Chia seeds come from the chia plant, which is native to central and southern Mexico and Guatemala, and is in the Salvia genus (sage). The chia plant is a flowering plant and is an eremocarp or jointed fruit. The “seeds” have certain properties similar to those of flaxseed, but are only about one millimeter large. They are edible in both raw and dry form, but are usually only available in dried form. We can also dry chia seeds so that they maintain their raw food quality. White and black seeds have about the same nutritional value.
From Wikipedia: “Chia is grown commercially for its seed, a food that is rich in omega-3 fatty acids, since the seeds yield 25–30% extractable oil, including α-linolenic acid. ...
Typically, chia seeds are small ovals with a diameter of approximately 1 mm (0.039 in). They are mottle-colored with brown, gray, black, and white. The seeds are hydrophilic, absorbing up to 12 times their weight in liquid when soaked. While soaking, the seeds develop a mucilaginous coating that gives chia-based beverages a distinctive gel texture.
Chia (or chian or chien) has mostly been identified as Salvia hispanica L. Today, chia is grown and consumed commercially in its native Mexico, as well as in Bolivia, Argentina, Ecuador, Nicaragua, Guatemala, and Australia. New patented varieties of chia have been developed in Kentucky for cultivation in northern latitudes of the United States.”
“A 100-gram serving of chia seeds is a rich source of the B vitamins, thiamine, and niacin (54% and 59%, respectively of the Daily Value (DV), and a good source of the B vitamins riboflavin and folate (14% and 12%, respectively). The same amount of chia seeds is also a rich source of the dietary minerals calcium, iron, magnesium, manganese, phosphorus, and zinc (more than 20% DV).”
“The word "chia" is derived from the Nahuatlword chian, meaning oily. S. hispanica is one of two plants known as chia, the other being Salvia columbariae, commonly known as golden chia.”
Assessment of health benefits and food uses:
“In 2009, the European Union approved chia seeds as a novel food, allowing chia to be 5% of a bread product's total matter. chia seeds may be added to other foods as a topping or put into smoothies, breakfast cereals, energy bars, granola bars, yogurt, tortillas, and bread. They also may be made into a gelatin-like substance or consumed raw. The gel from ground seeds may be used to replace as much as 25% of the egg content and oil in cakes while providing other nutrients.”
“Chia seeds are often categorized as a superfood and advertised as having a wide range of health benefits. Some of this marketing can be attributed to marketing hype.*”
“Although preliminary research indicates potential health benefits from consuming chia seeds, this work remains sparse and inconclusive. In a recent (2015) systematic review, most of the studies did not demonstrate a statistically significant effect of chia seed consumption on cardiovascular risk factors in humans.
No evidence to date indicates consuming chia seeds has adverse effects on or interactions with prescription drugs.”
Note (italics): * = Translation from a German Wikipedia entry