Jeff, I know your general position on "the latest study," but this one seems to merit attention.
Published in Annals of Internal Medicine, it involves "Nine systematic reviews and 4 new RCTs were selected that encompassed a total of 277 trials, 24 interventions, and 992 129 participants." And no apparent funding conflicts.
They found that supplements don't seem to help with cardiovascular health or mortality. That supports the general Dr. McD. message.
But they also found that low-fat diets "had no significant effect" on either mortality or cardiovascular disease outcomes.
Thoughts?
Study link: https://annals.org/aim/article-abstract/2737825/effects-nutritional-supplements-dietary-interventions-cardiovascular-outcomes-umbrella-review-evidence
NY Times article about: https://www.nytimes.com/2019/07/08/well/eat/supplements-and-diets-for-heart-health-show-limited-proof-of-benefit.html