In February 1984, the American Cancer Society announced nutritional guidelines that made cruciferous a household word.

You remember the guidelines: avoid obesity; cut down on total fat intake; eat more high-fiber foods such as whole grain cereals, fruits and vegetables; include foods (not supplements) rich in vitamins A and C; increase consumption of cruciferous vegetables such as broccoli, cauliflower and Brussels sprouts; limit salt-cured, smoked and nitrate-cured foods; be moderate in alcohol consumption.

Now comes a book by Dr. Oliver Alabaster that gives you the scoop on the research that generated these guidelines, information on how to assess your cancer risk, and guidance on how to bring your diet into line with the new knowledge.

Alabaster, an oncologist and head of cancer research at George Washington University Medical Center, says scientific studies reveal that about 60 percent of cancer in women and 40 percent of cancer in men could be due to dietary factors. "Since more than a quarter of the total population will eventually develop cancer," he writes, "this means that about 60 million Americans will be affected. Of these, approximately 20 million cases might be prevented by relatively simple changes in the national diet!"

Sounds like great news. And, in fact, some day it might be. But not yet. There are no sure answers, only increasing "evidence" that points up "associations" between certain dietary factors and the prevalence of certain cancers.

Alabaster does an excellent job explaining to the lay reader some of the knotty problems and exciting insights coming out of cancer research. Proving the connection between diet and cancer, a feat that depends on the ability of science to unravel complex interactions of chemicals within foods and in the body, is a central problem.

He also describes the limits of research itself. Most human cancers develop slowly over periods as long as 20 years. Laboratory experiments need to work with high dosages of carcinogens over shorter periods of time, which may have very different effects. The need to use animals will always leave questions as to whether results would be the same for humans.

Epidemiological studies on the frequency or spread of diseases among populations have provided important clues. Groups of African and Japanese immigrants who moved to the United States but married within their own communities for generations provided researchers with the opportunity to compare the frequency with which various cancers occur among these ethnic groups in their original countries and in native Americans of European stock.

"What has been learned," Alibaster writes, "is one of the most important facts ever to come out of cancer research: namely that when people migrate to a new country they gradually acquire a pattern of cancer that is characteristic of their new country, mostly as a result of losing their original dietary habits and possibly from being exposed to other factors in the environment." This observation shows that cancer is potentially preventable and is not genetically determined except perhaps through a subtle susceptibility to environmental factors.

Alabaster argues that we should act upon what is known without waiting for absolute proof. "Dietary recommendations, unlike speculative medical treatment, are unlikely to produce more harmful consequences than the dietary anarchy that currently exists." Besides, the risks of not acting are high.

The key to his National Anticancer Diet is balance. Ideally, we should learn the chemical composition of foods and design a diet plan that incorporates the best knowledge to date with occasional updating when more becomes known. Alabaster provides extensive nutritional charts, advice and even sample menus to get the reader started. He uses a flexible and realistic approach: If you are a person who is unable to give up drinking or smoking, he suggests shifts in the composition of your diet that may actually cancel out some of the carcinogenic effects of your bad habits.

Even though the thought of getting cancer frightens nearly everyone, most of us take a curiously passive approach, as if we were powerless to influence our health, Alabaster says. This book is a serious attempt to help us beat the odds.

It is hard reading; you will want to underline or take notes. At times it is aggravatingly redundant; it cries out for better editing. But it is a most informative book. You will finish it and go directly to your grocery store -- either before or after you do a major overhaul of what is in your kitchen.