Epidemiological studies can control for things that aren't being controlled for, or just have bad data.
Israelis have relatively high rates of heart disease despite eating one of the most PUFA-rich diets in the world. This has resulted in the coining of the "Israel Paradox."
Israel might not singularly disprove what you posted, as I don't have high insight into Israeli lifestyle habits. It's just food for thought.
" In fact, Israeli Jews may be regarded as a population-based dietary experiment of the effect of a high omega-6 PUFA diet, a diet that until recently was widely recommended. Despite such national habits, there is paradoxically a high prevalence of cardiovascular diseases, hypertension, non-insulin-dependent diabetes mellitus and obesity-all diseases that are associated with hyperinsulinemia (HI) and insulin resistance (IR), and grouped together as the insulin resistance syndrome or syndrome X. "