Recent studies have provided clearer answers on what drives elevated blood cholesterol levels. The long-standing warnings about eggs and dietary cholesterol have largely been overstated. Instead, saturated fat is the primary culprit behind rises in artery-clogging LDL cholesterol.
For decades, eggs were viewed as risky due to their cholesterol content. However, rigorous clinical trials now show that dietary cholesterol has minimal impact on blood LDL levels for most people. The liver tightly regulates its own cholesterol production and compensates for intake from food. In contrast, saturated fats, found in red meat, butter, full-fat dairy, and many processed foods, strongly raise LDL cholesterol. Replacing them with soluble fiber (such as oats and beans) and polyunsaturated fats (from nuts, seeds, and fatty fish) helps the liver remove excess LDL more effectively.
A notable 2025 randomized crossover trial demonstrated this clearly: consuming two eggs per day as part of a low-saturated-fat diet actually lowered LDL cholesterol compared to a high-saturated-fat diet with minimal eggs. Across diets, saturated fat intake correlated strongly with higher LDL, while dietary cholesterol did not.
The picture becomes more nuanced with low-carbohydrate diets. While keto-style eating often leads to weight loss, it can paradoxically increase cholesterol levels in some individuals, particularly leaner people. Researchers link this effect to shifts in the gut microbiome, including reduced levels of beneficial Bifidobacteria that help metabolize cholesterol.
These findings highlight the importance of personalized nutrition. Most people can safely enjoy eggs as part of a balanced diet focused on minimizing saturated fat and maximizing fiber and unsaturated fats. Managing cardiovascular health requires looking beyond single nutrients and considering overall dietary patterns.
[Carter, S., et al. (2025). Impact of dietary cholesterol from eggs and saturated fat on LDL cholesterol concentrations. The American Journal of Clinical Nutrition. DOI: 10.1016/j.ajcnut.2025.02.001]
Your ability to burn fat is not determined by willpower.
The limiting factor is your mitochondria. The study found that individuals with greater mitochondrial abundance achieved significantly higher peak fat oxidation, independent of aerobic fitness. Fat metabolism is not a motivation problem. It is a cellular infrastructure problem.
The biology of performance begins long before the workout starts.
Vertebrate animals cannot convert ฮฉ-6 polyunsaturated fatty acids (PUFAs) to ฮฉ-3 or vice versa, so dietary PUFA intake determines tissue ฮฉ-6:ฮฉ-3 levels.
Some creatures have enzymes that can interconvert ฮฉ-6s and ฮฉ-3s, allowing them to maintain an even balance even when dietary intake ratios are skewed.
What happens when genetically engineer mice so they have that gene, called "fat-1"?
With the fat-1 gene, mice can now convert excess dietary ฮฉ-6 PUFAs into ฮฉ-3s, maintaining a more even balance.
Engineered mice have these features:
- Resistant to obesity, diabetes & liver disease
- Increased energy expenditure
- Lower inflammation
Look at the pictures below. Normal mice ("wt") gain much more weight on a high-fat diet than "fat-1" mice, which convert excess ฮฉ-6 PUFAs into ฮฉ-3s.
Source in reply.
Cancer was, in the 1920s, named the disease of the modern industrial age.
Otto Warburg, working in Berlin, demonstrated that cancer cells run on glucose. They prefer it. They run on it inefficiently, even in the presence of oxygen, in a way healthy cells do not. He won the Nobel Prize in 1931 for the work. The mechanism is now called the Warburg effect and sits in every oncology textbook published since.
In the 1970s, an American radiologist used Warburg's principle to build the PET scan. He injected radioactive glucose into the patient, waited twenty minutes, and watched on the screen where the glucose concentrated. The tumour lit up. The healthy tissue did not.
The machine has been used millions of times. It is, mechanically, a sugar detector. The thing it is detecting is the thing the cancer is eating.
The patient, after the scan, walks down the corridor to the oncology consultation. The oncologist explains the diagnosis. The dietitian, often in the same building, recommends wholegrain pasta, oat porridge, and fruit at every meal as part of a balanced recovery diet.
The mechanism is in the textbook. The textbook is on the shelf. The shelf is in the same building as the dietitian.
The two have not been introduced.