This is from the first hit on google when searching for 'cilantro health benefits':
Health benefits of cilantro (coriander)
Cilantro herb contains no cholesterol; but is rich in anti-oxidants and dietary fiber which help reduce LDL or "bad cholesterol" while increasing HDL or "good cholesterol" levels.
The leaves and seeds contain many essential volatile oils such as borneol, linalool, cineole, cymene, terpineol, dipentene, phellandrene, pinene and terpinolene.
The leaves and stem tips are also rich in numerous anti-oxidant polyphenolic flavonoids such as quercetin, kaempferol, rhamnetin and epigenin.
The herb is a good source of minerals like potassium, calcium, manganese, iron, and magnesium. Potassium in an important component of cell and body fluids that helps control heart rate and blood pressure. Iron is essential for red blood cell production. Manganese is used by the body as a co-factor for the antioxidant enzyme superoxide dismutase.
It is also rich in many vital vitamins including folic-acid, riboflavin, niacin, vitamin-A, beta carotene, vitamin-C that are essential for optimum health. Vitamin-C is a powerful natural antioxidant. Cilantro leaves provides 30% of daily recommended levels of vitamin-C.
It provides 6748 IU of vitamin-A per 100 g, about 225% of recommended daily intake. Vitamin-A, an important fat soluble vitamin and anti-oxidant, is also required for maintaining healthy mucus membranes and skin and is also essential for vision. Consumption of natural foods rich in vitamin-A and flavonoids (carotenes) helps body protect from lung and oral cavity cancers.
Cilantro is one of the richest herbal sources for vitamin K; provides about 258% of DRI. Vitamin-K has potential role in bone mass building by promoting osteotrophic activity in the bones. It also has established role in the treatment of Alzheimer's disease patients by limiting neuronal damage in their brain.
The coriander seeds oil have found application in many traditional medicines as analgesic, aphrodisiac, anti-spasmodic, deodorant, digestive, carminative, fungicidal, lipolytic (weight loss), stimulant and stomachic.
Just imagine! Cilantro leaves provides only 39 cal/100 g, but their phyto-nutrients profile is no less than any high calorie food source; be it nuts, pulses or cereals or meat group.
This humble backyard herb provides (% of RDA/100g)-
15% of folates,
11% of vitamin B-6 (pyridoxine),
45% of vitamin C,
225% of vitamin A,
258% of vitamin K,
22% of iron and
18% of manganese.
(Note: RDA-Recommended daily allowance)
Similar high praise can be found for cinnamon, ginger, and just about any other herb or spice that can be found in the herb or spice aisle at the supermarket. Certainly, food preferences can be used to emphasize in-group/out-group divides, but the simplest hypothesis for their presence in our diets at all is that they were found (probably accidentally) to have benefits. You have to know they exist and at least won't kill you before you start using them for all these downstream reasons, like making other foods hyper-palatable or flaunting tribal differences.