By Louis J. Elsas, II, M.D.
Director, Division of Medical Genetics Professor of Pediatrics
Emory University
And Others

Posted: 25 April 2004


S. Hrg. 100-567


(pages 360 through 369 of S. Hrg. 100-567)

Senator Metzenbaum: Dr. Elsas, since Senator Hatch saw fit to go into the funding question, I will ask you, are your studies funded by industry?

Dr. Elsas: No, sir. I had a research grant three years ago, for three years, from the March of Dimes, to study the effects of phenylalanine on human brain function. When the political issue got to aspartame, the society decided not to refund that. So all of the funding that is going on now - and the reason it is so slow has been through my own division's efforts, personal funds, and university-based fund.

Senator Metzenbaum: What do you think of our present system for funding scientific research?

Dr. Elsas: I think the NIH is superb, I think there is a lot of concern about how industry and the FDA interact, where industry is made responsible for developing the data to support its own contentions. There is not a broad enough scientific base, such as an RFA, as we can it at NIH - research funds available - requesting input from the whole scientific community, stating that funds are in an unbiased approach - what the questions are which we need to ask? That is the problem here today. The questions about phenylalanine effects on human brain function have not been asked. So we have spent millions of dollars through our current system on mostly irrelevant experiments without approaching those particular questions.

Senator Metzenbaum: What about the advertising campaign that NutraSweet puts on, and are you concerned about that?

Dr. Elsas: Yes, sir.

Senator Metzenbaum: In what way?

Dr. Elsas: I am mostly concerned that it gives the false impression that NutraSweet is good for you, that it is nature's best, and that it might even be good for children to take. A lot of the ads recently have shown children with the little ying and yang NutraSweet thing on it, making it sound like you should go with your mommy to the grocery store and look for that, and be sure that you buy that because it is real sweet and good.

Senator Metzenbaum: Can you tell the Committee about your own experiences with the International Life Sciences Institute?

Dr. Elsas: Yes, sir. It was not good.

Senator Metzenbaum: Who is that group, can you tell us?

Dr. Elsa: Well, Dr. Dews is right here; he can probably give you more personal information about it, because I have never gotten any feedback from them. But I was asked after issuing concerns both privately and then publicly on "Nightline" to give them a specific protocol for how I would approach these concerns. I did this. I wrote it up completely in a research grant format; submitted it through ILSI for their review, and basically, got a few phone calls from Dr. Dews over a prolonged period of time, stating that they had problems, but without ever a written peer review of criticism.

So I basically never got funded; that is the bottom line. And the ideas are now reappearing three years later in other places funded by industry.

Senator Metzenbaum: ILSI is pretty much the coordinating group for funding in the food and beverage industry, including pops, carbonated drinks, NutraSweet itself; is that correct?

Dr. Elsas: As far as I know, that is correct, sir. I am not an expert on ILSI; I have repressed that experience.

Senator Metzenbaum: It is my understanding that Dr. Pardridge has to catch a plane, so I am going to pass on to him. But I appreciate your testimony, Dr. Elsas, and I am only sorry Senator Hatch was not here to hear you comment on the fact that - at least, the inference; it is not a fact - that if the information or the research is not going to be supportive of their position, that sometimes one does not get supported by organizations such as ILSI, NutraSweet and others.

Do you think that general conclusion of mine might be inappropriate, or appropriate?

Dr. Elsas: Sir, I think that is very cogent and appropriate.

Senator Metzenbaum: Thank you very much. Would you agree with that, Dr. Wurtman?

Dr. Wurtman: Yes, sir.

Senator Metzenbaum: Thank you. Dr. Pardridge, we are happy to hear from you, sir.

Dr. Pardridge: Thank you, Senator, and thank you for having me.

I am a Professor of Medicine at the University of California, a practicing endocrinologist, and I have been doing neuroscience research on the blood-brain barrier transport of phenylalanine and other substances since 1970.

I believe in the discussion this morning, there are three key scientific food policy questions that have really not been properly illuminated.

The first question is the dosage problem. We are led to believe by the FDA this morning that the typical consumer will have 2 to 4 milligrams per kilogram of aspartame per day; that the 99th percentile intake is 34 milligrams per kilograms per day; and that the advisable daily intake or ADI is 50 milligrams per kilogram per day.

Now, the layperson sitting in the audience is really in no position to analyze these esoteric numbers. But if we put it in a different context and recognize that 50 milligrams per kilogram per day is equal to 5 servings of NutraSweet per 50-pound body weight, we are at great risk for overconsumption of NutraSweet.

All one has to do in this room is look up at that chart and ask yourself if a 50-pound or 60-pound 7 year-old is going to consumer 5 or 6 servings of that per day. If they are, then they have consumer 50 milligrams per kilogram per day, of the advisable daily intake.

Now, an 11-year study in the literature has already shown this, that the average 7-to-12-year old, when made freely available to products like that, consumes 5 servings per 50-pound body weight per day, and up to 77 milligrams per day.

Senator Metzenbaum: That is the average?

Dr. Pardridge: The average in children is the ADI - 5 servings per 50- pound body weight. Ask yourself: Would an average child have 5 servings? I think the answer is yes.

Another study by Porikos in obese subjects showed that the average intake was 20 milligrams per kilogram per day, or 2 servings per 50-pound body weight, and that obese adults consume up to 36 milligrams per kilogram per day, even in the face of that high body weight.

Now, if you accept the premise of the first question, that some individuals and in fact many children consume near the advisable daily intake of 50 milligrams per kilogram per day, then you must ask yourself what level of increase in blood phenylalanine will be concomitant with that ingestion of NutraSweet. And the answer is that your blood phenylalanine will rise three-to four-fold. That is not 10 percent or 20 percent. That is 300 to 400 percent. And this study has been done by Drs. Stenink and Filer, which was funded by the industry.

If you now accept that many individuals, particularly children, consume 50 milligrams per kilogram per day, or 5 servings per 50-pound body weight per day, and that they enjoy or a four-fold increase in their blood phenylalanine, the third question that must now be addressed is, are there any untoward effects on the human brain, that are associated with a four- fold increase in phenylalanine, bearing in mind that this molecule is a known neurotoxin?

And three studies come to mind. One study shows that when blood phenylalanine in pregnant mothers is increased five-fold, there is a 10- point drop in the I.Q. of the baby born of that mother.

Senator Metzenbaum: Of I.Q. All right.

Dr. Pardridge: A second study shows that if you measure choice reaction time, a test of higher cognitive function in humans, that when their bloom phenylalanine is increased six-fold, there is a 10 percent shift in your ability to make a key decision before a video screen.

And a more recent study by Dr. Elsas has shown that there are quantitative changes in the human electroencephalogram when the blood phenylalanine is raised three-fold - something that clearly will happen in children who consume near 5 servings per 50-pound body weight.

So if I may summarize, phenylalanine, is a known neurotoxin, and the food industry added nearly 8,000 tons of aspartame to the food supply in 1986, which amounts to approximately 8 million pounds of phenylalanine added to our food supply in a single year.

The consumption of aspartame has increased exponentially since its introduction in 1981. The 1986 consumption of aspartame in the United States was equal to nearly 22 percent of the 1986 consumption of refined sugar when one allows for a 200-fold increase in sweetener potency of aspartame relative to sugar.

With the enormous selective infusion of phenylalanine into the food supply, the key questions before the United States Congress and other scientific and medical organizations are whether selective increases in the blood phenylalanine level on the order of 200 micromolar or four- fold above normal, are to be expected with liberal intake of aspartame, and whether blood phenylalanine increases of this magnitude have untoward effects on the human brain.