Phytochemicals – a term for daily use

It’s time to talk about phytochemicals, and make this term a household name.

Just think about it: it sounds like a plot, an animal conspiracy to insure the untimely demise of carnivores and longer lives of vegetarians: the more animal foods people eat, the greater their risk of dying from chronic diseases such as heart disease, cancer and diabetes. When people switch to a plant based, whole foods diet, their risk for such diseases miraculously diminishes.

By now, many people know about the benefits of adding fruits and veggies to their diets: plant foods are low in saturated fats and completely free of cholesterol. Plant foods are rich in fiber – animal foods are 100% fiber-free. The proteins in plant foods PROTECT against heart disease and kidney disease, while animal protein INCREASES exactly those risks. Fruits and vegetables are rich in antioxidant nutrients like vitamin C, E and beta-carotenoids.

But just when you thought, we knew all there was to know, in come the PHYTOCHEMICALS.

Phyto is Greek for “plant”; these are the naturally occurring chemicals that are responsible for the flavor, color, smell and texture in all fruits and vegetables. While phytochemicals are not currently considered essential nutrients, volumes of research studies are accumulating to support their strong and consistent beneficial effects on health.

Phytochemicals are not there for OUR benefit, but for the plants’: they help regulate plant growth and protect the plants from disease and insects. How lucky for human kind that exactly THOSE compounds work miraculous wonders for the human body. NO component in ANY animal food does that – another proof that humans were meant to consume primarily plant foods.

While veggies and fruits are considered our primary sources of phytochemicals, many legumes, whole grains, nuts, seeds, herbs and spices provide impressive contributions to our intakes. Tens of thousands of phytochemicals are scattered throughout the plant kingdom. The largest category of phytochemicals is PHENOLIC compounds, a group of over 4000 different chemicals. Within this category, there are several subgroups, the three most important being:

  • Flavonoids: concentrated mainly in veggies, fruits, green tea and soybeans.
  • Phenolic acids: found mainly in whole grains, berries, cherries, grapes, citrus and other fruits.
  • Tannins: found in lentils and other legumes black and green teas, grapes and wine.

Phenolic compounds have been found to have powerful antioxidant, anticancer and anti-cardiovascular disease effects.

Another large and extremely powerful group of phytochemicals is TERPENES. They include

  1. Carotenoids (lykopene, beta-carotene and lutein) found in carrots, tomatoes, leafy green vegetables and other fruits and veggies
  2. Limonoids found in citrus fruits

In addition to the a fore mentioned powerful antioxidant, anticancer and anti-cardiovascular disease activities, these compounds reduce the effectds of aging and macular degeneration of the eyes.

A third major category of phytochemicals is the SULFUR-CONTAINING CHEMICALS such as

  1. Organo-sulfur compounds found in garlic
  2. Isothiocyanates, such as sulforaphane (view my previous post in this) in cruciferous vegetables.

These compounds have powerful anticancer and immune-enhancing abilities which have been demonstrated in the lab as well as in large population based studies.

What makes matters complicated – and VITALLY IMPORTANT – is that phytochemicals must act syngergistically for their effect, in order to produce the benefits observed. That is why they must be consumed as WHOLE food nutrients, and not as synthesized powders or pills, where their effects are NOT present. While interest in phytochemicals has spurned a whole new market for supplements and designer foods, NONE of these have shown the benefits observed from consuming the WHOLE food containing these substances: in fact, isolated administration of vitamin E was found to increase the risk of death when administered as a synthetic supplement.

While some foods stand out as real powerhouses, variety is the real key to a phytochemical-rich diet. Aim to make these foods part of your daily, regular meals, and you will have a phytochemical feast!

Watch out for my next blog; lots of examples on how to build a phytochemical feast at every meal!


  1. Miller ER et al.: Meta-analysis: high dose vitamin E supplementation may increase all-cause mortality. Annals Int Med; Jan 2005: vol 142, p 37-46
  2. King A et al.: Characteristics and occurrence of phenolic phytochemicals. J Am Diet Assoc 99,2 (1999), 213-218
  3. Hughes JS: Understanding phytochemicals in fresh fruits and vegetables. ISHS Acta Horticulturae 875: 2009 Southeast Asia Symposium on quality and safety of fresh and fresh cut produce
  4. Khawaja O. et al: Chocolate and coronary heart disease: a systematic review. Current Atherosclerosis Reports, Vol 13, No 6 (2011), p. 447-452
  5. Davis B. et al: Becoming vegan. The complete guide to adopting a healthy plant-based diet. Book published by Book Publishing Company, 2000