They are found in fruits, vegetables, legumes, nuts, and whole-grain products: phytochemicals. In plants, they serve as protection against predators, germs, bacteria, and diseases, as well as harmful UV light. They are responsible for the plants’ color, aroma, and flavor. As effective nutrients for human health, they are now increasingly coming to the forefront. They are considered highly potent antioxidants and have anti-inflammatory and antibacterial effects. According to estimates, there are more than 50,000 secondary plant compounds. Among their best-known examples are carotenoids, anthocyanins, and polyphenols, which also include flavonoids. Well-researched and particularly valuable secondary plant compounds are found, for example, in carrots, tomatoes, krill oil, green tea, ginkgo, pumpkin and red wine grape seeds, blueberries, and cranberries.
Valuable Antioxidant: Astaxanthin
Krill, salmon, and flamingos—they all owe their pink color to the carotenoid astaxanthin, which occurs naturally in microalgae. It enters the bodies of animals and humans through the food chain. Astaxanthin is considered one of the strongest antioxidants. It can neutralize free radicals right at the cell membrane, thereby providing active cellular protection. Studies have shown that this valuable carotenoid is responsible for several health-promoting effects. It can support eye health and boost the immune system, and it helps the body combat cardiovascular diseases. People who are physically active also benefit from this phytochemical. A scientific study from Sweden found that physical performance—particularly strength and endurance—can be enhanced by astaxanthin. Athletes who take astaxanthin report faster recovery after training, less pain, and fewer injuries during intense workouts.
Natural Skin Protection
Just like lycopene, astaxanthin can help provide natural skin protection. During intense sun exposure, the skin produces more free radicals. This can lead to damage and premature skin aging. A particularly good source of astaxanthin is high-quality krill oil. It is extracted from small crustaceans native to the clean waters of Antarctica. Krill oil naturally contains astaxanthin and omega-3 fatty acids, which are bound to phospholipids.
The Eye Specialists: Lutein and Zeaxanthin
The two essential nutrients, lutein and zeaxanthin, are concentrated in the human eye’s “yellow spot,” known as the “macula lutea.” This is the area of the eye with the highest visual acuity. Both carotenoids support healthy metabolism, absorb harmful UV radiation, and neutralize free radicals. They act, in a sense, like “internal sunglasses.” Numerous studies indicate that both of these essential nutrients play an important role in the prevention of serious eye diseases. These include, among others, cataracts and age-related changes in the retina, such as age-related macular degeneration (AMD), which can lead to a decline in vision as we age. Lutein and zeaxanthin cannot be produced by the body itself and must be obtained through the diet. There is scientific evidence suggesting that the body can convert the carotenoid lutein into zeaxanthin when needed. Lutein, zeaxanthin, and astaxanthin structurally belong to the same family as beta-carotene. They are found in particularly high concentrations in kale, parsley, spinach, broccoli, leafy greens, peas, Brussels sprouts, green beans, corn, raw carrots, and tomatoes.
What does “secondary” mean?
There are primary plant compounds such as fat, protein, and carbohydrates, from which secondary plant compounds are produced through the plant’s own metabolism (secondary metabolism). In all plant-based foods, such as fruits and vegetables, they serve protective functions, such as shielding against UV light. They are found in the outer layers of plants, in the skin, and in the outer leaves. That’s why an apple should be eaten with the peel whenever possible, since that’s where most of the secondary plant compounds are found. Some secondary plant compounds are toxic to humans in their natural state. That’s why certain vegetables, such as beans, should not be eaten raw.
Topic: Bioavailability
Phytochemicals such as carotenoids that are consumed with oil are particularly bioavailable to the human body. This also applies to dietary supplements containing phytochemicals dissolved in oil. A particularly good example of this is 100% natural krill oil, as this fish oil naturally contains the carotenoid astaxanthin.
