What are phytonutrients? Phytonutrients, aka phytochemicals, are the compounds in plants that protect them from harm, either from insect invasion or from UV radiation damage. For the human beings who eat these whole plant foods, they also provide protection, namely in anti-inflammatory and antioxidant activity.
Where can you find phytonutrients? Well, whole grains, colorful fruits and veggies, and certain spices are all examples of phytonutrient-rich foods, and the benefits of phytonutrients on human health can be significant. From help repairing DNA damage, to immunity enhancement, to carcinogen detoxification, and, according to the U.S. Department of Agriculture (USDA), eating a diet high in phytonutrients is an effective way to reduce your risk of heart disease and cancer. For more facts about phytonutrients and where to find them, read on.
What Are Phytonutrients?
Phytonutrients are often the chemicals that give plants their colorful pigments, so a quick way to guess accurately which foods are rich in phytochemicals is to pick plants with deep hues. Darker greens, bright melons, ink-dark berries, and vibrant spices. These plants are often as rich in color as they are in aroma and flavor, so certain non-colorful foods like garlic or onions are strong in phytonutrients too. For a general list, phytonutrients are the protective chemicals in plant foods like:
Though there are thousands of these compounds in many natural whole foods, the most common phytonutrient chemicals you’re likely to run across are:
- Carotenoids: Important for immune and eye health, carotenoids like zeaxanthin and lutein can help reduce the risk of macular degeneration by 43%.
- Ellagic acid: This polyphenol (micronutrient) is an antioxidant that helps remove toxins from the body and protects against free radical damage. This acid has also shown some ability to inhibit cancer cell growth.
- Flavonoids: These chemicals help guard against cardiovascular disease, are anti-inflammatory, anti-cancer, and can stimulate detoxification processes.
- Glucosinolates: This phytonutrient is another anti-cancer compound found most often in cruciferous vegetables and helps eliminate toxins from the body.
- Phytoestrogens: These plant nutrients are most often found in grain and soy products, and are linked to a reduced risk of breast cancer, especially when eaten regularly during childhood development.
- Resveratrol: Found in the skin of red grapes, resveratrol is thought to work as an antioxidant in the fight against heart diseases and cancers.
Phytonutrient Facts and Food Sources
Here are the specifics behind each of the above-mentioned phytochemicals along with lists of phytonutrients foods for each one.
There are over 600 distinct carotenoids behind many of the orange, red, and yellow pigments found in plants, of which carrots are the most famous. The most common carotenoids in the Western diet are beta-carotene, beta-cryptoxanthin, alpha-carotene, lutein, lycopene, and zeaxanthin, each with their own unique set of powers.
Carotenoids are most closely linked with health benefits like immune system performance, eye health, antioxidant activity, cell signaling, and the reduced risk of cancer and cardiovascular disease. Alpha- and beta-carotene along with beta-cryptoxanthin can be converted into vitamin A in the body (retinol), which is important for immune function and to help prevent premature aging. Zeaxanthin and lutein assist the eyes in preventing macular degeneration.
The brightest fruits and veggies are so vibrant because of their carotenoid content, including the following plant foods:
- Bell peppers
- Sweet potatoes
It’s recommended that you eat carotenoid foods along with a dietary fat to maximize their absorption in the body.
Ellagic acid is also frequently referred to as a tannin, and can be found in dark berries and nuts. This phytochemical is also produced when the body breaks down bigger phytonutrients known as ellagitannins.
Ellagic acid is highly absorbable and scientifically linked to reducing arterial plaque, lowering blood pressure, and exhibiting anti-cancer and anti-inflammatory activities. Ellagic acid may also aid in the liver’s detoxification work, possibly by removing carcinogens before the liver can metabolize them.
A 2010 study showed that ellagic acid helped improve glucose metabolism by blocking the enzyme alpha-glucosidase in the intestines, which is the catalyst that triggers the absorption of glucose. With less glucose reaching the bloodstream, ellagic acid could help those with hyperglycemia or type 2 diabetes manage their conditions.
Ellagic acid’s antioxidant and anti-inflammatory properties can be gained from the following foods:
One of the larger groupings of phytochemicals, flavonoids include the compounds kaempferol and quercetin, and a multitude of subgroups like anthocyanins, flavonols, flavones, isoflavones flavonones, and flavanols (try to say that three times fast!). A massive 25-year study published in 1995 found that flavonoids were significantly associated with improved longevity in men across 7 different countries.
With so many distinct groups, flavonoids span a wide array of foods, including:
- Green tea
- Red wine
The plant compounds glucosinolates are found primarily in cruciferous vegetables (the cabbage and cauliflower family). Known to help regulate metabolic function, inflammation, and stress responses, glucosinolates are most notably associated with cancer prevention. Studies done on mice and rats have found that glucosinololates, once broken down in the body, can deactivate carcinogens and guard cells against DNA damage.
Glucosinolates-rich foods include:
Phytoestrogens are so-called because they mimic the effects of estrogen in the body. For example, lignans are closely aligned with the prevention of hormone-associated cancers due to their estrogen-like effects. While the science is still inconclusive, researchers have found lignan intake to correlate with a reduced risk of postmenopausal endometrial cancer, and another study noted that women with high lignan consumption had lower rates of ovarian cancer (regardless of their menopausal status or overall age).
Researchers are currently studying the health applications of lignans on heart disease, osteoporosis, and prostate cancer in an effort to better understand the impact of this phytoestrogen. Other phytoestrogens are being explored in relation to relieving the symptoms of menopause like vaginal dryness, hot flashes, and mood disruptions.
Phytoestrogens like lignans are found in:
- Seeds (sesame, poppy, and especially flaxseeds)
- Whole grains (rye, oat bran)
Well-known after stories went viral about the resveratrol in red wine being good for heart health, this member of the stilbenoid phytonutrient family has been extensively studied. Resveratrol has been associated with what’s commonly called the “French paradox,” so-coined because many of the French people who consume saturated fatty foods and smoke cigarettes—alongside drinking a great deal of red wine—somehow enjoy long and healthy lives. Their longevity is attributed to resveratrol’s anti-inflammatory and antioxidant activity, and that’s not the end of resveratrol’s health benefits.
Resveratrol may also help slow down cognitive decline as we age. Animal studies have shown that resveratrol has neuroprotective effects. A study published in the American Journal of Clinical Nutrition found a similar effect on human subjects, namely that resveratrol helped to increase blood flow in the brain. Resveratrol is also being scientifically investigated in relation to type 2 diabetes treatment.
Dietary resveratrol can be found in:
- Cocoa and dark chocolate
- Grapes (specifically the grape skins)
- Red wine
Phytonutrients for Life
You don’t have to look far for these protective chemicals, because a normal diet of healthy eating that’s full of fruits, vegetables, whole grains, nuts, and seeds will provide you with a full deck of phytochemicals. Guard against chronic diseases, certain types of cancer, and promote good health with these essential nutrients and their amazing antioxidant properties.