Phytonutrients – Hooray for a Plant-Based Diet

October 22, 2013 in Antioxidants, Health Claims, Nutrition by Joyce Bunderson

When you see the word phytonutrients or phytochemicals, does it just look like a scientific word and your eyes roll back a bit? In September’s issue of RD Today’s Dietitian, Denise Webb PHD RD has written an article called Phytochemicals’ Role in Good Health. The article has given me the impetus to write a short article on phytonutrients. So today I thought that I’d spend a bit of time making a little better introduction to the word, phytonutrients.

To begin, phyto means plant in Greek. This part of the story is really quite simple. Saying a certain compound is a phytonutrient or phytochemical is just saying that it is something derived from a plant. There is an abundance of research that shows that consuming foods with phytonutrients is related to the prevention of disease. The science regarding phytonutrients is in its infancy; but having said that, I will say that there is lots of evidence that these nutrients have been found to be related to lower risk of cancer, cardiovascular disease (by lowering blood pressure, decreasing LDL and/or increasing HDL cholesterol, dilating blood vessels, decreasing the tendency of the blood to form clots and reducing inflammation); type 2 diabetes (by reducing inflammation, improving insulin sensitivity, and indirectly by preventing weight gain – especially the intake of whole grains and dark green leafy vegetables); and neurological diseases like Alzheimer’s disease and Parkinson’s disease. Four of the main studies that researchers cite for the risk reduction are the following: (1); (2); (3); and (4).

Phytonutrients are found in plants, in addition to the carbohydrates, protein, fat, fiber, minerals and vitamins that they contain. The phytonutrients are responsible for the color, flavor, and odor of plant foods. They are found in whole grains, legumes, beans, vegetables, fruits, herbs, spices, nuts, and seeds.

Phytonutrients are classified into groups; some of the most common groups that you may have read about are Carotenoids (lycopene, beta-carotene, and hundreds of others), Anthocyanins, Flavonoids, Sulfides and Isoflavones. Different foods provide different phytonutrients and the different groups of phytonutrients seem to have different, although overlapping benefits. There are tens of thousands of phytonutrients that have already been identified and researchers have good reason to claim that there are many more yet to be discovered.

An interesting fact about phytonutrients is that some of the phytonutrients produced by a plant are to protect itself from the environment. So when a plant has more environmental stressors the plant produces more phytonutrients. So plants vary in the amount of a specific nutrient, based upon the growing conditions. For example, when leaves are stressed in the fall with less water and cold temperatures, they turn bright colors. This is due to the production of Anthocyanins that protect the increasingly fragile leaves from sunburn, and keep them functioning longer.  Certain phytonutrients can safeguard our cells against stress as well.

While the science of phytonutrient research is still in its infancy, we know quite a bit about the associations between diets high in plants and disease reduction. However, we still do not know very much about specific single phytonutrients and reduction of disease. One of the main questions that has not been answered is whether the disease reduction is related to the single action of a specific phytonutrient or in combination with numerous phytonutrients and vitamins and/or minerals or the fiber found in the same plant food.

Because the action of individual nutrients in a whole food containing phytonutrients cannot be singled out, it makes good sense to eat the whole food. So we are often advised to eat more whole foods such as berries, grapes, or peanuts, or some complex ingredients, such as dark chocolate, the spice turmeric found in curcumin, or capsaicin found in red peppers. Maybe one day we’ll understand individual phytonutrients; but for now, we can best get the benefits by eating the whole foods.

Certainly, those who grow specific crops, all tout their particular product. And well they might, as there are many different benefits. Not only can we not single out the effects of single phytonutrients, we still have a lot of work to classify the benefits of different phytonutrients. Consider this list of benefits by Denise Webb:

  • Stimulating the immune system,
  • Preventing toxic substances in the diet from becoming carcinogenic,
  • Reducing inflammation,
  • Preventing DNA damage and aiding DNA repair,
  • Reducing oxidative damage to cells,
  • Slowing the growth rate of cancer cells,
  • Triggering damaged cells to self-destruct (apoptosis) before they can reproduce,
  • Helping to regulate intracellular signaling of hormones and gene expression,
  • Activating insulin receptors.

She adds that there are likely health effects of phytonutrients that the researchers haven’t yet discovered.

It is fairly difficult, if not impossible to follow each study, which chooses one phytonutrient, from a specific food source, and then write recommendations.  Instead you may want to consider trying variety; frequent vegetable intake, plus a large amount of vegetables.  This is why it’s hard to fit in lots of junk food ‘cause we need the space to frequently fit in lots of veggies.

Variety has been known and publicized for so many decades. Eating a large variety of plant foods has repeatedly been shown to be healthful. One mechanism is that it reduces the chance of too much of a certain component of food and another is probably that it increases the opportunity of phytonutrients that work together of being available.

Heads up: If you’re frequently choosing a fast food chicken sandwich or burger with its skimpy slice of lettuce, white bread bun, paper thin tomato, drop of catsup and a slice or two of pickle to nourish yourself; it may make it fairly difficult to really get an abundance and variety of phytonutrients. Give yourself a chance with phytonutrients and lots of them. A plant-based diet makes stocking up on phytonutrients effortless.