You may already have your own reasons why you cut back on red meat a long time ago. Maybe it was because you already knew it wasn’t doing much good in your body. Saturated fat has earned a bad reputation. New research now suggests that may not be the only reason why red meat is linked to heart disease. It seems that bacteria in our intestines convert carnitine, a protein building block that’s plentiful in red meat, into compounds that speed up hardening and thickening of artery walls. The researchers suggest taking extra caution if you take dietary supplements with carnitine.