Synergy of Phytochemicals in Cancer Prevention

Jacob Schor, ND

October 1, 2007

 

 

I like pies. Apple, blueberry, peach, cherry. I've rarely met a fruit pie that I didn't like. On second thought, I have never met a fruit pie that I did not like. However, up to now, I've been a purist, believing fruits should be segregated, no intermingling of different fruits together in one pie. Well strawberry rhubarb being the single exception.   No one has any business slipping anything but apples into an apple pie. Those gourmet fruit combinations that are so modern, they are not for me.

 

Therefore, it is with great disgust that I am rereading a paper by one of my research heroes, Rui Hai Liu of Cornell University 's Food Science Department.

 

I've written ad nauseam already about the epidemiological studies that show high dietary fruits and vegetables are strongly associated with reduced risk of bad disease like cancer and heart disease. If this current research is true, it spells an end to my simple pie baking. My pies will be mixed fruits, as much as the idea seems a sacrilege and a perversion.

 

The world of nutrition used to be a much simpler world than it is now; fruits contained vitamin C and maybe a few other vitamins. Period. In our new world, vitamin C barely rates mention. It's the phytochemicals that count. Over 5,000 different phytochemicals from fruits and vegetables have been isolated, identified and named and there seems to be no shortage of interest in finding more. A huge number are still unknown.

 

Scientists classify these chemicals into various groups, the details of which are probably not that relevant. Yet since the names of these groups get thrown about into advertisements, papers, discussions and conversations all the time, it would be worth sorting through them at least briefly. Maybe not in enough detail so that we know what we are talking about but at least to guess if someone else does.

 

We divide the phytochemicals into five main groups:

  1. Carotenoids
  2. Phenolics
  3. Alkaloids
  4. Nitrogen containing compounds
  5. Organosulfur compounds

 

Carotenoids are pigments: they make a carrot orange, a tomato red and corn yellow. Some, like betacarotene get lots of attention because of their provitamin and antioxidant status. About 600 different carotenoids have been identified.

 

Organosulfur compounds are what makes the smellier vegetables, garlic, cabbages and such, smell the way they do.

 

The phenolics are all compounds with one or more aromatic ring and one or more hydroxyl group attached. These chemicals are the result of secondary metabolism in plants: they often take care of essential functions acting to defend against pathogens and parasites. Phenolics are divided into five more categories:

  1. phenolic acids
  2. flavonoids
  3. Stilbenes
  4. Coumarins
  5. Tannins

 

Of these, the flavonoids are further subdivided into another half dozen categories with names that will drive your spell check mad:

  1. flavonoids
  2. flavones
  3. flavonols
  4. flavanones
  5. anthrocyanidins
  6. isoflavonoids

 

So, for example, when we talk about quercetin, it is a flavonol, a type of flavonoid, which is a phenolic phytochemical.

 

Scientists looking for the cure to cancer and everything else that ails anybody have been hoping to find the single phytochemical that will act as a magic bullet. Though we certainly have exciting data on particular chemicals it looks more and more like it's the interaction of a multitude of these chemicals that really does the magic.

 

The pie wrecker Liu writes:

“It is now widely believed that the actions of the dietary supplements alone do not explain the observed health benefits of diets rich in fruits, vegetables and whole grains, because, taken alone, the individual antioxidants studies in clinical trials do not appear to have consistent preventive effects. The isolated pure compound either loses it bioactivity or may not behave the same way as the compound in whole foods.”

 

For years, we mistakenly considered vitamin C to be the primary antioxidant in fruits. All our focus in food processing was how to best preserve the vitamin C. Heat destroys vitamin C, so cooking food became equated with destroying its antioxidant effect. It turns out that vitamin C is only one of many antioxidants found in fruits and vegetables. The phytochemicals often play a much larger role.

 

Here is an example from Liu's research.

An apple contains about 5.7 mg per 100 grams of vitamin C. Yet the antioxidant effect of the various phytochemicals in the apple is equivalent to 1500 mg of vitamin C. The vitamin C in an apple accounts for less than 0.4% of the antioxidant effect. Cooking the apple, say in making applesauce, actually increases antioxidant effect. One can argue, based on Liu's published research, that an apple pie has more antioxidant effect than raw apple juice made from a similar quantity of apples. See why this fellow is high on my list.

 

Combining different fruits together increases the total antioxidant effect in a synergistic manner. For those of you who are too young to remember Bucky Fuller, synergy refers to a phenomenon in which the whole is greater than the sum of the parts. In this case, if you combine oranges, apples, grapes and blueberries into one mush, it will have a greater synergistic antioxidant effect than if you added up and totaled the individual effects of each of these fruits. The effect of the combined fruits increased by a factor of five over what simple addition would predict.

 

Nutrition experts have encouraged us to eat a wide variety of fruits and vegetables for years. This brings the message home. No more straight blueberry pie; I've got to bake mixtures of blueberry, raspberry cherry all cobbled together. This does not make me happy.

 

There is another way to interpret this research. Never eat a slice of just one pie, always have at least a taste from several different pies. The more pies you taste, the healthier they get for you.

 

This synergistic effect goes far to explain the failure of the experimental trials in which a single food or vegetable was singled out for testing. A single food will only give you the benefit of that single substance which without synergistic multiplication may not be enough to matter. In a diet with multiple phytochemicals mixed together, synergy can increase their benefit to the point that it matters.

 

Time for a recipe:

My general opinion about adding much anything besides apples to an apple pie is obvious. It is in vogue these days, so please go ahead. I intended to provide a recipe for anapple, pear, cranberry raisin walnut pie with this newsletter but when it came to turning on the oven to bake it this weekend, I couldn't bring myself to do it. On the other hand, I do really do like fruitcake.

 

Therefore, here is a basic fruitcake recipe using dried (not candied) fruits. The trick that I learned from Cooks Illustrated is to presoak the fruit with the alcohol. This shortcut allows you to skip the weeks of soaking cheesecloth wrapped loaves with rum in the hope of impregnating them with alcohol. Instead, the rum leaches out of the fruit, soaking the cake quite adequately. These loaves taste fine the day baked, but improve nicely with time

 

Synergistic Fruit Cake

 

5 cups of mixed dried fruits, the bigger ones chopped to small pieces. The more different fruits used, the better you can rationalize that this is good for you to eat. For example:

1 cups raisins

one half cup pitted prunes chopped

1 cup pitted dates chopped

1 cup dried cherries

one half cup dried cranberries

1 cup dried apricots chopped

 

 

Mix fruits together with

1 cup dark rum and let sit overnight to soak

 

2 sticks butter (half pound)

beat butter and then add following ingredients one at a time, mixing well

 

4 eggs

one cup molasses or honey or better to use a little bit of each

one half cup strong coffee or orange juice concentrate

2 teaspoons vanilla

 

Sift together,

2 cups flour

1 teaspoon nutmeg

1 teaspoon allspice

1 teaspoon ginger

2 teaspoons cinnamon

one half teaspoon salt

 

 

Mix sifted flour into butter and egg mixture. Then fold in the fruit and rum mixture and then

1 cup toasted chopped pecans or walnuts

 

Fold in the nuts

 

Bake at 300 degrees for an hour to hour and a quarter. The loaf tops should feel firm to pressure.

 

 

 

 

 

 

Rui Hai Liu . Potential Synergy of Phytochemicals in Cancer Prevention: Mechanism of action. The Journal of Nutrition 2004