If it clears arteries near the heart, it probably keeps other arteries clear too.
Good blood circulation is crucial. Lots of things in your body are crucial, but good circulation *really* is. It probably helps keep your brain working well; a lowfat diet helps preserve people's hearing in old age, I've heard, because of good blood circulation in the ears; prevents strokes, and on and on ...
The supposedly heart-healthy monounsaturated fat, the fat that's in olive oil, may not be so healthy after all. Rudel did some experiments on monkeys that showed monounsaturated fat caused atherosclerosis just as much as saturated fat. Monounsaturated fat is thought to be heart-healthy partly because it doesn't do bad things to blood lipids, as saturated fat does. But Rudel found that it enables the transport of cholesterol from the liver to the heart, causing atherosclerosis. From some experiments on mice, he thinks this mechanism is probably the same for all mammals.
There are hundreds of studies showing the benefits of the omega-3 fats EPA and DHA, though. You only need maybe half a gram or a gram of EPA/DHA per day, so it's easy to still have a low-fat diet. I use EPA/DHA made from algae , because I get sick from fishoil capsules.
You get used to whatever amount of fat you eat. I don't find a very lowfat diet to be depriving at all. I'm not tempted by high-fat foods. When I binge it's on sweets. I gradually cut down on high-fat foods, over months.
The high-carb diet gives me a lot of energy, too.