which fruits with phytochemicals you should be eating is important. Phytochemicals are chemicals found in plants, and they pack a tangy punch. You might have read about them in some of your favorite magazines or heard about them on television. Most people think that when they hear the word phytochemical, but did you know that fruits like oranges and grapes contain phytochemicals?
List of Phytochemical Foods
When it comes to eating healthy you are probably already aware of the benefits of vitamins and minerals. Scientists have discovered another healthy nutrient in the foods you eat called phytochemicals. Phytochemicals are chemicals produced by plants that have beneficial properties. Plants produce phytochemicals to protect themselves, but when eaten can also protect people. Fruits, vegetables, whole grains, legumes and nuts all contain phytochemicals.
One of the more common phytochemicals is lycopene, belonging to the family of carotenoids. Lycopene is responsible for tomatoes’ red color. Lycopene acts as an antioxidant in your body, protecting you from damage. Lycopene may protect against cancer, especially prostate cancer, heart disease in diabetics, inflammation, infections, arteriosclerosis and toxins. Raw tomatoes are high in lycopene, but the lycopene content increases when they are cooked. Grapefruit, watermelon and red oranges are also good sources of lycopene.
Isothiocyanates, a group of phytochemicals, give cruciferous vegetables their taste. Cruciferous vegetables containing isothiocyanates are broccoli, cauliflower, collards, kale, turnips, cabbage, Brussels sprouts, watercress and cabbage. Isothiocyanates have one of the strongest anti-cancerous properties among phytochemicals. This phytochemical protects you against cancer by neutralizing carcinogens and reducing their detrimental effects.
Fruits, Tea, Wine and Soybeans
Fruits, tea, wine and soybeans all contain phytochemicals from the flavonoids group. Flavonoids are responsible for giving fruit their color. These phytochemicals act as an antioxidant in the body, protecting cells from damage. Other protective health properties linked to flavonoids include allergy reduction, lower risk of cancer, less inflammation and anti-viral properties. The flavonoids found in tea may help lower blood cholesterol level and triglycerides. Soybean flavonoids can lower cholesterol levels as well, but are also used to ease symptoms related to menopause.
Red, Blue and Purple Fruits and Vegetables
The phytochemical anthocyanins give red, blue and purple fruits and vegetables their color. Cherries, acai, blueberries, purple corn, bilberries, blackcurrants and red grapes have the highest content of anthocyanins. While anthocyanins do act as an antioxidant, they are known more for their protection against atherosclerosis, inhibiting tumor growth and their role as an anti-inflammatory.
Phytochemicals in Fruits and Vegetables
Superfood and Functional Food
Fruits and vegetables are the most important sources of phytochemicals. Phytochemicals use for both human diets and natural antimicrobial agents in food preservation. Their benefits for health are mainly due to high antioxidant activity. Antimicrobials of plant origin are known as secondary metabolites that could play a role not only individually or jointly against food‐borne pathogens but also contribute to food flavor. Phytochemicals have a strong effect on control and prevention of natural spoilage processes and growth of microorganisms, including pathogens causing food safety issues. Microorganisms are always associated with harvested plants and slaughtered animals, the basic unprocessed materials of the food industry. Since foods consumed by humans undergo several processing treatments, it is important to understand the effect of such treatments on the phytochemical composition of foods.
- food preservatives
- food spoilage
- food phenolics
Fruits and vegetables are consumed as fresh or processed and known to be among the most important sources of phytochemicals for the human diet. About 200,000 phytochemicals are known so far and 20,000 of them have been identified as originating from fruits, vegetables and grains. Phytochemicals has many health effects as antioxidants against many diseases or antibacterial, antifungal, antiviral, cholesterol‐lowering, antithrombotic, or anti‐inflammatory effects. Phytochemicals are used for various purposes such as pharmaceuticals, agrochemicals, flavors, fragrances, coloring agents, biopesticides and food additives. Their chemical structures composed of phytochemicals such as phenolics, alkaloids, saponins and terpenoids. These compounds are known as secondary metabolites having various identifiable structures, although a benzene ring with one or more hydroxyl groups is a common feature. They are commonly classified as flavonoids (anthocyanins, flavan‐3‐ols, flavonols, proanthocyanidins or flavones, non‐hydrolyzable tannins, isoflavones and flavanones) and non‐flavonoids (hydroxycinnamic, hydroxybenzoic acid, hydrolyzable tannins, benzoic acids and stilbenes). Sugars, acids and polysaccharides are an important source of phytochemicals, secondary metabolites of plants also known as their antioxidant activity and other properties. Lately, there are many investigations on plant “antimicrobial,” “antiviral,” or “antibacterial” effects. In addition, phytochemicals are some of the most important natural preservation structures to reduce and inhibit pathogenic microorganism growth and preserve the overall quality of food products. These antimicrobials can protect food products, extending the shelf life naturally. Chilling, fermentation, freezing, acidification, nutrient restriction, water activity reduction, synthetic antimicrobials and pasteurization have been used in food preservation technology and phytochemicals such as flavonoids, polyphenols, anthocyanins and carotenoids are also used to preserve and control microbial spoilage in foods traditionally. In general, food antimicrobials can be classified as natural and synthetic substances depending on their origin. Synthetic antimicrobials are found in fruits naturally such as benzoic acid in cranberries, tartaric acid in grapes, sorbic acid in rowanberries, malic acid in apples and citric acid in lemons. Secondary metabolites are in close contact through sophisticated communication involving metabolic attacks by plants on their pathogens. Fruits and vegetables have phenolics which are biologically active compounds. Fruits and vegetables have a special phytochemical group which protect plants from their environment stress such as pollution, pathogens, or various abiotic stresses. Even if secondary metabolites having different structures, they can have similar functions. First, plant‐defensive metabolites include phytoalexins biosynthesized to respond to biotic and abiotic stresses with the effect of both protecting the plant and controlling the pathogen growth. Secondly, most of these metabolites are responsible for the organoleptic and qualitative properties of foods originating from such plants. For example, anthocyanins constitute a pigment group responsible for the color of a great variety of fruits, flowers and leaves and flavan‐3‐ols are polyphenols involved in the bitterness and astringency of tea, grapes and wine. Thirdly, these compounds are unique sources of industrial material in the form of food additives, pharmaceuticals and flavors . Finally, they are considered to be beneficial for health, mainly due to their antioxidant activity. Many studies have suggested that a high intake of polyphenol‐rich foods may have cardiovascular benefits and provides some level of cancer chemopreventive activities and beneficial effects against other less prevalent but devastating illnesses, such as urinary bladder dysfunctions and Alzheimer’s disease. Furthermore, food scientists and nutrition specialists suggest that phytochemicals offer many health benefits when consumed as part of the usual human diet.
2. Commonly used methods of treating plant foods
Many fresh fruits especially small berries and vegetables are highly perishable after harvest. During the harvest, bruising can reduce shelf life, influencing both color and texture of fresh products. The freshness of fruits and vegetables can be maintained in storage through reduction of temperature and/or oxygen levels, increase in carbon dioxide levels, use of modified atmosphere packaging or edible coatings, or treatment with gamma irradiation or high pressure. These can also be combined with treatments of 1‐MCP, ozone and ultraviolet (UV) irradiation to further prevent losses. One of the most basic treatments used to lengthen the shelf life of fresh commodities during storage is to store in a low temperature and high relative humidity conditions. It has been known and used to extend the shelf life of fruits and vegetables since antiquity. Moreover, exposure to low temperature during storage optimizes produce appearance and has the additional benefit of protecting nonappearance quality attributes, such as texture, nutrition, aroma and flavor. There are many chemical and natural preservative treatments used to reduce postharvest losses and extend the shelf life of fresh commodities. Using plant extracts with known antimicrobial properties can be of great importance in food preservation. There are some chemical substances in plants that produce a definite action on the microbiological, chemical and sensory quality of foods and these phytochemicals have been grouped in several categories including polyphenols, flavonoids, tannins, alkaloids, terpenoids, isothiocyanates, lectins, polypeptides, or their oxygen‐substituted derivatives. On the other hand, alternative sources of natural products, such as plant extracts, either as pure compounds or as standardized extracts, provide unlimited opportunities for control of microbial growth owing to their chemical diversity. The use of natural antimicrobials as phytochemicals is organic acids, essential oils, or plant extracts and could be a good alternative to ensure food safety. To inactivate or inhibit the growth of spoilage and pathogenic microorganisms during preservation of food, there are several processing techniques used including the use of chemical preservatives and synthetic antimicrobials. However, these techniques have not been considered natural antimicrobial agents in food preservation. But, naturally derived compounds in plant extracts can be good control agents for pathogenic microorganisms. The use of synthetic chemicals is increasingly restricted in many countries. Nowadays, the recent trend has been for the use of natural preservatives due to the adverse health effects of synthetic ones. The alternative methods preserve foods and reduce pest and pathogen injury, with the use of resistant varieties or integrated cropping strategies in which plant secondary metabolites may improve crop protection. The major goals of such natural antimicrobials are to protect the food from food poisoning and spoilage microorganisms that cause off‐odors, off‐flavors and discoloration quality losses. Antimicrobials are called traditional when they have been used for many years and many countries approve them for inclusion in foods. Although many synthetic antimicrobials are found naturally (benzoic acid, sorbic acid, citric acid, malic acid, tartaric acid), the perception of natural has become important for many consumers. The safety and shelf life of food ingredients can also be improved by application of novel technologies to avoid or delay microbial growth like packaging in modified atmosphere, nonthermal treatments, activated films, irradiation, etc. The use of fruits and vegetables as a source of certain phytochemicals, such as ascorbic acid (AA), carotenoids, phenols and flavonoids, has not only health‐promoting effects but also widely used to restrict oxidation‐induced degenerative changes in cell physiology and aging and is well known due to their significant impact on the food industry. Both glucosinolates and leaf surface waxes are important phytochemicals that also play an important role in protecting plants from pest and pathogen injury. These factors that positively affect plant protection also minimize crop damage by pests and pathogens. B‐Carotene, lycopene, lutein and zeaxanthin are known to exhibit antioxidant activity. Increasing oxidative stress results in produce losing keeping quality, not only in terms of microbial contamination, excessive softening and browning but also in terms of significant depletion of phytochemicals, such as phenolics, flavonoids, ascorbic acid and carotenoids. The addition of AA minimizes oxidative deterioration in processed fruits and vegetables. Exogenous treatment of AA in minimally processed fruits and vegetables reduces or stops enzymatic browning and oxidation‐susceptible degenerative changes such as the deterioration of carotenoids, phenolics and flavonoids.
Foods Containing Phytochemicals Phytochemicals are compounds that are produced by plants. Some phytochemicals are believed to protect cells from damage that could lead to cancer. Phytochemicals are compounds that are produced by plants (“phyto” means “plant”). They are found in fruits, vegetables, grains, beans, and other plants. Some of these phytochemicals are believed to protect cells from damage that could lead to cancer. Some scientists think that you could reduce your cancer risk by as much as 40% by eating more vegetables, fruits, and other plant foods that have certain phytochemicals in them. Research has shown that some phytochemicals may: help stop the formation of potential cancer-causing substances (carcinogens) help stop carcinogens from attacking cells help cells stop and wipe out any cancer-like changes Some of the most beneficial phytochemicals are: beta carotene and other carotenoids in fruits and vegetables resveratrol in red wine polyphenols in tea isothiocyanates in cruciferous vegetables (members of the cabbage family that include bok choy, collards, broccoli, brussels sprouts, kohlrabi, kale, mustard greens, turnip greens, and cauliflower) Because these phytochemicals are in the fruits, vegetables, beans, and grains you eat, it’s fairly easy to include them in your diet. A carrot, for example, has more than 100 phytochemicals. Nutrition researchers estimate that more than 4,000 phytochemicals have been identified, but only about 150 have been studied in depth. More research is needed to find out which phytochemicals may offer benefits in reducing the risk of cancer. Keep in mind that there is no evidence that taking phytochemical supplements is as good for you as eating the whole fruits, vegetables, beans, and grains that contain them. Most experts strongly believe that it’s the combination of these compounds and the other foods you eat that keeps your body healthy. Loading up on one or two phytochemicals in pill form probably won’t be as beneficial as eating a balanced diet with a variety of foods that includes 5 or more cups of fruits and vegetables per day and food from other plant sources, such as whole-grain breads, cereals, nuts, seeds, rice and pasta, and beans. There are several main groups of health-promoting phytochemicals. Flavonoids are found in lots of grains, vegetables, and fruits. The flavonoids in soybeans, chickpeas, and licorice may act a little bit like estrogen, a hormone that might affect the risk of breast cancer that depends on estrogen for its growth. The estrogen-like compounds in these plants are called phytoestrogens. But most phytoestrogens have very weak estrogen-like activity. When a weak estrogen-like substance replaces your body’s natural estrogen’s position, then the weak substance can act as a relative anti-estrogen. By acting in this way, phytoestrogens might help work against breast cancer that depends on estrogen for its growth. But phytoestrogens are present in only small amounts in these foods. Learn more about the phytoestrogens in soy foods on the Soy page. Researchers are studying flavonoids to see if they can reduce the risk of certain types of cancers and heart disease. Antioxidants protect your body’s cells from free radicals — unstable molecules created during normal cell functions. Pollution, radiation, cigarette smoke, and herbicides also can create free radicals in your body. Free radicals can damage a cell’s genetic parts and may trigger the cell to grow out of control. These changes may contribute to the development of cancer and other diseases. Antioxidants are found in broccoli, brussels sprouts, cabbage, cauliflower, tomatoes, corn, carrots, mangos, sweet potatoes, soybeans, cantaloupe, oranges, spinach, nuts, lettuce, celery, liver, fish oil, seeds, grains, kale, beets, red peppers, potatoes, blueberries, strawberries, and black and green tea. As a rule, dark-colored fruits and vegetables have more antioxidants than other fruits and vegetables. Carotenoids, which give carrots, yams, cantaloupe, squash, and apricots their orange color, may help reduce the risk of cancer. ADVERTISEMENT Anthocyanins, which give grapes, blueberries, cranberries, and raspberries their dark color, have been shown in the laboratory to have anti-inflammatory and anti-tumor properties. Sulfides, found in garlic and onions, may strengthen the immune system. Much of the evidence so far on the effects of phytochemicals comes from observing people who eat mainly plant-based diets. These people appear to have markedly lower rates of certain types of cancers and heart disease. Some of the associations between specific phytochemicals and cancer risk reduction are very persuasive, but more research is needed. So far there is no conclusive evidence that any phytochemicals will help reduce the risk of getting cancer or help get rid of cancer if you have it. There will never be just one vital food ingredient that you need to include in your diet. Registered dietitians and other healthcare professionals will always recommend eating a balanced diet that includes a variety of vegetables, fruits, legumes, and whole grains.
Phytochemicals’ Role in Good Health
Much of early medicine relied on the prescription of specific plants and herbs for healing, a practice still supported by contemporary research. One of the principle recommendations from the 2010 Dietary Guidelines is to eat more fruits, vegetables, and whole grains by having fruits and vegetables represent one-half of the food on Americans’ plates and making whole grains account for one-half of the recommended six or more daily servings of grains.1 That recommendation was developed based on several population studies suggesting diets rich in fruits, vegetables, and whole grains may offer some degree of protection against cancer, cardiovascular disease, type 2 diabetes, and neurodegeneration.
Consumption of tea, wine, and cocoa, which also are plant based (tea comes from the dried leaves of the Camellia sinensis bush, wine from grapes, and cocoa from the dried and fermented seed of the Theobroma cacao tree), has been associated with reduced risk of these diseases as well.
Naturally occurring compounds, known as phytochemicals (phyto means plant in Greek) are thought to be largely responsible for the protective health benefits of these plant-based foods and beverages, beyond those conferred by their vitamin and mineral contents. These phytochemicals, which are part of a large and varied group of chemical compounds, also are responsible for the color, flavor, and odor of plant foods, such as blueberries’ dark hue, broccoli’s bitter taste, and garlic’s pungent odor. Research strongly suggests that consuming foods rich in phytochemicals provides health benefits, but not enough information exists to make specific recommendations for phytochemical intake.