Vegetable (Seed) Oils: The Misleading ‘Healthy’ Choice?

The potential negative health effects of high omega-6 industrially produced oils like canola, soy, corn, grape-seed, sunflower and cottonseed:

Gut Health

Gastrointestinal Inflammation: Industrial seed oils, which are high in omega-6 fatty acids, may contribute to gastrointestinal conditions like irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Studies in mice have shown that diets high in omega-6 fatty acids from corn oil increase pro-inflammatory gut bacteria, fostering gastrointestinal pathologies​​.

Altered Gut Microbiota: Human studies indicate a correlation between industrial seed oils and GI conditions. Women with IBS have elevated levels of arachidonic acid (an omega-6 fatty acid) and pro-inflammatory PUFA metabolites compared to healthy controls​​.

Heart and Arterial Effects

Cardiovascular Disease: Oxidised fatty acids from industrial seed oils play a pivotal role in developing cardiovascular diseases. The consumption of linoleic acid-rich oils is linked to the formation of oxidised lipoproteins, which in turn, contribute to atherosclerosis and heart disease​​.

Increased Omega-6-to-Omega-3 Ratio: This imbalance, caused by high consumption of industrial seed oils, is a risk factor for cardiovascular diseases due to the pro-inflammatory and prothrombotic effects of excess omega-6​​.

Brain Effects

Cognitive Decline and Mental Health: A high omega-6-to-omega-3 fatty acid ratio predisposes individuals to depression, anxiety, cognitive decline, and dementia. Canola oil consumption has been linked to worsened memory and impaired learning ability in Alzheimer’s disease​​.

Trans Fatty Acids: Trans fatty acids (TFAs) in industrially produced oils are associated with cognitive decline. They result from hydrogenation and thermal processes like frying and refining of vegetable oils​​.

Metabolic and Mitochondrial Problems

Insulin Resistance and Diabetes: Research indicates that high levels of linoleic acid (the primary fatty acid in industrial seed oils) alter neurotransmitter signalling, increasing food consumption and fat mass. Diets high in soybean oil have been linked to obesity, insulin resistance, diabetes, and fatty liver disease​​.

Obesity: The repeated heating of industrial seed oils depletes vitamin E and induces the formation of free radicals that cause oxidative stress, potentially leading to high blood pressure, heart disease, and liver damage​​.

Other Potential Health Problems

Inflammation: Industrial seed oils raise C-reactive protein, TNF-alpha, and interleukin-6 levels, biomarkers of systemic inflammation​​.

Macular Degeneration: A high intake of omega-6 fatty acids increases the risk of age-related macular degeneration, a leading cause of blindness​​.

Osteoarthritis: There’s an association between omega-6 fatty acids and the presence of synovitis in osteoarthritis. Conversely, omega-3 fatty acid consumption shows an inverse relationship with cartilage loss in the knee​​.

Industrial Processing Concerns

Hexane and Bleach Processing: Hexane, a volatile solvent used in oilseed extraction, is categorised as a hazardous air pollutant by the EPA. Inhalation can damage the nervous system, and ingestion may produce symptoms like abdominal pain, nausea, weakness, and even paralysis​​.

Additives and Free Radicals: Processing of these oils creates free radicals and requires the addition of synthetic antioxidants like BHT, BHA, and TBHQ, which have been linked to cancer, liver and kidney toxicity, and thyroid function depression​​​​.

List of foods and products that typically contain industrially produced oils such as canola, sunflower, soy, grape-seed, corn, cottonseed, and other oils:

- Processed Snacks: Chips, crackers, and microwave popcorn.

- Fast Food: Fried chicken, fries, and other fried items.

- Prepackaged Baked Goods: Cakes, cookies, pastries, and bread.

- Salad Dressings and Mayonnaise: Many commercial varieties.

- Frozen Meals: Ready-to-eat frozen dishes.

- Margarine: Commonly made with these oils.

- Non-Dairy Creamers: Often contain these oils.

- Canned Soups: Some brands use these oils.

- Sauces and Gravies: Pre-made varieties.

- Vegetable Shortening: Often made with these oils.

- Protein Bars or Shakes: Many brands include these oils.

- Chocolate: Some types contain these oils.

- Candy Bars and Candy: Various brands use these oils.

- Oat Milk, Almond Milk, and Other Plant-Based Milks

- Cosmetics and Personal Care Products

- Cooking Oils: Such as corn oil, cottonseed oil, palm kernel oil, safflower oil, soybean oil, sunflower seed oil​​​​.

So why are these oils and fats promoted?

1) Economic Interests: These oils are often derived from crops that are abundantly grown and heavily subsidised in many countries, making them a cost-effective option for manufacturers. Their widespread cultivation and processing became a significant economic driver, incentivizing their promotion and use.

2) Shift from Saturated to Unsaturated Fats: In the mid-20th century, scientific studies began linking saturated fats to heart disease. This led to public health recommendations to reduce saturated fat intake and replace it with unsaturated fats, which are abundant in these oils.

3) Marketing and Lobbying Efforts: The manufacturers of these oils have engaged in substantial marketing and lobbying efforts to promote their products as healthy. This includes funding research that supports the health benefits of their products and marketing campaigns aimed at both consumers and healthcare professionals.

4) Nutritional Misunderstanding and Simplification: Early nutritional science sometimes oversimplified the complexities of dietary fats. The emphasis was often placed on the categorization of fats (saturated vs. unsaturated) rather than the overall quality or processing method of the fat. As a result, all unsaturated fats, including industrially produced oils, were often lumped together as healthier alternatives.

5) Food Industry Influence: The food industry has played a significant role in shaping dietary guidelines and public perception. Industrial oils are versatile and have a longer shelf life, making them attractive to food producers. This economic advantage may have influenced the promotion of these oils over alternatives.

6) Shift in Dietary Patterns: Post World War II, there was a significant shift towards convenience foods in the West. Industrially produced oils were well-suited for mass-produced food items due to their stability, shelf life, and flavor profile.

7) Incomplete or Evolving Science: Nutritional science is continually evolving. Early research that guided dietary recommendations did not always account for the complexities of fat types, their sources, and the impact of processing. As more nuanced research emerges, understanding of what constitutes a healthy oil continues to evolve.

Action points:

1) Pioritise Unprocessed, Natural Fats: Choose fats and oils that undergo minimal processing. This includes extra virgin olive oil, coconut oil, butter, ghee, animal fats like lard and tallow, aa well as fats from avocados, and fatty fish. These natural fats are generally healthier as they undergo less or no processing and retain more of their natural nutrients.

2) Limit Intake of Industrially Processed Vegetable Oils: Reduce consumption of industrially processed oils like soybean, sunflower, canola, corn, and cottonseed oils. These oils often undergo extensive processing and may contribute to inflammation and other health issues.

3) Balance Omega-3 and Omega-6 Fatty Acids: Increase sources of omega-3s (like fatty fish) while reducing foods high in omega-6s (like many processed and fried foods).

4) Avoid Trans Fats: Stay away from trans fats, which are often found in partially hydrogenated oils, used in many processed foods. Trans fats are linked to increased risk of heart disease and other health problems.

5) Cook at Appropriate Temperatures: Use oils that are stable at high temperatures for cooking. For example, olive oil is good for medium-heat cooking, while avocado oil, coconut oil, lard, ghee, and tallow can withstand higher temperatures.

Please look at this well referenced article:

https://chriskresser.com/how-industrial-seed-oils-are-making-us-sick/