. One article claims that vegetable oils may account for approximately 500 calories per day in most diets or around 20% of everything most people consume (9). The article further suggests that this increase in vegetable oil intake may be one of the primary drivers of chronic diseases.
Which Vegetable Oils Can Cause Inflammation?
While there is still no definitive answer to inflammatory vegetable oils, one study showed the importance of having a proper ratio between the essential fatty acids omega-6 (for example, vegetable oils) and omega-3 (for example, fish oils) (10).
Due to their high omega-6 concentration, consider avoiding the following plant oils:
- Soybean oil
- Corn oil
- Sunflower oil
- Peanut oil
- Sesame oil
- Rice bran oil
Both omega-6 and omega-3 fatty acids are essential fatty acids, which means the body cannot make them, and humans must get them from their food. Some scientists think that a high omega-6 to omega-3 ratio may contribute to persistent inflammation (11) and that high omega-6 fat intake correlates with an increased risk of obesity, heart disease, arthritis, and inflammatory bowel disease (12). However, these connections may not always imply a causal relationship.
Scientists are still learning about the impact of omega-6 fats on the body, and more research is necessary. Some nutritionists suggest keeping a bottle of extra virgin olive oil or avocado oil in the kitchen for regular cooking and flaxseed oil in the refrigerator for cold meals like salads. I Jaimi Jansen, prefer avocado oil for its high smoke point and mild flavor perfect for grilling.
References
- Linoleic Acid, Vegetable Oils & Inflammation. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6179509/
- Are Omega-6 Polyunsaturated Fatty Acid-rich Vegetable Oils Healthy? https://nutrition.org/vegetable-oils/
- No need to avoid healthy omega-6 fats. https://www.health.harvard.edu/newsletter_article/no-need-to-avoid-healthy-omega-6-fats
- Omega-3 Fatty Acids and Inflammatory Processes. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257651/
- What is an inflammation? https://www.ncbi.nlm.nih.gov/books/NBK279298/
- Multiple Chronic Conditions Among Adults Aged 45 and Over: Trends Over the Past 10 Years. https://www.cdc.gov/nchs/products/databriefs/db100.htm
- Intake of ω-6 Polyunsaturated Fatty Acid-Rich Vegetable Oils and Risk of Lifestyle Diseases. https://academic.oup.com/advances/article/11/6/1489/5867525
- Ibid.
- What’s Driving Chronic Disease? https://www.jeffnobbs.com/posts/what-causes-chronic-disease
- The importance of the ratio of omega-6/omega-3 essential fatty acids. https://pubmed.ncbi.nlm.nih.gov/12442909/
- Healthy intakes of n-3 and n-6 fatty acids: estimations considering worldwide diversity. https://pubmed.ncbi.nlm.nih.gov/16841858/
- Health implications of high dietary omega-6 polyunsaturated Fatty acids. https://pubmed.ncbi.nlm.nih.gov/22570770/
- Jaimi Jansen kitchen tips https://www.jaimijansen.com/