The cabbage family is not the only group of foods that has shown potential to block the cancer process. Other foods may also have this ability – and some may be even more potent than foods of the cabbage family.

But the evidence for these other foods is not as strong. Some foods have inhibited cancer in studies on animals, but studies with humans have yet to be done. Other foods have been studied in only one or two experiments – too few for judgment. This is why some health institution such as Committee on Diet, Nutrition, and Cancer limited its recommendations to the cabbage family.

Of the other foods that might also contain inhibitors, the evidence is best for citrus fruits. The beneficial effect of these foods has ranged from weak to potent in studies with animals.

As for other foods, the evidence is just beginning to come in. But for your information, I would like you to know some of the possibilities now under further study:

• Celery and spinach have shown slight but significant inhibiting ability.
• Soybeans and lima beans have also shown some potential.
• Grains and vegetable oils may contains a substance with moderate inhibiting power.
• Green coffee beans have shown a powerful inhibiting effect in early studies. But roasted and instant coffee have shown only a weak effect.

Remember: for some of these foods only several studies have been done. This is far too little work to justify changing your diet.

Some Unanswered Questions

Scientists are still a little cautious about the cancer inhibitors in food. They aren’t 100 percent convinced that these substances are only beneficial.

The Committee on Diet, Nutrition, and Cancer tells us that its matter of weighing the pluses and minuses. On the balance, the panel scientists agrees that the good points of the cabbage family vegetables outweigh the bad points.

What are the bad points? Mostly, they fall under the label of “uncertain effects.”

As noted earlier, inhibitors seem to activate an enzyme system that is thought to detoxify harmful chemicals. There is some concern that this very same enzyme system may also enhance the power of some chemicals. In other words, the enzyme system may have both good and bad effects.

Despite information on this subject is incomplete, still,  the scientists recommend that we eat citrus fruits, whole grains, and cabbage family vegetables. Obviously, the scientists think that the pluses here outweigh  the minuses.

But until this question is settled, it is best not to go all out with cabbage family vegetables. Eating them often – but not exclusively – is probably the best course of action. Including them in your diet once or twice a week is a cautious, moderate approach.

Putting It All Together

Up to this point, you have read a great deal about fruits, vegetables, and grains. It is fitting, I think, to take a broad look at these foods to see how they score when all protective factors are taken into account.

There are four factors to consider: vitamin A, vitamin C, insoluble fiber, and inhibitors. To take a simple approach to these four factors, I have devised a rating system.

I gave a food one point if it contains a moderate amount of vitamin A and two points for a high level. I used the same system for vitamin C and for insoluble fiber.

I then awarded two points to the four members of the cabbage family that appear to contain a cancer inhibitor other than vitamin A and C or fiber. I gave one point to the other foods that might have a cancer inhibitor.

The Top-Scoring Cancer-Blocking Foods

When all the points were tallied, broccoli and brussels sprouts topped the list.

They were followed by some vegetables that many people eat little of: collards, kale, kohlrabi, mustard greens, and rutabagas.

But in third place were some familiar faces: oranges, grapefruit, cabbage, cauliflower, lima beans, and spinach. Watercress also rated with this group.

Chances are that you like some of these foods. Pick the ones you like best, and continue to enjoy them.