polyphenols

What are polyphenols?

Polyphenols are a category of chemicals that occur naturally in plants. There are more than 500 unique polyphenols, also known as “secondary plant compounds.” These compounds have antioxidant properties and contribute to the bright colors of many fruits and vegetables.

Chemically, polyphenols have a structure that includes multiple phenol units. A phenol unit consists of a benzene ring and a hydroxyl group. The specific arrangement and number of these phenol units results in different classes of polyphenols.

The role of polyphenols in plants

Polyphenols play a crucial role in the growth and well-being of plants. These compounds are involved in various plant functions, including protection from ultraviolet radiation, defense against pests, and contributing to the color of the plant.

1. Protection against ultraviolet radiation: Plants, like humans, are susceptible to damage from excessive UV radiation. Polyphenols, especially flavonoids, absorb UV light and protect plant tissue from the harmful effects of UV-B radiation. This protective mechanism is essential for plant survival in environments with high UV exposure.
2. Defense against pests: Polyphenols are a part of the plant's immune system. They serve as a line of defense against insects, pests, and pathogens. Certain types of polyphenols are toxic to insects and can deter them from feeding on the plant. They also have antimicrobial properties that help the plant resist fungal and bacterial infections.
3. Contribution to plant colour: Polyphenols, especially anthocyanins, contribute to the bright colors of many fruits, flowers and leaves. These pigments are not only aesthetically pleasing, but also attract pollinators and thus contribute to plant reproduction.
4. Plant growth and development: Some polyphenols influence the growth and development of plants. For example, they can regulate cell division and differentiation and influence the action of plant hormones.

Occurrence of polyphenols in food

Polyphenols are abundant in a variety of foods, especially fruits, vegetables, grains and certain beverages. Foods rich in polyphenols:

Fruits: Berries such as blueberries, strawberries, raspberries, blackberries and cranberries are particularly rich sources. Other fruits such as grapes, cherries, lemons and grapefruit also contain significant amounts of polyphenols.

Vegetables: Including spinach, onions and artichokes. The polyphenol content can vary depending on the type of vegetable and the preparation method.

Cereals and whole grain products: Oats, rye and whole wheat are good sources of polyphenols.

Drinks: Some of the highest concentrations of polyphenols come from beverages. Green and black tea, coffee and red wine are particularly rich in polyphenols.

Benefits for humans: findings from human studies

Numerous human studies have investigated the potential health benefits of polyphenols.

Cardiovascular: Several studies suggest that a diet rich in polyphenols may help reduce the risk of heart disease.

Cognitive function: Further research has shown that polyphenols can have neuroprotective effects. Here A large study has already been conducted on older women using resveratrol.

Metabolism: Certain polyphenols, such as those found in green Tea (EGCG) and red wine (Resveratrol) can promote healthy digestion by supporting a favorable gut microbiome.

Bioavailability of polyphenols

The bioavailability of polyphenols, i.e. the extent to which these compounds can be absorbed into the bloodstream and utilized by the body, is a complex topicWhile polyphenols have shown numerous potential health benefits in research studies, their effectiveness in the human body is largely influenced by their bioavailability.

One of the biggest challenges in the bioavailability of polyphenols is that these compounds are often poorly absorbed in the intestineThis is due to their large molecular size and the presence of multiple hydroxyl groups, which make them less soluble in the aqueous environment of the digestive tract. In addition, polyphenols are extensively metabolized in the liver after their absorption, which can further reduce their bioavailability.

In addition, the bioavailability of polyphenols can vary depending on the type of polyphenol and the food source. For example, Flavonoids from citrus fruits are more easily absorbed than those from tea or onionsCooking and processing methods can also affect the bioavailability of polyphenols. For example, cooking vegetables can result in a significant loss of these beneficial compounds.

Despite these problems, there are several strategies to improve the bioavailability of polyphenols. Eating polyphenol-containing foods along with healthy fats can improve absorption, as fat increases the solubility of these compounds. Another approach is to consume foods that contain a variety of polyphenols, as some polyphenols can improve the absorption and utilization of other polyphenols.

In addition, technological progress opens up new possibilities for improving the bioavailability of polyphenols. For example, Encapsulation of polyphenols in nanoparticles or liposomes increases their solubility and stability and thus improve their absorption in the intestine.

Extraction processes for supplements

Polyphenols are commonly extracted from plant sources for use in dietary supplements using conventional methods such as solvent extraction, which uses organic solvents to dissolve the polyphenols. Although this method is widely used due to its efficiency and cost-effectiveness, but also poses some problems.

First, the use of organic solvents poses a health risk due to their potential toxicity.

Second, these extraction methods often require high temperatures that can degrade sensitive polyphenols, reducing their bioactivity and health benefits. Heating also causes to the formation of the proven carcinogenic Polycyclic aromatic hydrocarbons (PAHs), which ultimately remain in the finished product.

Another problem is the variability of polyphenol content and composition in plant materials, which can be influenced by factors such as plant variety, growing conditions and harvest time. This variability can lead to inconsistencies in the quality and efficacy of polyphenol preparations.

To meet these challenges, alternative extraction methods are being researched. A promising approach is fermentation with yeasts and other microorganisms.

Yeast fermentation offers several advantages over traditional extraction methods. It is a environmentally friendly, sustainable process, in which no toxic solvents or high temperatures need to be used, thereby preserving the bioactivity of the polyphenols.

Another benefit of yeast fermentation is the ability to produce consistently high-quality polyphenol extracts. Because the fermentation process is controlled and reproducible, it can reduce the variability associated with plant-based sources, resulting in more reliable supplements.

The best-known secondary plant substance Resveratrol can be obtained, for example, using this innovative method without harmful PAHs and with high purity (> 98%). The powder produced is also completely free of genetic engineering. Only a completely harmless slight yellowing of the final product indicates the manufacturing method.

Overdose of polyphenols: an underestimated problem

Although polyphenols are associated with numerous health benefits, Excessive intake may potentially lead to undesirable effects – a problem that is often overlooked in the enthusiasm for their positive qualities.

Excessive consumption of polyphenols can lead to interactions with medications and other substances. Polyphenols can also interact with certain medications and reduce their effectiveness. Caution is particularly advised for people taking anticoagulant medications.

In addition, certain polyphenols, when consumed in large amounts, can have pro-oxidative effects that lead to oxidative stress, a condition in which the body's antioxidant defenses are overwhelmed by free radicals that can damage cells and tissues, contributing to aging and various diseases. It is therefore important to pay close attention to the intake recommendations for any preparations.

In addition, some people may experience digestive discomfort when consuming large amounts of polyphenols, especially if they are not used to a polyphenol-rich diet. Symptoms may include bloating, flatulence, and stomach cramps.

Tip:: In this case, taking it together with a meal or something fatty (a spoonful of yogurt or oil) often helps. This not only increases tolerance, but also bioavailability!

To avoid these potential risks, it is important to consume polyphenols in moderation as part of a balanced diet.

Conclusion on polyphenols

Polyphenols, a group of phytochemicals found in many plant foods, have attracted a lot of attention due to their potential health benefits. From antioxidant and anti-inflammatory properties to their role in reducing the risk of chronic disease, the benefits of including polyphenols in our diets are many.

However, it is important to be aware of the potential risks associated with excessive polyphenol intake, including drug interactions, potential pro-oxidant effects, and digestive discomfort.