Contending that research has shown attention deficit/hyperactivity disorder (ADHD) can be triggered in some children by food dyes and certain foods, the Center for Science in the Public Interest (CSPI) has urged the U.S. Department of Health and Human Services to encourage parents and doctors to consider diet changes before treating children with stimulant drugs.

CSPI reported that 17 of 23 controlled studies found that diet--and most especially the use of artificial colors--had adverse effects on some children's behavior. The percentage of children who showed an effect, and the degree of that effect, varied greatly among the studies.

The group, along with a number of doctors and researchers active in the field, also urged the government to initiate new research into the possible dietary causes of ADHD, and to consider banning synthetic dyes in food products widely used by children.

"People need to keep in mind that stimulant drugs have side effects for children," said Michael F. Jacobson, executive director of CSPI. "With that in mind, we think it is definitely worth giving a modified diet a try before moving on to stimulant drugs."

Between 3 and 5 percent of school-age children are believed to suffer from ADHD, which results in inappropriate levels of attention, activity, distractibility and impulse control in children.

A National Institutes of Health (NIH) consensus meeting on ADHD last year concluded that stimulants such as Ritalin are effective in alleviating symptoms of ADHD. Regarding the safety of those stimulants, the group wrote: "Although little information exists concerning the long-term effects of psychostimulants, there is no conclusive evidence that careful therapeutic use is harmful."

Jacobson, however, said that a study in rats has found a link between high doses of Ritalin and liver tumors.

The consensus statement reported that evidence regarding the effects of diet on ADHD is "uneven," but also said that some of the diets "showed intriguing results suggesting the need for future research." However, that diet research is not mentioned in the consensus recommendation for ADHD research.

The CSPI report asks NIH to sponsor a new consensus conference on diet and behavior to "provide a full and fair review of studies on diet and ADHD."

Jacobson said the easiest dietary change to make for children with ADHD is to avoid candy, pastries and soda, which all contain food dyes.

--Marc Kaufman



An experimental vaccine against prostate cancer, now under development by researchers at Johns Hopkins Medical Institutions, successfully boosted the immune system in men whose disease had spread throughout their bodies.

Reporting in the current issue of the journal Cancer Research, the Hopkins team reported that the vaccine revved up the immune system in eight patients under treatment for advanced prostate cancer.

"This is a surprising finding and it is very encouraging," said Michael Hamilton, head of the clinical investigation section at the National Cancer Institute, which co-sponsored the study. "It will need to be documented by other trials, but if it turns out to be effective, vaccination would be an ideal way to go with most prostate tumors."

An estimated 179,300 men will be diagnosed this year with prostate cancer, and 37,000 will die, according to the American Cancer Society.

Detected early, prostate cancer can be effectively treated by surgical removal of the prostate, a gland located at the base of the bladder. But many men who undergo seemingly successful surgery still experience cancer recurrence because a few cancer cells escape and spread the disease.

Doctors regularly monitor blood levels of prostate specific antigen (PSA) after surgery to look for recurrences. Men whose PSA levels continue to rise after surgery are at increased risk for spread of their disease. But it can take months to detect these new tumors. Radiation and hormone therapy can be used to treat advanced disease, but these measures are generally reserved until the new tumors are detected.

To help thwart the spread, doctors are searching for new adjuvant therapies that could be given before the new tumors have gained a foothold in the body.

In the Hopkins study, researchers led by William G. Nelson and Jonathan Simons took cancer cells from eight men who had undergone prostate cancer surgery and whose disease was believed to have spread. They inserted into the men's cancer cells a gene known as GM-CSF that helps activate the immune system, prompting it to recognize tumor cells.

The laboratory-grown cancer cells were then irradiated to prevent them from growing any further and this personalized vaccine was injected into each patient's thigh.

Four weeks after vaccination, the researchers found that the immune systems of all eight participants had been boosted by the treatment. B cells--a type of white blood cell--began producing antibodies against the prostate cancer cells. T cells, another type of white blood cell, began attacking the prostate tumor cells.

"We were astounded to find that every part of the immune system was alerted and turned on," said Simons.

This new vaccine joins a small number of other experimental vaccines for prostate cancer now under study at the National Cancer Institute and elsewhere throughout the country.

The fact that the study produced strong immune responses "is very satisfying," said NCI's Hamilton, who is also developing an experimental prostate cancer vaccine. "It indicates that this is a step in the right direction."

--Sally Squires