While carotenoids are present in most green plants, they only become visible each fall when chlorophyll gets broken down to save energy for the winter.
There are over 1,100 types of carotenoids, pigments which absorb high energy blue and green light, while leaving behind the lower energy red and yellow light.
This is because carrots don't contain Vitamin A but a carotenoid called beta carotene which is a “provitamin” — a substance that can be converted into a vitamin.
Those on short-term organic diets do show higher levels of carotenoids, polyphenols, Vitamin C and E, LDL cholesterol, antioxidant activity, immune system markers, and ever higher semen quality.
那些短期内食用有机食品的人确实体内含有更多的类胡萝、多酚、维生 C E、低密度脂蛋白胆固醇、抗氧化活性、免疫系统标记,以及更高的精液质量。
So, it makes sense that this research from Ohio state found that avocado is a good way to help absorb carotenoids like beta-carotene and convert them to Vitamin A.
The cardinal's bright red comes from carotenoids, the same pigments that make carrots orange, while the black of its face is from melanin, the pigment that colors our hair and skin.