Scientists Compared Butter vs Seed Oil Head-to-Head (the results surprised me)

The speaker emphasizes that the negative effects of saturated fat are largely seen in overfeeding studies. He advises that to safely include saturated fats, one should be in a reasonable caloric range and not in a surplus. This is based on the overfeeding study where saturated fat caused a 55% increase in liver fat, largely from fat redistribution.

The speaker notes that the negative effects of saturated fat on liver fat are mitigated if the individual is active and can use the mobilized fat. He suggests that for metabolically healthy, active people, saturated fat can be beneficial.

The speaker argues that the Mediterranean diet, rich in whole food polyunsaturated fats, is healthy. The problem arises when these fats are extracted and oxidized in processed foods. He recommends consuming nuts, seeds, and using olive oil sparingly.

The speaker notes that saturated fat from dairy has significantly better effects than from other sources, likely due to its unique fatty acid composition. He recommends aged cheeses and good cuts of meat.

The speaker warns against simply adding bulletproof coffee or extra butter to a diet without addressing overall dietary quality. He explains that in the context of a poor diet, the additional saturated fat can be harmful.

The speaker presents this study as a counterpoint to the popular anti-seed-oil stance. He explains that in the short term, polyunsaturated fats oxidize faster and can inhibit fatty acid synthesis in the liver, leading to lower liver fat. However, he emphasizes that this is a short-term intervention and that the metabolic health of the individual matters. He also notes that the study used whole food sources of polyunsaturated fats, not oxidized oils. The speaker uses this to argue that we need to look at the whole picture, not live in an echo chamber.

The speaker cites a large systematic review showing that the fatty acid composition of our body fat has changed dramatically, paralleling the obesity epidemic. He notes that this correlation doesn't equal causation, but the review identifies high linoleic acid in subcutaneous fat as a literal risk factor for coronary artery disease. This suggests that long-term accumulation of linoleic acid from seed oils could be harmful, even if short-term metabolic markers improve.

The speaker explains that when linoleic acid within LDL is oxidized, it forms aldehydes and ketones that bind to ApoB, altering the LDL particle so it can no longer dock with its normal receptor in the liver. Instead, it is taken up by scavenger receptors, initiating the atherosclerotic process. This mechanism underscores why the oxidation state of polyunsaturated fats matters more than just the type of fat.

The speaker breaks down the study to show that saturated fat overfeeding led to increased lipolysis, mobilizing fat from adipose tissue and redepositing it in the liver. Only 26% of the liver fat came from new fat formation, compared to 98% for sugar. This suggests that saturated fat in excess can be particularly harmful for liver health by redistributing existing fat to the liver, while sugar creates new fat. However, he notes that this was in an overfed state, and for active individuals who can oxidize the mobilized fat, saturated fat may not be problematic.