en.wikipedia.org/wiki/French_paradox

The article is mixing up two distinct U.S. studies:

1. The 2006 paper it describes is the Women's Health Initiative (WHI) Dietary Modification Trial. The PubMed record for the 2006 JAMA paper is explicitly titled "Low-fat dietary pattern and risk of cardiovascular disease: the Women's Health Initiative Randomized Controlled Dietary Modification Trial" and says it was a randomized trial of 48,835 postmenopausal women with mean follow-up of 8.1 years.

2. The Nurses' Health Study is a different study. A PubMed record describing it is titled "The nurses' health study: a cohort of US women followed since 1976" and lists its affiliation as Brigham and Women's Hospital, not the Women's Health Initiative.

So the article's wording is incorrect because it attributes WHI trial results to the Nurses' Health Study. The sample size (~49,000 women) and follow-up (~8 years) match the WHI Dietary Modification Trial, not the Nurses' Health Study.

This sentence attributes a specific cholesterol mechanism to the Mediterranean-diet trial, but the main trial by de Lorgeril, Renaud, and Salen does not report that the intervention worked by raising HDL and lowering LDL.

In the PubMed abstract for the 1994 Lancet paper "Mediterranean alpha-linolenic acid-rich diet in secondary prevention of coronary heart disease," the authors state that "Serum lipids, blood pressure, and body mass index remained similar in the 2 groups." That directly conflicts with the article's claim that the benefit occurred "through increasing HDL cholesterol whilst reducing LDL cholesterol."

A follow-up paper by de Lorgeril and colleagues in the Journal of the American College of Cardiology also says the exact mechanisms of this protection are unknown and discusses possible roles for omega-3 fatty acids, oleic acid, and antioxidant vitamins. In other words, the researchers did not establish the specific HDL-up / LDL-down mechanism stated here.