Plant compounds that are believed to have health protection qualities
Although it is becoming increasingly clearer, the terms « phytonutrients » and « phytochemicals » are used interchangeably to describe plant compounds that are believed to have health-protective qualities. Among scientists, the term phytochemical is outdated and they now use the term phytonutrient. Phytonutrients refer to the thousands of natural chemicals that food contains. More than 25,000 phytonutrients are found in plant foods. In nature, phytochemicals help protect plants from germs, fungi, insects and other threats. Unlike the vitamins and minerals in plants, phytonutrients are not essential for life. On the other hand, they are wonderful to help prevent diseases and also for the functioning of the body in general.
Phytonutrients are the source of antioxidants. They are found in fruits and vegetables but also in other ingredients such as:
Common classes of phytonutrients include:
- flavonoids (polyphenols), including isoflavones, inositolphosphates, lignans, isothiocyanates, indoles, phenols and cyclic compounds such as saponins, sulphides, thiols and terpenes.
- Ellagic acid
Carotenoids act as antioxidants in our body. There are more than 600. They give fruits and vegetables the colors red, yellow and orange. Carotenoids attack harmful free radicals that damage our tissues, among other things. The types of carotenoids that may have health benefits include Alpha-carotene, beta-carotene, and beta-cryptoxanthin because our bodies can convert all of these elements into vitamin A. Vitamin A helps maintain the proper functioning of our immune system and is necessary for eye health. Yellow and orange foods like pumpkins and carrots, juice in particular, are good sources of alpha- and beta-carotene but sweet potato is superior to them. Squash, beetroot and spinach are also excellent sources of vitamin A. Another carotenoide, lycopene would reduce the risk of prostate diseases. It is particularly found in tomato juice, plain, puree, etc. On the other hand, cooked tomatoes are even more concentrated in lycopene. Lycopene is also present in melon and pink and red grapefruit.
Flavonoids form a subclass of polyphenols and are responsible for the varied color of flowers and fruits. There are more than 6000 to have been described in plants and they represent an important source of antioxidants in our diet. Flavones, flavanones and flavanols are all part of the flavonoids and act primarily as antioxidants by stabilizing peroxide radicals. Flavonoids are found in a variety of plant foods. They are also found in many drinks: red wine, beer, soy milk, tea and dark chocolate. Green tea is a particularly good source of catechins and helps to protect and fight the diseases of certain canceres.
Some scientists prefer to separate, to take into account their particular properties, flavanic derivatives, anthocyanosides and isoflavonoids and retain the name flavonoids in the strict sense for others. Anthocyanins and proanthocyans are particularly concentrated in wild blueberries and cranberries.
- Ellagic acid:
Ellagic acid is a polyphenol found in many fruits and vegetables including: raspberries, strawberries, cranberries, wild blueberries, pecan nuts and pomegranate. Ellagic acid is one of the main constituents of many plants producing tannins known as ellagitanins.
The resveratrol is a polyohenol. Resveratrol is present in some fruits, especially in red grapes and wine. For wine, the importance of resveratrol also depends on the duration of maceration of the skins in the juice. This explains why white wines have less resveratrol than red wines. However, some claim that the antioxidant effect of wine comes from flavonoids and phenol acids rather than from the resveratrol contained in grapes, since the latter is present in doses several hundred times lower. Several studies are underway to properly elucidate the phenomenon. Resveratrol is also found in blackberries (especially cranberries), beans, unroasted peanuts and cocoa in the form of dark chocolate. Rhubarb and granade are also among the plants with a high resveratrol content. Resveratrol is able to inhibit the aggregation of blood platelets.
Glucosinolates are secondary metabolites of plants. They are found especially in cruciferous (cabbage, broccoli, bok choy, etc.). Glucosinolates act as a defense against pests. They are responsible for the bitter or pungent flavor of many common foods like radishes, mustard, and cabbage. The two main classes of phytoestrogenic compounds that have attracted the most attention from researchers are the isoflavones and lignans. We must be careful with glucosinolates because, in high doses in the diet, they become toxic. Consumed below the danger thresholds, their intake develops antifungal, antibacterial, anti-oxidant, antimutagenic and anticarcinogenic properties. Several studies suggest that a diet rich in cruciferous may protect against the risks of lung cancer and colorectal cancer. However, there are conflicting studies.
Their name comes from estrus (fertility period of mammalian females) et.de phyto, plant. The phytoestrogens are a group of compounds produced naturally by plants that have the ability to cause estrogenic effects or anti-estrogenics. The two main classes of phytoestrogenic compounds that have attracted the most attention from researchers are the isoflavones and lignans.
Among food plants, soybeans(Glycine max)and flaxseeds(Linum usitatissimum)are the main sources of phytoestrogens. This is followed by less concentrated berries, pumpkin, whole grains and bran of oats, rye and barley, nuts, cereals, bread, vegetables and fruits. On the non-food side, red clover(Trifolium pratense)is the most studied plant.