The #1 MOST Dangerous Fat in the World!

Berg emphasizes that cold-pressed extra virgin olive oil is rich in phytonutrients beneficial for the heart, tissues, and brain. He places it in the top tier of healthy fats alongside cold-pressed avocado oil. Both contain two powerful phytonutrients that reduce inflammation. He warns that refined olive oil has been heated and deodorized, losing these protective compounds and becoming just another source of membrane-damaging aldehydes. Even mayonnaise labeled ‘avocado oil’ typically uses refined oil, never cold-pressed. The message is clear: heating these oils turns a healthy fat into a harmful one.

Berg singles out avocado oil as a healthy fat when cold-pressed, but warns the industry is poorly regulated. He says it’s common to find refined avocado oil mixed with other oils that are hard to detect. He points out that even mayonnaise advertised as ‘avocado oil’ will never say ‘cold-pressed’ on the label, meaning you’re getting the harmful refined version. He advises against heating it, categorizing it as a dressing fat, not a cooking oil. The lutein content gives it an edge for targeted organ protection.

Berg explicitly says cod liver oil is superior to fish oil not just because of omega-3s, but because of the precise DHA:EPA ratio found in cod liver oil. He notes that this ratio is the same as what’s naturally present in the brain, retina, mitochondria, and immune cells, so supplementation with cod liver oil supports those systems more directly. He also points out that cod liver oil keeps additional antioxidants that are lost during fish oil manufacturing, providing a dual benefit of essential fats plus antioxidants that protect them from oxidation inside the body.

Berg lists soy, corn, sunflower, safflower, canola, cottonseed, grapeseed, rice bran, and refined peanut oil as highly problematic. He adds that refined avocado and olive oil, though perceived as healthy, are also heated and become dangerous. He stresses that most people are unaware these oils are already heat-damaged before purchase and are then heated again at home. The result is a massive dietary burden of aldehydes—he says 25% of all calories come from such oils. Fast food frying oil, reused without regulation, is the absolute worst. He also notes that many of these oils are GMO and contain glyphosate residues.

Berg creates a quality hierarchy within saturated animal fats. Conventional lard and tallow are inferior because the animals are fed grains, which shift their fat toward more omega-6 and may directly incorporate seed oils. Pasture-raised and grass-fed versions maintain a more traditional fatty acid profile aligned with what humans evolved eating. He lists conventional lard and tallow as less desirable, then grass-fed tallow and pasture-raised lard as healthier, alongside virgin coconut oil and grass-fed butter. He doesn’t advocate deep frying with them but places them above industrial seed oils.

Berg places coconut oil in his quality scale: refined coconut oil is inferior, while virgin, cold-pressed coconut oil is among the better fats. He includes it in the same tier as grass-fed tallow, pasture-raised lard, and grass-fed butter, all of which are preferable to conventional animal fats or refined plant oils. No extensive additional detail is given, but the message is consistent—unrefined versions protect against aldehyde formation.

This is the final step in Berg’s quality hierarchy for animal fats. He contrasts conventional butter with grass-fed butter as an upgrade. While not delving into deep biochemistry, the recommendation fits the pattern of preferring the natural diet of the animal to avoid alterations that make the fat more inflammatory or less stable.

Berg walks through multiple examples where nutrition advice has been flipped: saturated fats were thought to clog arteries but are now seen as less harmful; cholesterol-containing eggs were considered bad but now improve LDL profiles; whole grains are labeled heart-healthy yet most are refined and turn into sugar, with gluten damaging the gut; red meat was lumped with processed meat and blamed for cancer, yet carnivore diets heal autoimmune and gut-inflammatory diseases; and salt was blamed for hypertension when 90% of high blood pressure cases have an unknown cause not related to salt, likely linked to potassium or vitamin D deficiency. He uses this pattern to argue that unsaturated vegetable oils were wrongly promoted and are in fact a primary driver of heart disease. The inversion is presented as a systemic misdirection that kept the real problem hidden.

Berg explains that polyunsaturated fats have many double bonds that make them highly reactive with oxygen, especially when heated. During industrial refining or repeated frying, these oils form aldehydes. Once consumed, the aldehydes lodge into the lipid membranes surrounding every cell, including the proteins and receptors embedded there. He specifically names the insulin receptor: aldehydes destroy it, causing a direct path to insulin resistance, prediabetes, and diabetes. He notes that 25% of all calories in the modern diet come from these refined oils, making the exposure massive. The oils also make cells stiff and fragile, creating chronic inflammation, and are reused without regulation in restaurants. He emphasizes that the body needs about 600 days to clear these membrane-bound aldehydes, so damage is prolonged.

Berg contrasts fish oil and cod liver oil, both unsaturated polyunsaturated fats with omega-3 fatty acids. He states that the ratio of DHA to EPA in cod liver oil aligns more closely with human brain, retina, mitochondria, and immune tissue than typical fish oil supplements. Additionally, cod liver oil retains more natural antioxidants, giving it further protective benefits. This makes cod liver oil a superior choice for supporting neurological, visual, and immune health. The distinction is not just about omega-3 content but the specific molecular profile that matches the body’s own structures.

Berg points to the carnivore diet trend, where individuals with autoimmune diseases and gut inflammation report dramatic healing. He argues that the original research unfairly grouped fresh red meat with processed meats, creating a false equivalence. The real-world outcomes of elimination diets that center on red meat suggest it is not only safe but can be profoundly restorative. This is another inversion in his list of dietary flips.