When it comes to fats, we often hear conflicting information about what's good and what's not. We've been told to avoid them entirely, embrace them in moderation, or to choose only certain types. These shifting dietary recommendations can be confusing for even the most health-conscious consumers. Let's dive into the world of fats and uncover the truth about the good and the bad.
What are fats & oils, fundamentally?
Fats and oils are types of lipids—organic molecules made up of carbon, hydrogen, and oxygen. Fats are solid at room temperature, while oils are liquid. The fundamental distinction between types of fats lies in their molecular structure.
Saturated Fats: have no double bonds between carbon atoms. These fats are stable at room temperature and are found predominantly in animal products like butter and meat, as well as tropical oils like coconut oil.
Unsaturated Fats: contain one or more double bonds between carbon atoms, which introduce "kinks" in the molecule, making them liquid at room temperature. Unsaturated fats are categorized into two types: Monounsaturated fats (MUFA), found in olive oil, avocados, and certain nuts; Polyunsaturated fats (PUFA), Found in fish, seeds, and some vegetable oils; PUFAs include essential fatty acids like omega-3 and omega-6, which the body cannot produce on its own.
The Evolving View on Dietary Fats
For decades dietary fat was vilified, particularly saturated fats. The assumption was simple: dietary fats raise blood cholesterol levels, which increases the risk of heart disease. We were brainwashed into switching to low-fat foods and products, hydrogenated vegetable spreads instead of butter, and even egg white-only omelettes... What a scam! The biggest nutrition lie in history. Some speculate this originated in the unfortunate mis-interpretation of research conducted in the 70s, which may have benefitted some players in the food industry.
The fact is that this shift didn't make the population any healthier: we cut back on healthy fats, started ingesting manufactured oils that confused our bodies, and replaced the cut-down calories with ultra-processed carbs.
This fad wreck-havocked key body functions that depend on fats. Fats are not only a concentrated source of energy (yielding 9kcal / gram), but they also helps absorb fat-soluble vitamins (A, D, E and K) and minerals such as calcium. Fat is needed to build cell membranes, the vital exterior of each cell in which receptor are found, and the sheaths surrounding nerves; it is essential for blood clotting, hormone and neurotransmitter synthesis, muscles, joints, gut lining, and to control inflammatory pathways.
A diet deprived of healthy fats compromises physical and mental health.
A comprehensive review published in the British Medical Journal in 2020 challenges the old dogma of "low-fat" diets being superior for heart health. What appears to matter more is the type of fat and the broader dietary context.
Monounsaturated fats, such as those found in olive oil, have been consistently linked to heart health benefits, especially when part of a Mediterranean-style diet. Likewise, omega-3 fatty acids, found in fatty fish and certain plant sources, have shown powerful anti-inflammatory properties and may actually reduce the risk of heart disease and cognitive decline.
We all process fats differently and may benefit from more or less fat in our diet. In a similar way, fats are not all the same. So, if saturated fat isn't the enemy, and some unsaturated fats are clearly beneficial, where do we draw the line?
Quality Matters: Cold-Pressed vs. Refined Oils
A critical distinction is how oils are processed. Cold-pressed oils, like extra virgin olive oil, retain more of their natural nutrients and antioxidants because they are extracted mechanically without the use of heat or chemicals. In contrast, refined oils undergo high-temperature processing and chemical treatments, which strip them of beneficial compounds and may lead to the formation of harmful by-products, such as trans fats.
Trans fats, particularly those that are artificially produced through partial hydrogenation, have been consistently linked to negative health outcomes. The World Health Organization has called for a complete elimination of industrial trans fats from the global food supply by 2023, citing their role in increasing the risk of heart disease. However, naturally occurring trans fats, found in small amounts in animal products, do not appear to have the same harmful effects.
The Problem of Ultra-Processed Oils
One of the critical insights emerging from recent research is the distinction between whole-food sources of fatand ultra-processed oils. Highly processed vegetable oils like soybean, corn, and canola oil, which are rich in omega-6 fatty acids, have become ubiquitous in modern diets. While omega-6 is essential in small amounts, its overconsumption—common in industrialized nations—may drive chronic inflammation, a key player in many modern diseases, including heart disease, obesity, and cancer.
A 2021 study in the Journal of Clinical Nutrition suggested that “the modern imbalance between omega-6 and omega-3 fatty acids (with omega-6 dominating) could be linked to the rise in inflammatory conditions”. Historically, human diets contained a balance closer to 1:1, while today's diets can have ratios as high as 20:1 in favour of omega-6. This imbalance could be one of the root causes of many health issues that are often blamed on fats in general.
Key takeaways for those seeking optimal wellbeing
The Path Forward: Personalization and Sustainability
As our understanding of nutrition evolves, so does the realization that there is no "one-size-fits-all" approach to dietary fats. Emerging fields like nutrigenomics suggest that our individual responses to different types of fat are influenced by our genetics. Personalized nutrition plans based on genetic testing may be the future, allowing us to tailor our fat intake to optimize health outcomes.
Additionally, the conversation around fats and oils must now include sustainability. As demand for plant-based oils and animal fats grows, we need to consider the environmental impact of these food sources. For example, the cultivation of palm oil has been linked to deforestation and habitat destruction, while overfishing threatens marine ecosystems.
Fats and oils are no longer the dietary villains they were once portrayed to be. We need to choose wisely, focusing on the quality, balance, and broader context of the fats we consume. The goal is not just to avoid disease but to thrive—nourishing both our bodies whilst looking after our planet and the wonderfully created sources of food we have ben gifted with.
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