The seed oat - Avena sativa - was chosen as the medicinal plant of the year 2017
When medicinal plants are mentioned, cereals are certainly not immediately thought of, although they have had their place in medicine for thousands of years. So the oatmeal - Avena sativa - also called white or real oat, even provides several very different remedies with a wide range of uses. They range from skin treatment to gastrointestinal diseases to the prevention of arteriosclerosis and diabetes mellitus type 2. For this reason and because the areas of dermatology and nutrition have not yet been covered by the medicinal plants of the year, the seed oat was chosen as medicinal plant of the year 2017 by the study group Development History of Medicinal Herbology at the University of Würzburg.
Like wheat, rye or barley, oats are sweet grasses (poaceae). In contrast to the relatives mentioned, it does not form its grains in ears, but in multi-branched panicles, which is why an oat plant yields less and is harder to harvest. In addition, the grains are surrounded by husks, which have to be removed by a special milling process. On the other hand, it also thrives on poor soils and in regions with high rainfall. In terms of nutritional value and, last but not least, taste, it is superior to the other cereals.
The oats provide a total of three different remedies. In the relevant specialist literature, only the straw (Stramentum Avenae) is usually found, but more recently the herb (Herba Avenae) and the grain (Fructus Avenae) have become increasingly important.
The oat straw is used for baths, which should help with skin injuries and itching.
To use the herb, the oats are harvested before they bloom. This herb is rich in flavonoids and saponins and has a high proportion of minerals (potassium, calcium, magnesium, etc.), the flavonoids being said to have anti-inflammatory properties and the saponins to have immunomodulating properties. Oatweed extracts are therefore used for dry and atopic skin. The symptoms of atopic skin, also called atopic dermatitis in dermatology, atopic eczema or (obsolete) neurodermatitis, are redness, dandruff, sometimes weeping eczema and severe itching.
In industrialized countries, up to 20 percent of children and three percent of adults suffer from this disease, which is treated externally by combating skin dryness and with anti-inflammatory agents. In the 1990s, a particularly suitable white oat variety was obtained in France, which has a particularly high proportion of flavonoids and saponins. It is harvested very young and cleaned up using a special extraction process. According to the current state of the art, it is free of proteins, including gluten. Its relevance for dermatology has already been shown in recent publications. Appropriate skin care products such as creams, body milk and bath additives are particularly well tolerated for allergy sufferers. In addition to neurodermatitis, oatmeal extracts can also be used to treat wounds and for sensitive skin such as baby skin, aging skin, rosacea and, not least, psoriasis.
Oatmeal extracts are also offered to soothe, relieve stress and improve concentration and learning ability. However, these effects should be underpinned by further studies.
The fruit, the oat grain is used as a fully ripe grain. In addition to a high content of vitamins B1 and B6, oat grain also provides a lot of fiber. Of particular interest are the beta-glucans, which make up about half of the total fiber content in oats. 100 grams of oatmeal contain about 4.5 grams of beta-glucans, in oat bran it is even over 8 grams per 100 grams. The chemical-physical properties of oat beta-glucans have a number of physiological effects on the digestive tract and metabolism. The focus is on positive effects on cholesterol and blood sugar levels.
The ability of the oat beta-glucans to bind bile acids presumably leads to the excretion of cholesterol, which leads to a reduction in the total and LDL cholesterol levels. This can protect the blood vessels from harmful deposits. The European Food Safety Authority (EFSA) therefore confirmed in 2011 that eating beta-glucan from oats can help lower cholesterol levels.
The fiber delays the absorption of the nutrients into the blood. This leads to a less pronounced and delayed rise in blood sugar levels, which leads to a lower release of insulin. For this reason, oat days for patients suffering from type 2 diabetes mellitus were introduced 100 years ago. A recent study at the Diabetologikum in Berlin has shown that insulin administration in patients with a high insulin requirement can be reduced by up to 30 percent after two oat days. The positive effect should be noticeable for up to four weeks.
In addition, the beta-glucans show positive effects on the digestive function. The viscous substance from the soluble fiber protects the intestinal wall from external stimuli and soothes the sensitive stomach. The insoluble fiber regulates digestive activity.
It is not entirely clear whether people with celiac disease can use oat products. In celiac disease, the intestinal mucosa becomes inflamed after eating gluten, so they have to avoid food containing gluten for life. The main components of gluten are prolamin and glutelin. The cause of the disease is the prolamine, the avenin in oat, which is only 15 percent contained in the gluten of oat. This means that the proportion of prolamine in oats is hardly higher than in millet, maize and rice, which are considered to be gluten-free, whereas in wheat, rye and barley it is 34 to 50 percent.
Several studies with celiac patients on oat tolerance have shown that smaller amounts of oats are generally well tolerated. In Sweden and Finland, the consumption of up to 50 grams per day is considered harmless for people with celiac disease, but it must be "non-contaminated oats" that are grown specifically for this purpose and must not be contaminated with cereals containing gluten.
Due to the many possible uses in the field of nutrition and medicine, the seed or white oat was chosen as the medicinal plant of 2017, not without the indication that its potential should still be explored through further research. (Dr. Johannes Gottfried Mayer)