The Chemistry of Cooking Fats: Stability, Inflammation, and Health
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA
In the functional medicine community of Adelaide, “clean eating” is a common focus, yet the foundation of those meals—the cooking fat—is often overlooked. The wrong oil, particularly when heated, can transform an otherwise healthy meal into a source of oxidative stress and inflammation. At Elemental Health and Nutrition, clinical assessment frequently reveals that fat quality plays a meaningful role in gut inflammation and microbiome disruption, especially in patients with chronic inflammatory conditions.
Quick Answer: What Is the Best Oil for Cooking?
The best cooking oils are those with high oxidative stability, not simply a high smoke point. Smoke point describes when an oil begins to burn, whereas oxidative stability reflects how resistant an oil is to heat-induced breakdown into harmful polar compounds. Fats rich in saturated or monounsaturated fatty acids—such as ghee, tallow, and extra virgin olive oil (EVOO)—are among the most heat-stable options for everyday cooking.
The Science: Why Fat Structure Matters
The health effects of cooking fats are best understood by examining their molecular structure, particularly the presence or absence of double bonds.
- Saturated fats (butter, ghee, tallow, coconut oil) contain no double bonds, making them highly resistant to heat and oxidation.
- Monounsaturated fats (olive oil, macadamia oil, avocado oil) contain one double bond and demonstrate good heat stability, especially when accompanied by natural antioxidants.
- Polyunsaturated fats (seed oils such as canola, sunflower, and corn oil) contain multiple double bonds, which are vulnerable sites for oxidative damage during heating.
The Smoke Point Myth vs Oxidative Stability
While smoke point is often promoted as the key indicator of a “safe” cooking oil, research shows that refined oils with high smoke points can generate greater quantities of toxic polar compounds when heated. In contrast, less refined oils such as extra virgin olive oil may remain more stable during typical home cooking due to their antioxidant content.
| Fat / Oil | Oxidative Stability | Primary Use | Clinical Consideration |
|---|---|---|---|
| Ghee (grass-fed) | Very high | High-heat cooking | Heat-stable fat with milk solids removed. |
| Extra virgin olive oil | High | General cooking | Polyphenols help protect against oxidation. |
| Avocado oil | Moderate–high | Higher-heat cooking | Stability depends on being cold-pressed and unrefined. |
| Tallow (beef fat) | Very high | Frying and roasting | Naturally low in polyunsaturated fats. |
| Seed oils (canola, sunflower) | Low | Avoid high heat | Prone to oxidation due to high omega-6 content. |
Why Heated Seed Oils May Contribute to Inflammation
In clinical practice, diets high in repeatedly heated seed oils are commonly observed in individuals presenting with persistent fatigue, immune dysregulation, and metabolic stress. Oxidative by-products formed during heating can impair mitochondrial energy production, a pattern frequently seen in patients with chronic fatigue and post-viral illness.
Excessive dietary omega-6 linoleic acid may also incorporate into cell membranes, increasing susceptibility to inflammatory signaling pathways associated with immune dysregulation.
Sourcing High-Quality Cooking Fats in Adelaide
South Australia produces some of the world’s highest-quality extra virgin olive oils. When selecting cooking fats:
- Check for a listed harvest date to ensure freshness.
- Choose oils packaged in dark glass to reduce light exposure and oxidation.
- Source animal fats from pasture-raised South Australian producers when possible.
Frequently Asked Questions
Can I cook with extra virgin olive oil?
Yes. Despite a moderate smoke point, extra virgin olive oil demonstrates good stability during typical home cooking temperatures due to its antioxidant polyphenols.
Why is ghee often preferred over butter for cooking?
Ghee has the milk solids removed, improving heat stability and making it more suitable for individuals sensitive to lactose or casein.
How can I tell if an oil has gone rancid?
A rancid oil may smell stale, paint-like, or fishy. These odors indicate lipid peroxidation and oxidative degradation.
Key Insights
- Oxidative stability is more important than smoke point when choosing cooking oils.
- Saturated and monounsaturated fats tolerate heat better than polyunsaturated oils.
- Repeated heating of seed oils may contribute to inflammatory burden.
- High-quality extra virgin olive oil is a practical, everyday cooking fat.
Optimise Your Kitchen Pharmacy
The fats used daily play a meaningful role in inflammation, metabolic health, and cognitive clarity. For individuals experiencing chronic fatigue, brain fog, or inflammatory symptoms, reviewing dietary fat intake can be an important step. Personalised nutrition strategies and functional testing can be explored through a consultation at Elemental Health and Nutrition or by reviewing available clinical services via the testing and programs portal.
References
- Guillén MD, Cabo N. Fourier transform infrared spectroscopy in the study of edible oils and fats. Trends in Food Science & Technology. 2002.
- Grootveld M, et al. Health effects of oxidized heated oils. Food Chemistry. 2001.
- Beauchamp GK, et al. Phytochemistry: Ibuprofen-like activity in extra-virgin olive oil. Nature. 2005.
- Givens DI, et al. Current issues in relation to fatty acids in dairy products. Animal. 2006.
- Sharma H, et al. Beneficial effects of ghee: A review. Indian Journal of Medical Research. 2010.
- Wang L, et al. Effect of a moderate-fat diet with and without avocados on lipoprotein particle number. Journal of the American Heart Association. 2015.
- Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomedicine & Pharmacotherapy. 2002.
- Ramsden CE, et al. Use of dietary linoleic acid for secondary prevention of coronary heart disease and death. BMJ. 2013.
- Santos CS, et al. Extra virgin olive oil stability under high temperature. Food Research International. 2013.
- Gertz C. Stability and sensory characteristics of oils during frying. European Journal of Lipid Science and Technology. 2000.
- Spiteller G. The relation of lipid peroxidation processes with atherogenesis. Molecular Nutrition & Food Research. 2005.
- Naviaux RK. Metabolic features of the cell danger response. Mitochondrion. 2014.
- DiNicolantonio JJ, O’Keefe JH. Importance of maintaining a low omega-6/omega-3 ratio for reducing inflammation. Open Heart. 2018.
- Lord RS, Bralley JA. Laboratory Evaluations for Integrative and Functional Medicine. Metametrix Institute; 2008.
- Choe E, Min DB. Mechanisms and factors for edible oil oxidation. Comprehensive Reviews in Food Science and Food Safety. 2006.