The Power of Phytochemicals

As promised, a phytochemical is a naturally occurring plant chemical that protects plants from disease. It’s found in fruits, vegetables, legumes, whole grains and nuts. Evidence also points to phytochemical’s as having disease-fighting properties (e.g., anti-cancer) that also protect humans.

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Last week I asked,  “Is a phytochemical the same thing as an antioxidant?” Here’s the answer – some phytochemicals are antioxidants (meaning they prevent oxidative damage) but not all are. However, even if a phytochemical is not an antioxidant, it is still beneficial, it just works in a different way than scavenging free radicals.

Let me throw out some names of phytochemicals just to make you familiar, but please don’t worry about memorizing them!


  • Carotenoids
  • Flavonoids
  • Polyphenols
  • Tocotrienols

Possible Ways Phytochemicals May Work:

  • Antioxidants effects (scavenge free radicals).
  • Effects on cell differentiation (helps a cell when it starts to become different from the original).
  • Increases activity of enzymes that detoxify carcinogens.
  • Blocks formations of nitrosamines (which are carcinogens).
  • Preserves integrity of intracellular matrixes (keeps our cells intact).
  • Promotes maintenance of normal DNA repair (when carcinogens alter the cell’s DNA).
  • Increases apoptosis (spontaneous death of cancer cells).
  • Decreases cell proliferation (cancer cell division).

THEORY – Synergistic Effect

Each fruit, vegetable, whole grain, legume has hundreds of different phytonutrients that work together to increase disease-fighting potential. Research studies that focused on individual antioxidants (or phytonutrients) have shown mixed results & have not proved protective against cancer. Research has not determined a true “why” for this, but it is an area of continuing investigation.

There are many possible reasons:

  • Perhaps individual components may not work in isolation.
  • Perhaps antioxidants and phytonutrients in supplement form simply don’t have the same cancer-protective effects as a diet high in fruits and vegetables.
  • Perhaps different forms of the antioxidant not used for the research study are the beneficial part.
  • Perhaps the different forms of the antioxidants need each other to work.
  • Perhaps there’s an unidentified beneficial compound.
  • Perhaps it has something to do with genetics.

*The list goes on!

Take Away Tips:

  • Eat a variety of plant-based foods like fruits, vegetables, whole grains, beans/legumes, Eat The Rainbow Photonuts/seeds, herbs/spices,coffee/tea. The AICR (American Institute for Cancer Research) recommends consuming 4-5 cups of fruits and vegetables daily. Eat the RAINBOW and include WHITE fruits & vegetables (pears, white peaches, cauliflower, onions, etc.)
  • Choose whole foods instead of taking supplements!

Wendy for Blog

Wendy Kaplan, MS, RDN, CDN is a registered dietitian nutritionist specializing in oncology and weight management. She is also the Nutrition Consultant/Educator for Mondays at Racine Cancer Care Foundation, a 501c3.  Connect with Wendy on FacebookInstagram and Twitter and read more of her blog posts at #WellnesswithWendy