From the sultry red of an apple to the vibrant green of broccoli and the yellow of split peas, the plant world offers a stunning array of colorful — and delicious — delights. But did you ever wonder where these colors come from and why eating a variety of them is important?
Let’s dive into the “secret” behind plant colors — phytochemicals. Of course, putting down a plate of colorful plants is not your dog’s complete diet (discuss that with your veterinarian or dog nutritionist), but feeding your dog “all the colors of the rainbow” does promote health and longevity.
What they are
Phytochemicals are natural chemical pigments produced by plants (“phyto” means plant). They are biologically active compounds that serve a purpose, such as protecting plants from insect predation, pathogens and diseases. They also contribute to the plant’s color, flavor and odor.
Researchers are discovering that phytochemicals also provide important health benefits. It’s estimated that there are more than 5,000 phytochemicals. Scientists are just beginning to uncover their disease-fighting properties:
✤ Benefiting heart health
✤ Boosting the immune system
✤ Fighting inflammation
✤ Increasing longevity
✤ Lowering cholesterol and blood pressure
✤ Promoting healthy vision
✤ Protecting against cancer
Behind the colors
Plant foods fall into five color categories based on their phytochemical content:
Red, Orange/Yellow, Green, Blue/Purple, Brown/White
Let’s take a closer look:
Red: Red-pigmented plant foods are rich in lycopene and anthocyanins. Lycopene, an antioxidant in the carotenoid family, benefits heart health and helps fight certain types of cancers, including prostate cancer. Anthocyanins, a group of compounds in the flavonoid family, help prevent heart disease and diabetes, improve eye health, decrease obesity, halt the growth of cancerous cells and protect cells in the nervous system from oxidative damage and neurotoxicity.
Orange/Yellow: Orange and yellow fruits and vegetables boast high levels of alpha-carotene, beta-carotene and beta-cryptoxanthin, phytochemicals in the carotenoid family. These compounds are referred to as “pro-vitamin A,” because dogs, like people, canconvert them into pre-formed vitamin A (Retinol). Vitamin A is an antioxidant with important benefits, including supporting healthy eyes, skin and bones, boosting the immune system and promoting optimal reproductive health. Lutein and zeaxanthin are plentiful in the retina. Studies show higher intake of these phytochemicals reduces the risk of age-related macular degeneration.
Green: Green fruits and vegetables are powerful anti-cancer foods packed with disease-fighting phytochemicals, including carotenoids, isothiocyanates and indoles. Their dominant green pigment comes from chlorophyll, one of the most important compounds on Earth. Plants use chlorophyll to capture and convert sunlight into the energy they need to grow. This process, called photosynthesis, results in the release of oxygen into the air, which is necessary for humans to sustain life. Animal studies have shown that chlorophyll may slow and prevent the growth of cancer.
Blue/Purple: Like their red cousins, blue and purple plant foods get their pigments from anthocyanins. Anthocyanins possess powerful antioxidant activity, and their ability to scavenge free radicals enables them to play an important part in blocking a number of disease pathways. Anthocyanin pigments appear redder in acidic conditions and bluer in alkaline conditions.
Brown/White: White fruits and vegetables are rich in anthoxanthin, a flavonoid pigment that may help promote cardiovascular health, decrease inflammation and protect against cancer. Allicin in white foods such as garlic possesses powerful antimicrobial effects and has been shown to inhibit certain bacteria, viruses and yeasts. Sulforaphane, a phytochemical abundant in cruciferous vegetables such as cauliflower and cabbage, contains potent anti-cancer properties. Polyphenols and flavonoids in button mushrooms act as powerful antioxidants studied for their heart health and anti-cancer properties.
And, let’s not forget proteins. Lentils are a great protein source, especially those that are red or yellow, as they cook up nice and mushy for dogs. Also, split peas, peas and all beans (such as black beans and red kidney beans) are good pigmented plant protein sources.
When considering phytochemicals, opt for whole foods rather than supplements. Nature provides the perfect synergy of compounds for optimum nutrient delivery and absorption.