Polyphenols: Antioxidants Series, part 6

We are nearing the end of the seven-part Friday Five Antioxidant Series.  In part 6 we are looking at polyphenols – what they are, what they do, and where to find them.

Antioxidants Venn-style

1 What are they?

Polyphenols are compounds that are thought to reduce inflammation and support digestion, brain health, heart health and more.  They are even thought to be involved in the regeneration of some vitamins.

More than 8000 types of polyphenols have been identified, they have been put into four main groups: flavonoids, phenolic acids, stilbenes and lignans.

It is important that we try to protect our gut health in order to absorb most forms of polyphenols.  Most of the compounds undergo processes involving gut bacteria and enzymes within the intestines before we absorb them.

2 How do polyphenols work as antioxidants?

Polyphenols not only suppress the generation of free radicals, they are also believed to neutralise some free radicals making them stable and unreactive.

Additionally, polyphenols are also thought to bind to metals in the body (for example iron) helping to reduce oxidation caused by the highly reactive hydroxyl radicals.

3 Are all polyphenols beneficial?

While the pros are certainly believed to outweigh the cons of polyphenols, some are thought to have less beneficial effects on nutrient absorption, in particular tannins.  Some types of tannins have been found to interfere with our absorption of iron.  These tannins are found in foods and drinks such as black tea and oregano – try to avoid regularly drinking tea with meals, especially if you have a low iron intake or are prone to low iron levels.

4 Sources

While the ripeness, growing conditions and preparation can affect the polyphenol content of food, you can find them in most plant foods.  Some particularly good sources include:

  • Cocoa powder – yes, dark chocolate. The richer the chocolate this higher the polyphenol content so go from varieties that contain at least 70% cocoa solids.
  • Berries – in particular strawberries, blueberries, blackberries and raspberries
  • Blackcurrants
  • Plums
  • Cherries
  • Nuts – particularly hazelnuts and pecans
  • Artichokes

One of the best ways to ensure you get a good range of polyphenols is to Eat the Rainbow.

5 Food preparation

The level of polyphenols in food can be affected by how the food is prepared.   Research has shown that processing of plant foods contributed to notable reductions in the polyphenol content.    Even steaming or boiling the foods may halve their level of this useful compound.  In terms of sensitivity a review found potatoes were least sensitive to polyphenol loss, while peas and beans were much more sensitive.  However, a study that focused on a variety of ‘green beans’ found that more polyphenols were retained with steaming than boiling.

The extent of the damage to polyphenols in food varies between food type, preparation, cooking method and temperature.  Wherever possible, eating fresh, whole, raw plant foods may be the most beneficial in terms of polyphenol antioxidants.

Important

If you are considering taking nutritional supplements, please consult with a suitably qualified professional to ensure the supplement is appropriate for you.  This is especially important if you have any health conditions or are taking medications.

Alible Nutrition Nutritional Therapy services consider health conditions and medications prior to providing advice regarding foods or supplements.

Are you eating enough fruit and veg?

If you would like to introduce more fruit and veg into your diet to increase your nutritional intake, and you have no health concerns, why not book in for a Nutritional Review?  We will take a look at your diet, your nutritional intake, and ways that you can improve.

If you have health concerns, a Nutritional Therapy package may be more suitable for you.

References/Further Reading