The term "phyto" originated from a Greek word meaning plant. Phytonutrients, also known as phytochemicals, are organic compounds found in plants that have been shown to protect against disease and improve overall health. Phytonutrients are found in fruits, vegetables, legumes, grains, nuts, and teas, and can even protect against serious diseases such as cancer and heart disease.
The health claims about phytonutrients are not mere speculation. In fact, a recent study conducted by researchers at the University of California, Los Angeles (UCLA) shows that naturally occurring compounds in broccoli and soy may prevent the spread of breast cancer. The research team applied two compounds found in broccoli and soy to live cancer cells and observed that the spread of cancer was significantly reduced. The effect was the same on both prostate cancer and melanoma cancer cells.
"We think these compounds might slow or prevent the metastasis of breast and ovarian cancer, which would greatly increase the effectiveness of current treatments," said Erin Hsu, a graduate student in molecular toxicology at UCLA. The researchers concluded that the levels of phytonutrients needed to have a similar effect in humans would be higher than that provided in a healthy diet, so supplementation might be necessary.
The research is accumulating. The isoflavones in soy products may reduce the risk of heart disease. Phytonutrients in blueberries have been shown to reduce brain aging and maintain healthy vision in rats. Additional research has shown that there is a critical role for fruits and vegetables in reducing your risk of many diseases including cancer, high blood pressure, diabetes, heart disease, and stroke.
There are hundreds of phytonutrients, but the ones we know the most about include carotenoids, coumarins, flavonoids, indoles, lignans, isoflavones, organosulfurs and phytosterols. Carotenoids include yellow, orange, and red pigment in fruits and vegetables. Dark, green, leafy vegetables are rich in the carotenoid known as beta carotene, but the yellow color is masked by chloraphyll, the green pigment in the vegetables. Flavonoids are reddish pigments, found in red grape skins and citrus fruits, and isoflavones can be found in peanuts, lentils, soy, and other legumes. Phytonutrients are part of the plant’s immune system and they protect plants against drought, heat, insects, ultraviolet rays, and pollutants.
Some of the mechanisms by which phytonutrients protect human health include the following:
- They serve as anti-oxidants
- They act as antibacterial and antiviral agents
- They enhance the immune response
- They enhance cell-to-cell communication
- They alter estrogen metabolism
- They kill cancer cells
- They repair DNA damage caused by exposure to toxins
Excellent sources of phytonutrients include: carrots, leafy green and yellow vegetables (eg. broccoli, sweet potato, pumpkin, carrots), peaches, apricots, leafy greens such as kale, spinach, turnip greens, whole grains, tomato products, garlic, pink grapefruit, watermelon, guava, green vegetables, eggs, citrus and berries, and teas.
Soybeans are also considered to be an excellent source of phytonutrients. Not only do they have high levels of protein, they also contain isoflavones and protease inhibitors, which can be beneficial to cardiovascular health. You can also find lots of phytonutrients in legumes such as lentils, peas, and kidney beans.
The National Cancer Institute recommends 5-9 servings of fruit and vegetables per day for optimum health. It is important to note that traditional vitamin supplements do not contain phytonutrients so cannot be used as a substitute for eating lots of fresh fruits and veggies. One of the best ways to ensure you get a good variety of phytonutrients is to be sure you consume lots of different colours of fruits and vegetables. This is because each colour contains different varieties of phytonutrients – the brighter the colour, the more phytonutrients. If you have trouble eating the recommended amounts of fruits and vegetables daily, don’t forget about juicing, which is a great way to get the phytonutrients you need. Phytonutrient supplements are also available, which are made from only the extract of the pigments, which is where the nutrients are especially concentrated in the plant foods.