Botanical Power

Botanical Power

by Heather Granato

Behold the power of plants. Beyond just offering taste and basic nutrition, many fruits, vegetables and botanicals offer an array of antioxidant compounds. They help bolster innate defenses and supply nutrients that target damaging free radicals.

Interestingly, it is often the pigments in plants that are responsible for their powerful antioxidant effect. This can be attributed to their innate function; antioxidant carotenoids (fat-soluble pigments) and flavonoids (water-soluble pigments) help protect plants from the oxidative damage incurred by UV radiation, microbial attack and other external contaminants. [For more information on the power of flavonoids, click here.] Carotenoids include the xanthophylls (e.g., zeaxanthin, lutein, astaxanthin) and the carotenes (e.g., alpha-carotene, beta-carotene, lycopene). They can quench singlet oxygen, as they do in plants, and scavenge free radicals to prevent or terminate oxidative chain reactions.

French researchers noted the ability of carotenoids to inactivate reactive oxygen species (ROS) may be responsible for their ability to prevent the development and progression of chronic diseases such as cardiovascular disease (CVD) and cancer.¹

It appears carotenoids protect DNA in the body. A study from the United Kingdom found healthy volunteers who received carotenoid supplementation had increased activity in DNA repair following an oxidative challenge.² Additional research by the same team from Norwich Research Park examined the ability of beta-carotene, lutein and lycopene to protect DNA from oxidative damage in both a cell culture and human model.³ Both studies found the carotenoids scavenged DNA-damaging free radicals and modulated DNA repair mechanisms.

Development of CVD has been linked to oxidative damage of cholesterol, leading to plaque formation. Because carotenoids are transported by lipoproteins, it is suggested that they might protect blood lipids against oxidation. In vivo and in vitro work by French researchers showed carotenoids can transfer between lipoproteins preferentially.⁴

Specifically, lutein was found to protect against atherosclerotic development in mice models,⁵ while beta-carotene and astaxanthin both inhibited peroxidation of lipids.⁶ In fact, astaxanthin was shown in a study at the National Institute of Health and Nutrition in Tokyo to significantly inhibit LDL (low-density lipoprotein) oxidation in 24 volunteers.⁷

Lycopene also offers significant protection against LDL oxidation, according to researchers from Brigham and Womens Hospital in Boston.⁸

Carotenoids antioxidant power is also obvious in its protection of the eyes, which are constantly exposed to high levels of UV radiation. As such, the greatest levels of lutein and zeaxanthin occur in the eye, where they absorb blue light (to protect the photoreceptor cell layer) and scavenge singlet oxygen. Supplemental lutein and zeaxanthin increase macular pigment density, filtering greater amounts of short-wave light and reducing the effects of oxidative damage.⁹

Beyond produce, many botanicals offer special support against oxidative damage. Consider the contribution of culinary and medicinal herbs. Norwegian researchers assessed the contribution of these herbs to the estimated daily intake of dietary antioxidants, and found a more than 1,000-fold difference among the antioxidant concentrations of various herbs.¹⁰ For example, oregano, sage, allspice and cinnamon all contained high concentrations of antioxidants, and may contribute significantly to the total intake of antioxidants from the diet. Similar findings were reported out of the University of California, Davis, in which thyme, basil and rosemary had the highest antioxidant activity in lipophilic assays.¹¹

Rosemary and sage have been found through in vitro studies to have extensive antioxidant power. For example, a study of the distribution of different compounds within rosemary showed extracts containing phenolic diterpenes, caffeoyl derivatives and flavones worked in both aqueous and lipid systems.¹² Similarly, investigations of sage and Greek oregano showed ethanol and acetone extracts of the herbs had high concentrations of phenolic antioxidants.¹³

Beyond the culinary field, botanicals such as ashwagandha (Withania somnifera)classified in Ayurveda as a rasayana, which promotes overall wellnessalso contribute to the antioxidant toolbox. A study from Kurukshetra University in Haryana, India, found ashwagandha inhibited lipid peroxidation in a dose dependent manner in rats.¹⁴ General studies have shown ashwagandha has antioxidant, anti-stress, anti-inflammatory and immunomodulatory activities.¹⁵

For a full list of references to this story, click here.

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