After he finished his traditional medical training, Dr. William G. Crook went back to his hometown of Jackson, Tennessee, and opened his pediatric medical office in 1949.

Soft drinks provide about 1/3 of our added sugar.

"I knew nothing then about the things that excite me today," he said. "I knew nothing about sugar at that time, and I ate as many Baby Ruth candy bars and drank as many Cokes as anybody else. I really didn't know anything about nutrition."

Over the years, Crook said, he learned about food allergies from his practice and from people interested in nutrition, like Nathan Pritikin, who was the first to advocate a very low-fat diet. Crook began eating a better diet of fruits, vegetables and whole grains, he said.

And he began to see patients with nutritional problems. "I am 83, and one of the advantages of being as old as I am is that I've seen a whole generation of kids grow up. In the '50s I didn't see kids who today are called ADHD (attention deficit hyperactivity disorder). By the mid-'60s, I began to see more and more of these children."

In the early 1970s, he was seeing a lot of children with behavior and learning problems. When he put them on a diet for one week that excluded sugar and seven other foods, they got better.

"So I kept a record of every new child with ADHD that I saw for five years," he said. "I saw 182 of these children with behavior and learning problems where they avoided those foods and then added them back one at a time. I also asked parents what dietary ingredient ever disturbed your child's behavior, made him hyperactive and what foods were the most common offenders. Sugar was the No. 1 thing they identified."

Three out of four children improved significantly when their diets were changed. They were sensitive to an average of three dietary ingredients, and the main ones, he said, are sugar, food coloring and milk.

He published his findings as "Can what a child eats make him dull, stupid, or hyperactive?" in the May 1980 issue of the Journal of Learning Disability (pages 281-286. Subsequently, he has written widely about effects of sugar that he has seen in his clinical practice.

Like some other medical doctors, Crook has serious concerns about sugar based on what he has seen in his practice. In summary, he said, "Simple sugars are empty calorie foods, and the excess ingestion of them plays an important role in making a lot of people unhealthy."

Differences of opinion
Not everybody agrees. In particular, the Sugar Association in Washington, D.C., takes issue with Crook on sugar's role in attention deficit hyperactivity disorder.

That excess sugar causes ADHD is "a pretty widely held misperception," said Dick Elder, the association's director of public relations. "But it's absolutely wrong. The science has been pretty clear on that for at least five to six years."

What he is referring to is a study of the studies—a meta-analysis—of "The Effect of Sugar on Behavior or Cognition in Children" by Dr. Mark Wolraich of Vanderbilt University in Nashville, Tennessee. His study is in The Journal of the American Medical Association, November 22/29, 1995 (pages 1617-1621).

After reviewing 23 placebo-controlled, double-blind studies in which children ate a known amount of sugar, Wolraich, a medical doctor, concluded that "sugar does not affect the behavior or cognitive performance of children. The strong belief of parents may be due to expectancy and common association."

Still, "there are not enough studies to reach a definitive conclusion," Wolraich wrote. His final recommendation is for more studies to see if sugar can affect certain groups of children or to see if sugar might have a small effect.

The disturbing trend—sugar consumption is increasing every year
There may be no agreement about the effects of sugar, if any, on ADHD or just about any other disease, but there's no disputing the tremendous increase in U.S. sugar consumption.

Wolraich points out that the low nutritive value of refined sugar consumption has been a concern in the United States since the Civil War. Questions about possible adverse effects on behavior were raised as early as 1922.

But we ate a lot less sugar in those days. The U.S. Department of Agriculture has been tracking American sugar consumption since 1909. In that year, Americans consumed 83.4 pounds of caloric sweeteners per person.

At that time, all caloric sweeteners came from cane and beets, honey and edible syrups including sorghum, maple and sugar cane syrup, edible molasses, edible refiner's syrup and glucose and dextrose from corn. It wasn't until 1967 that high fructose corn syrup became available.

Since 1985, corn sweeteners—mostly HFCS but also including glucose and dextrose—have provided more than half of all the caloric sweeteners that Americans consume. This is largely because HFCS is less expensive and therefore the sweetener of choice for the soft drink industry.

It was also in 1985 that U.S. consumption of caloric sweeteners took off after holding steady for at least the previous 15 years. Americans consumed 128.8 pounds of sugar per person in 1985. Except for a drop in 1986, it increased in every year since then. In 1999, consumption reached 158.4 pounds per person.

These data are valuable and accurate in determining trends in sugar consumption, but they include sugar that was discarded or went into other uses, such as pet food. The USDA's Economic Research Service thinks that about 37 percent of the sugar consumed disappears into other uses, said Judy Putnam, an ERS economist. That would mean the typical American ate 99.8 pounds of caloric sweeteners last year, or about 34 teaspoons per day. This method provides an estimate of the most we could be eating.

Another part of the USDA, the Agricultural Research Service, asked a representative sample of 15,016 people 2 years old and over to report how much they eat in a day. This 1994-96 Continuing Survey of Food Intakes by Individuals found that Americans were averaging 20 teaspoons of added sugars each day. That figure is probably low because of underreporting, said ARS food scientist Dr. Shanty Bowman, and provides an estimate of the least that we could be eating.

Bottom line? Americans are eating an average of between 20 and 34 teaspoons of added sugar per day.

Where's the sugar, and who eats the most?
About one-third of our added sugars come from non-diet soft drinks, Bowman said. The next biggest part comes from baked products, contributing 13 percent.

Children have the highest intakes of added sugars, according to the survey results (the estimate that would be on the low side). Teen-age boys (age 12-19) ate the most, 34.2 teaspoons per day. Among females, girls in that age group ate the most added sugar, 23.5 teaspoons per day.

Bowman divided the people in the survey into three groups based on the percentage of calories they consumed from added sugars. Her analysis, "Diets of Individuals Based on Energy Intakes From Added Sugars" in Family Economics and Nutrition Review, 1999, No. 2 (pages 31-38), shows that the more calories from added sugars that people ate, the greater the number of total calories they took in, but the poorer their intake of essential nutrients, including vitamins A, E and C, all the B vitamins, magnesium, iron, zinc and calcium. Those who ate the most added sugars also had the lowest intake of grains, fruits, vegetables, protein and dairy products, which most people think are critical to growth and health.

How much sugar is OK?
The USDA's Dietary Guidelines for Americans, 2000, recommends only to "choose sensibly to limit your intake of beverages and foods that are high in added sugars."

Sugar Association spokesman Elder said, "We had a positive influence on the dietary guidelines." A panel of experts initially recommended that Americans reduce their sugar intake. But after receiving public comment, the sugar guideline of the final report stayed close to the wording of the earlier dietary guidelines. In 1980 and 1985, the report said to "avoid too much sugar." In 1990, it said to "use sugars only in moderation." And in 1995, it said to "choose a diet moderate in sugars."

The government's Food Guide Pyramid is the closest thing to a recommendation that we have. It says that people eating 1,600 calories per day should "try to limit" their added sugars to an average of 6 teaspoons per day. Those of us who eat 2,200 calories per day should limit added sugars to 12 teaspoons, and those eating 2,800 calories should stay at or below 18 teaspoons.

That's a lot less than the typical American eats. Some people think that this high sugar consumption is causing a lot of our health problems.

Children and sugar
In addition to Crook, many other doctors think the growing incidence of attention deficit hyperactivity disorder is related to sugar consumption. Dr. Benjamin Feingold, who died in 1982, was one of the first pediatricians to become concerned about hyperactivity. He specialized in child and adult allergy and taught pediatrics at Northwestern University Medical School and later became chief of pediatrics at Cedars of Lebanon Hospital in Los Angeles.

In the mid-1970s, Feingold generated a firestorm of controversy when he maintained that artificial colorings and flavorings and certain natural chemicals (salicylates in apricots, berries, tomatoes and other foods) could trigger ADHD. The Feingold Association of the United States carried on in his name. The Feingold diet eliminates several foods—but not sugar, except for sugar made from corn.

"We do tell people to cut down drastically on sugar, said Lynn Murphy, the association's development director and director of communications. "Keep a diet diary and note that if the child has major problems after a holiday. If everything else in the diet has been OK, it might just have been the sugar."

But according to Murphy, a certain subgroup of kids who have been diagnosed with ADHD truly do have a problem with sugar. "Typically, those are the kids who are really difficult to get them to relax at night and go to sleep, and it is hard to get them up in the morning. It's about one-fifth of those kids with ADHD that we see, so there is something definitely going on with sugar."

But even kids who are not especially sensitive to sugar can demonstrate something that the association calls the "Halloween Hangover," Murphy saids. "If your child's behavior changes a lot after Halloween, it could very well be the overabundance of candy that he or she is eating. Then it is up to the parents to find out if it is the artificial ingredients in the candy or the sugar itself. This is something that teachers have seen for a long time. Teachers notice that the day or two after Halloween, kids have major problems paying attention, and they are kind of grouchy. They go to extremes, becoming either they very hyper or very blah."

While recognizing the trailblazing role that Feingold played, Dr. Doris Rapp, an environmental medical specialist and pediatric allergist in Scottsdale, Ariz., says he "opened up the doorway because he recognized that artificial flavors and colors could cause trouble." But Rapp doesn't think the problem was the salicylates he singled out.

"Later, it was found that milk or sugar could make some children hyperactive," she said. Rapp is the author of Is This Your Child? and Is This Your Child's World?, two comprehensive books for identifying substances that cause illness and behavioral changes in children and for evaluating treatment options.

"The sugar industry says that sugar doesn't cause any problems," she said, "but all you have to do is to talk to any teacher after Halloween and Valentine's Day and Christmas, and ask them, �How are the children?' The day after Halloween, they can't even teach because everybody is so wound up."

You can have food addictions like alcohol addiction, she said. And some children are addicted to sugar. I tell parents to take their child totally off of sugar for five days. For the first two days, they will be a terror because they are going through withdrawal. But after five to seven days off of sugar, they will be wonderful."

Like Rapp, Dr. Leo Galland focuses on children who crave sweets. He is an internist who specializes in nutritional medicine in private practice in New York City and is director of the Foundation for Integrated Medicine, which does educational work. He is the author of Power Healing and Superimmunity for Kids.

About 70 percent of children who crave sweets have much more control over their behavior when their food is low in added sugar, he said. "My first line of advice to parents is to keep their children away from sugary cereals, pancakes or waffles with syrup, soft drinks, candy, cakes, cookies, doughnuts, ice cream, frozen yogurt and chocolate. Every ounce of reduction helps. Sugar alone does not cause hyperactivity, but it does reduce the nutritional quality of the diet and may aggravate other food intolerances."

Most of the studies of children, like those analyzed by Wolraich, did not show that kids became hyperactive when fed pure sucrose or pure glucose, Galland said. But he thinks that is a problem with the study design.

"Children are always having sugar with something else," he said. "It has been very well established in several well-done studies that a percentage of children with ADHD are food sensitive."

When there is a high concentration of sugar in the intestine, it increases the permeability of the intestines so that substances are absorbed that are ordinarily excluded, he said. "For example, if you have someone who has a low-grade allergy to wheat, they eat wheat and they may not respond very strongly to it. But if they then consume a combination of wheat and sugar, they are going to absorb more of the wheat antigen, so they will respond to it more strongly."

Even the source of the sugar mattered, according to a study of overactive children in England. A study by J. Egger, et al, "Controlled trial of oligoantigenic treatment in the hyperkinetic syndrome," Lancet, March 9, 1985 (pages 540-545), is what Galland calls "the gold standard."

Of the 76 children in the study, 62 improved when Egger limited their diet to a small number of foods that are unlikely to provoke intolerance. Sugar and 47 other foods were incriminated.

"There were children who were sensitive to cane sugar and other children who were sensitive to beet sugar," Galland said of the study. "Corn sugar was not in that study, and there are people who are sensitive to corn sugar who may not react to cane sugar. Corn sugar is used a lot more now than then and more in this country than in England, where he did his work. So it could be worse now."

Can sugar make you fat?
But what about obesity? Doesn't eating too much sugar cause you to get fat?

The rise in U.S. sugar consumption paralleled by dramatic increases in obesity does seem suspicious. "And most researchers in this area would agree that that is to some extent responsible for the increase in obesity," Galland said.

The prevalence of obesity across all age groups increased from 12.0 percent in 1991 to 17.9 percent in 1998, according to Ali H. Mokdad and his associates at the Centers for Disease Control and Prevention in Atlanta, "The Spread of the Obesity Epidemic in the United States, 1991-1998, Journal of the American Medical Association, October 27, 1999 (pages 1519-1522). The age group with the biggest increase, a 70 percent jump in obesity over eight years, was the 18- to 29-year-olds.

Elder believes that "we are probably going to see another round of scientific inquiry, given the current sparks flying around the subject of obesity, but the science today does not show that eating foods and beverages containing sugars causes obesity." It is calories from any source and lack of physical activity that causes obesity, he said.

WHO's and the Food and Agricultural Organization's carbohydrate experts concluded that there is no direct evidence implicating either sugars or starches in promoting obesity. The amount you eat remains key. "It is important to reiterate that excess energy in any form will promote body fat accumulation," the experts concluded.

Although it appears from the available evidence that sugar might not be different from other sources of calories in promoting obesity, it also is clear from the statistics that reducing sugar intake is one of the most direct ways to reduce total calories. Considering that average intake of added sugars is two to three times what the USDA recommends and that diets high in added sugars tend to be low in important nutrients, hardly anyone disagrees with the recommendation to cut down on added sugars as part of a strategy to combat obesity.

Diabetes, a parallel epidemic
Like sugar consumption and obesity, diabetes in America is growing at an alarming rate. Still, there is no proof that sugar consumption is the direct cause here either. Indeed, the story is much more complex.

It's not sugar that causes diabetes, but rather "a combination of genetic and environmental factors. However, being overweight does increase your risk of developing Type 2 diabetes, so if you have a history of diabetes in your family, a healthy diet and regular exercise are recommended to control your weight," according to the Diabetes UK Web site.

But even if sugar doesn't cause diabetes, don't people who have the disease have to avoid it? In fact, the American Diabetes Association stopped recommending that people with diabetes avoid sugar in May 1994. The association based its decision on a technical review led by Marion Franz, a registered dietitian and certified diabetes educator.

"I haven't seen one shred of evidence that sugar causes diabetes," she said. "The only way it could possibly be related would be if people consumed excessive amounts of sugar, contributing to obesity, and then it would be the obesity, not the sugar. Obesity and diabetes are associated, but it is not proven that obesity causes diabetes."

On the other hand, some experts believe that diets that are high in overall carbohydrates, including sugar, contribute to both diabetes and obesity by increasing the body's production of insulin. According to Dr. Diana Schwarzbein, an endocrinologist and diabetes specialist and author of The Schwarzbein Principle, even so-called "heart healthy" diets contribute to diabetes. "That is an absolute yes. If you take out fat, you are going to be left with too many carbohydrates. That will increase insulin, and anything that increases insulin over a long period of time is going to give you a higher risk for diabetes."

Yeast infections and Candida-related complex
When most people think of yeast, they think of baker's yeast or brewer's yeast. However, it is a different kind of yeast, Candida albicans, a normally benign microorganism in the body, that causes yeast infections. "When you take antibiotics and a high-sugar diet, it multiplies," Crook said. "Simple sugars encourage multiplication of this yeast in the digestive tract."

Two studies showed that women with recurrent yeast vaginitis had higher sugar intakes than women with other types of vaginitis, Galland said. "Decreasing the sugar intake decreased the frequency of yeast infections."

Some people believe that an overgrowth of Candida yeast in the intestines can contribute to a complex pattern of symptoms that can include fatigue, depression, muscle pains, food or environmental sensitivities, hormonal disturbances and cravings for sugar or yeasted foods. Crook and other clinicians who are familiar with the pattern call it "Candida-related complex" and recommend low-sugar diets, yogurt or acidophilus supplements to replenish the intestines' friendly bacteria, and antifungal medications to help control the yeast. Crook's books include The Yeast Connection Handbook.

While some practitioners are convinced that Candida-related complex is a factor for many of their patients, others remain skeptical.

Tooth decay and sugar—the non-controversy
While the effect of sugar on ADHD is controversial, the one health concern of sugar consumption that just about everyone agrees on is dental caries, or tooth decay. The main proven effect of sugar is on increasing dental caries, Galland said.

"That, of course, isn't going up," he said. "But that is largely because of other measures, such as fluoridation and better dental hygiene."

Even the Sugar Association's Elder agrees that sugar is a factor in tooth decay. "But that sugar can come from any sugar or starch," he said. "So a potato or another starch can kick off the same process as a candy bar."

Sugar and your family's diet
If you or a family member has one of these conditions that may be caused or exacerbated by eating a lot of sugar, consider cutting way back. Should you cut out all sugar? It's in so many foods, you probably couldn't even if you tried.

For even those of us in the best of health, remember that the average American is consuming much more sugar than the USDA's recommendations. What can you do to cut back on your sugar intake?

This article originally appeared on NutriNews.com on October 30, 2000.

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