Phytonutrients (also known as secondary plant compounds) are bioactive compounds found in plants that give them color, flavor, and protection from pests. Although they are not essential for humans like vitamins or minerals, they have numerous health benefits.
Important groups of phytonutrients and their effects
- Carotenoids (e.g., beta-carotene, lutein, lycopene)
- Found in: carrots, tomatoes, spinach
- Effect: Antioxidant, protects the eyes, strengthens the immune system
- Flavonoids (e.g., quercetin, kaempferol)
- Found in: berries, onions, green tea
- Effect: Anti-inflammatory, supports the cardiovascular system
- Glucosinolates
- Found in: broccoli, cabbage, mustard
- Effect: Anti-inflammatory, supports the cardiovascular system
- Saponins
- Found in: Legumes, oats
- Effect: Lower cholesterol, antibacterial
- Phenolic acids (e.g., caffeic acid)
- Found in: coffee, whole grain products
- Effect: Antioxidant, anti-inflammatory
- Lignans
- Found in: flaxseed, sesame seeds
- Effect: Hormone-regulating, possibly cancer-inhibiting
There are clear links between phytonutrients and epigenetics. Epigenetics refers to changes in gene expression that are not caused by changes in the DNA sequence itself, but by chemical modifications of the DNA or histone proteins, such as:
- DNA methylation (adding methyl groups to DNA to activate or deactivate genes)
- Histone modifications (changing the packaging of DNA to facilitate or hinder access for transcription factors)
- Regulation by microRNAs (influencing gene expression through small RNA molecules)
How do individual phytonutrients influence epigenetics (examples)?
- Curcumin (from turmeric)
- Inhibits DNA methyltransferases (DNMTs), which are responsible for methylation.
- Influences histone modifications and microRNA expression.
- Can activate anti-inflammatory and anti-cancer genes.
- Resveratrol (from red grapes, red wine)
- Activates sirtuins (SIRT1), which are associated with longevity and cell protection.
- Regulates histone modifications and influences genes associated with aging and metabolism.
- Sulforaphane (from broccoli, cabbage)
- Influences the expression of tumor suppressor genes by inhibiting DNA methylation.
- Supports detoxification and cell protection mechanisms.
- Genistein (from soy)
- Modifies DNA methylation and histone acetylation
- Reduces the risk of hormone-dependent cancers such as breast and prostate cancer
- EGCG (epigallocatechin gallate, from green and white tea)
- Inhibits DNMTs and reactivates suppressed tumor suppressor genes.
- Influences microRNA regulation and has anti-inflammatory effects.
Health relevance of these epigenetic effects
- Cancer prevention: Many phytonutrients reactivate tumor suppressor genes or inhibit cancer-promoting genes.
- Aging & longevity: Sirtuins (such as SIRT1) play a key role in cell aging and can be activated by certain nutrients.
- Metabolic diseases: Phytonutrients can influence epigenetic mechanisms associated with diabetes and obesity.
- Neuroprotection: Some compounds (e.g., curcumin, resveratrol) have neuroprotective effects through epigenetic regulation and may reduce the risk of Alzheimer’s and Parkinson’s disease.
Phytonutrients have the potential to epigenetically modulate our genes and thus act preventively against various diseases. A diet rich in plant-based foods can therefore positively influence not only our current health, but also our genetic predisposition and thus our longevity.