No, that’s not how it works. Please read the paper I cited. That’s like saying we can breathe water because H2O has O in it. Human bodies are very complex. A strict diet can reduce LDL by around 8-15%. Nowhere near the dramatic decline you indicated. LDL is mostly determined by genetics, with 40-60% heritable. Other causes are related to genetic mutations, excess weight, and metabolic issues like diabetes. Less important factors include menopause, age, hypothyroidism, and certain medications. You likely had a comorbidity. From the paper:

Conclusions: In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol.