64 here. Two years ago my LDL was a bit high. And my HDL was low. I did the usual things "diet" and exercise (this is all subjective I know). Was a vegetarian for 30 years who included eggs, fish, and dairy (nothing with legs or wings...). But I was not avoiding processed foods as much as I should. Had some weird heart palpatations that sent me to the ER. Scheduled an angiogram. Found a 30% blockage entering the heart. Not enough to warrant a stent. But enough to scare me. The palpatations it seems were stress related to my job.
So I went total vegan (also decided to retire early)... Started reading about and following
Doctor Esselstyn. Learned how to really cook. Bought an Instant Pot, Nutri-bullet, and started using my food processor. Now I have not been perfect (little or no oil is tough). But as best as I can I've been eating clean (mostly organic) unprocessed non animal home cooked food. After 6 months my numbers were perfect. I also lost about 25lbs.
My cardiologist was impressed. He still doesn't believe it's the reduction of all oils (he's Lebanese so he'd have a tough time). My blood pressure came down too. I'm still at stage 1 hypertension (bad genetics) so I take a pill to keep me in proper range.
Everyone is different. I know the whole Keto thing is raging... But this is what I did. Hope this helps you!
Edit: There's surprising evidence that just 4 Brazil nuts once a month can lower your cholesterol
Here.
I've been doing this as well. BTW, Nutritionfacts.org is a wealth of great information that's been vetted.