Dave Asprey seems to do a good job at explaining what this study means:

“Something truly epic happened today that is going to change what you eat for years to come. Truly epic. The Journal of the American College of cardiology published a groundbreaking paper today admitting something that you already knew if you had been on the Bulletproof Diet for the last 10 years. (Yes, I am feeling slightly vindicated after receiving so much resistance after writing The Bulletproof Diet, which eventually helped people lose about 1,000,000 pounds!)This new paper, which uses data from studying 135,000 people overtime, finds:-Saturated fat from meat and dairy do not cause an increase in cardiovascular disease, and reduce stroke risk.-Polyunsaturated fats increase risk of cardiovascular disease.-Different fats do different things-Cutting saturated fat does not reduce death rate-the 25% of people eating the highest saturated fat intake (about ∼14% of calories) had lower risk of stroke-Only 5% of fat should be polyunsaturated for lowest death. This is effectively a deathblow to vegan and plant-based practices, which make people sick over time because they contain almost all polyunsaturated fats. It’s one reason I got sicker when I was a vegan. (It takes 2 years to replace half your cell membrane fats when you change your diet.)”