( CNN ) -- A Food and Drug Administration advisory committee that has been weighing evidence on whether dye additives in food affect behavior in children will make its recommendation Thursday . The panel will first listen to testimony from the public and the industry . It spent Wednesday listening to testimony from doctors and scientists who contend that studies , although small in many cases , do show that some kids begin to show signs of hyperactivity once they are exposed to certain dye mixtures . The question is whether the FDA committee will urge the agency to strengthen its regulation of the ingredients ? Although the committee only makes recommendations to the FDA , the agency usually follows those recommendations . According to the experts who testified , European companies already are dropping dyes including Blue # 1 , Yellow # 5 , Green # 3 and others and substituting natural dyes for them . But the United States still allows artificial dyes , mostly for aesthetic reasons , not for taste . `` Why are these dyes in these foods anyway ? '' asked Michael Jacobsen , executive director of the Center for Science and the Public Interest , a watchdog group on nutrition and food safety . `` I would push for having them taken out completely . But if that ca n't be done , why not warn the public and parents that these dyes could have some effects ? '' The idea that dyes in food causes attention deficit hyperactivity disorder , or ADHD , was first noted in `` Why Your Child is Hyperactive , '' a book written by Dr. Benjamin Feingold in 1975 . The eating style described in the book became known as the Feingold Diet . He found if one eliminated artificial food dyes and additives in American diets , cases of hyperactivity in children would decline . But reviews of the data found that the correlation between dyes and hyperactivity were inconsistent . Although numerous data have been collected on food dyes and hyperactivity in kids over the past decade , critics say the design of the studies has been weak . They note many of the studies were performed on small groups -- many involved no more than 25 children . They also noted that much of the observation data ( how the child acted ) was reported by parents and not by clinicians . And they pointed out that most of the dyes tested were combined into a dye mixture and not tested individually . The most recent studies to bring food dyes and ADHD back to the public eye was a 2007 project conducted by researchers at the University of Southampton in the United Kingdom . It showed that artificial food dyes along with sodium benzoate ( a white crystalline salt used as a food preservative ) increased ADHD symptoms in both hyperactive and non-hyperactive children . That study was followed up by another paper in 2010 by the same researchers who looked at the connection between food dyes , ADHD and histamine , a chemical that 's produced in the brain when the body is having an allergic reaction . `` We found mixtures of certain artificial colors together with sodium benzoate preservative in the diet increased the average level of hyperactivity in 3 and 8/9 year old children in the general population , '' Dr. Jim Stevenson , a professor at the School of Psychology at the University of Southampton , and lead author of the study , testified Wednesday . `` We found mixtures of certain artificial colors together with sodium benzoate preservative in the diet increased the average level of hyperactivity in 3 and 8/9 year old children in the general population . '' Yet , it was noted that when the Southampton data were unveiled to the European Food Standards Authority , a European version of the FDA , the EFSA found the evidence weak . But some groups in the United States say the findings are another reason that dyes should go . A recent report issued by CSPI looked at data from a number of studies related to artificial food dyes . Jacobsen argued to the board Wednesday that artificial food dyes are not safe for humans and can be connected to numerous health problems , including ADHD allergies , even cancer . `` The average child consumes approximately 121 milligrams of artificial dyes a day , '' Jacobsen asserted . `` That 's a lot . And dye in food is used twice as much as it was in the 1970s . These are noted scientific effects . There are other factors that could affect child behavior , but if we can take out food dyes as a factor , why not ? ''
The FDA usually follows through with panel 's recommendation . Testimony : Some studies show some kids show signs of hyperactivity . Testimony : European companies are dropping dyes . The United States still allows them .