You’ve heard of the French Paradox (140K Google hits), the fact that the French have little heart disease in spite of a diet high in saturated fats (the supposedly bad fats). You haven’t heard of the Israeli Paradox (<1K Google hits), which may be more important. (The French Paradox may be an historical accident.) The Israeli Paradox is the fact that Jewish Israelis have very high rates of heart disease, diabetes, and cancer in spite of a diet low in total fat, high in polyunsaturated fats (the supposedly good fats), and low in saturated fats.
The best guess is that the Israeli Paradox is due to a high intake of omega-6 fats (from soybean oil). Non-Jewish Israeli citizens have rates of heart disease, diabetes, and cancer roughly half the Jewish rate. The non-Jews consume lots of olive oil (low in omega-6) rather than soybean oil. This is not an omega-3 effect; olive oil is low in both omega-3s.
“Replacing saturated fats with unsaturated fats [such as omega-6] is a safe, proven, and delicious way to cut the rates of heart disease,” wrote Walter Willett, the Harvard epidemiologist, in Eat, Drink, and Be Healthy (2001, p. 71). The Israeli Paradox shows that this way of reducing heart disease is anything but safe and proven.