Origin: “Eaten by people in Scotland, but fit only for horses in England,” is how oats are mentioned in Samuel Johnson's dictionary, 
Modern oats apparently originated from the Asian wild red oat which grew as a weed in other grain crops.
Archaeological studies show that oats have been found dating back to 2,000 BC. However, these grains were presumably simply weed seeds. It was perhaps much closer to the birth of Christ before, as the last of the cereals to be cultivated, oats were purposely grown in southeast Europe or Asia Minor. 

Oats were used for medicinal purposes before being used as food.  It was introduced to North America with other grains by Scottish settlers in 1602. They moderately became a major crop until about 1920, when machines began to replace horsepower.  
Greeks and Romans believed oats to be a diseased version of wheat. With the advancement of knowledge about nutrition, oats were acknowledged as a healthy food in the mid-1980s and therefore became more popular once again for human nutrition. 
Oats are primarily considered a secondary crop, obtained from a weed of the primary cereal domesticates. Then, spreading westward into cooler, wetter areas favorable for oats, eventually leading to their cultivation in regions of the Middle East and Europe.

Scientifically: Oats are a whole grain that is often eaten for breakfast like oatmeal. Oats are abundant in carbs and fiber.  In comparison to other grains, they have high levels of protein and fat. They are rich in many vitamins and minerals. 
Oats carry many powerful antioxidants, including avenanthramides. These compounds help in reducing blood pressure and provide other benefits. Oats are rich in the soluble fiber beta-glucan, which has numerous benefits. It helps in decreasing cholesterol and blood sugar levels promote healthy gut bacteria and increase feelings of fullness. 

Oats may lower the risk of cardiovascular diseases by reducing both total and LDL cholesterol and protecting LDL cholesterol from oxidation. Due to the soluble fiber beta-glucan, oats may improve insulin sensitivity and lower the blood sugar levels. 

Oatmeal can also help you lose weight by making you feel fuller as it slows down the emptying of the stomach and increasing the production of the satiety hormone PYY. It helps in keeping skin hydrated by building an occlusive layer that retains water in the skin
Colloidal oatmeal (finely ground oats) has long been used to cure dry and itchy skin. It may help relieve symptoms of various skin conditions, including eczema. It’s non-irritating characterizes ensures that it has low allergenic potential. 

Some research shows that oats may help prevent asthma in children when fed to young infants. Studies suggest that oat bran can help reduce constipation in elderly individuals, significantly reducing the need to use laxatives. 

Oatmeal has high anti-oxidant properties and helps undo the damage done to your skin by pollution, UV ray, and chemicals.  The antipruritic characteristic of oatmeal helps control itching arising from various skin diseases and fungal infections.
Oatmeal has wonderful moisturizing properties. It is rich in proteins and has potent emollient properties. 

Usage: Oats have numerous uses in foods. They are used to make oatmeal, oat flour, oatcakes, oatmeal cookies, oat bread, muesli, and granola. It is also used in various beauty and wellness products. 

Below are some DIYs with oats:

-     Blend 1 tablespoon almond powder, 1 tablespoon oatmeal and 2 tablespoons milk together. Apply this beneficial mixture on your face for 15 minutes. Post that washes it off.  
-     Grind 1 tablespoon of oatmeal and brown sugar into a fine powder. Add half a tablespoon of raw honey, jojoba oil and essential oils.  Your power-packed natural scrub is ready.  
-    Take a tablespoon of oats, one tablespoon of gram flour and a teaspoon of honey. Mix all these ingredients together. Add some rose water to make a paste. Apply this mixture to the face or body and leave it for 15 minutes. Rinse later. This mask helps in smooth and clearer skin.
-    Take two tablespoons of oats and three tablespoons of buttermilk, mix both ingredients together and apply on the skin. Remove the pack with gently massaging the skin and rinse. This helps in removing the tan.
-    Take two tablespoons of oats and a tablespoon of yogurt. Mix them and apply on the face. Leave it on for 15 minutes and then rinse. This mask helps in shrinking of pores and gives healthy skin. 
-    For controlling sebum, take a tablespoon of oatmeal and add some lemon juice to it. Mix and apply this mixture. Rinse after 10 minutes.
-    Take a tablespoon of oats, 1 -2 tablespoons of almonds and half a cup of milk. Mix all ingredients together and apply on the hair. Keep it on for 45 minutes and rinse later. This mask helps in nourishing the hair.