- Febrifuge
- Any substance that reduces unusually high body temperatures (fevers); an antipyretic.
- Fern
- A non-flowering, vascular plant having roots, stems, and fronds.
They reproduce by spores rather than seeds.
- Fixative
- A material which slows down the rate of evaporation of the more volatile components in a perfume composition.
- Fixed Oil
- A name given to vegetable oils obtained from plants, which, unlike essential oils, are fatty, dense, and non-volatile like that found in olive or sweet almond oil.
- Flatulence
- Generating gas in the alimentary canal.
- Flavonoids, or Bioflavonoids
- A large family (over 5,000 so far known) of widely distributed active plant substances, formerly designated as vitamin F.
They are not classified as essential nutrients nor do they have official vitamin status. These compounds consist of multiple ring structures and are often the colour pigments that occur in high concentrations in all fruits, especially citrus fruits, purple berries and apples, as well as in vegetables and whole grains. They are responsible for the astringency of certain fruits and teas.
Research from WWII demonstrated that vitamin C taken with flavonoids (called vitamin F at the time) strengthened capillaries. In the 1950s, flavonoids were frequently prescribed for bleeding. Subsequently, the US FDA ruled that they were ineffective, despite medical experience to the contrary. Flavonoids have been used as supportive treatment for menstrual bleeding, bruising, frostbite, and cold sores. They can also strengthen the blood-brain barrier to increase protection of the nervous system against foreign substances; and they help reduce damage caused by inflammation, thereby reducing allergy symptoms and allowing tissues to normalize.
This is accomplished in the following ways: flavonoids strengthen and repair connective tissue by stimulating the synthesis of collagen, the fibrous protein that holds cells together, and by inhibiting collagen breakdown. Furthermore, these plant materials slow the infiltration of neutrophils, immune cells that can cause damage, into an inflamed area. Flavonoids also stabilize defensive cells in tissues (mast cells), making them less likely to release such substances as histamine, protein-degrading enzymes and leukotrienes that initiate inflammation. Flavonoids can even block the production of proinflammatory prostaglandins and leukotrienes, and act as antioxidants to prevent free radical damage and lipid oxidation that triggers inflammation. Free radicals are highly reactive molecules that tear electrons away from neighboring molecules to make up for their own deficiency.
Studies are showing that flavonoids may decrease the risk of heart attack and stroke. Two properties account for this effect. Flavonoids make platelets less sticky, thus reducing the risk of blood clots. They also act as antioxidants, possibly preventing the oxidation of LDL-cholesterol. Other studies suggest that certain flavonoids block cancers and can activate or inhibit various detoxification enzymes in the liver, thus preventing the activation of carcinogens. The amounts of key flavonoids in foods is still being determined, but it appears that a daily intake of 25-50 mg of key flavonoids offers a degree of protection against heart disease.
How flavonoids are processed in the intestine by gut bacteria, how they are absorbed, and how they are assimilated remain largely unknown. Very likely, combinations of flavonoids together with natural factors found in foods are the key. The long-term effects of using purified flavonoids has not been fully investigated. It should be noted that certain flavonoids can actually increase oxidation, and high levels could inhibit the function of the thyroid gland.
Typical examples of major flavonoids include the following:
- anthocyanins (blue, purple, and red plant pigments) from blueberries, blackberries, raspberries, grapes, eggplant, red cabbage. It has antioxidant properties that also help dilate blood vessels.
- flavones (eg. quercetin) from onions, kale, red cabbage, green beans, tomatoes, lettuce, strawberries, sweet cherries, grapes. It has antioxidant properties and may stimulate detoxification enzymes and strengthen capillaries, blocks inflammation, and may inhibit tumor formation.
- flavanones (eg. naringen, hesperidin, and rutin from citrus).
- flavononols (including catechins, ellagic acid and tannins). Catechin and tannin from green and black tea have antioxidant properties that may also stimulate detoxification exzymes and protect liver, strengthen capillaries, block inflammation, and may inhibit tumor formation. However, these teas also contain drugs that have adverse side effects on the body, so should not be relied on as a prime source of these flavonoids. Ellagic acid from strawberries, grapes, apples, cranberries, blackberries, and walnuts also has antioxidant properties and may help block damage of DNA from carcinogens.
- isoflavones (from soybeans).
- kaempferol from strawberries, leeks, kale, broccoli, radishes, endive, red beets. It has antioxidant properites and may stimulate detoxification enzymes and strengthen capillaries, blocks inflammation, and may inhibit tumor formation.
- Floret
- A small flower; one of individual flowers comprising the head of a composite plant.
- Flux
- The discharge of large quantities of fluid material from a bodily surface or cavity.
- Foliage
- The leaves of a plant or tree.
- Fomentation
- A medicinal compress or poultice that also includes alternating heat with cold.
- Forb
- An herb other than a grass.
- Free Radicals
- Highly reactive molecules that can bind to and destroy cellular compounds.
- Frond
- Foliage of a fern or a palm .
- Fructose
- A yellowish to white, crystalline, water-soluble sugar found in many fruits.
- Fuller’s Earth
- A fine gray powder derived from single-cell algae found on seabeds.
Its absorbent properties and mineral richness make it an excellent face mask.
- Fungicidal
- A substance that prevents and combats fungal infections.
