Amino Acid Assessment Workshop (AAAW)

10th AAAW November 19-20, 2019, Tokyo

On November 19-20, ICAAS organized in Tokyo (Japan) a major scientific workshop (10th Amino Acid Assessment Workshop). We welcomed more than 60 academic experts with an aim to discuss clinical data on safety of three amino acids: histidine, lysine and methionine. In addition, the final session of the Workshop was devoted to emerging science approaches. The Proceedings of the Workshop will be published later this year in J. Nutrition – a major peer-reviewed scientific Journal.
Based on research topics presented during the 10th AAAW, the ICAAS Scientific Advisory Committee proposed the following maximum limits for supplemental amino acids in humans: methionine at app. 3.2 g/day, histidine at 8.0 g/day and lysine at 6.0 g/day. These NOAELs are applicable only to high-purity amino acids and they indicate that there is a ubstantial safety margin for the investigated amino acids.
As ICAAS has indicated in the last decade, the main determinant of safety of ingredients such as amino acids, is their purity and quality.

9th AAAW October 15-16, 2015, Paris

Thu, 2015-10-15 – Fri, 2015-10-16
Paris, FRA
On October 15-16, 2015; ICAAS sponsored the 9th Amino Acid Assessment Workshop (AAAW). Similarly to all previous AAAWs, the 9th installation of the event was constructed and supervised by the ICAAS Scientific Academic Committee, currently made of Profs. Denny Bier (Huston), Luc Conober (Paris), M. Kadowaki (Niigata), Sid Morris (Pittsburgh) and R. Elango (Vancouver).

The event was organized at the “L’Hotel du Collectionneur” (Paris, France) and as many as 76 leading scientists participated. Day 1 morning session was focused on animal and human data relevant to the safety of the semi-essential amino acid arginine. Presentations and discussions were emphasizing the outcome of ICAAS-sponsored research projects and on the use of new data to determine the upper level of the safe intake (UL) of arginine. General discussion indicated that arginine could be added to normal diet, which by itself contains 3-5 grams of arginine, during prolonged time periods (as long as 3 months) at a very high level (30 gram per day) without any noticeable negative effects. Even if a safety factor of “2” was applied, the presented data would still provide a huge safety margin (15 gram of arginine added to normal intake per day). Considering broad uses of this amino acid, the Workshop provided a very important safety “backbone” for the current and future practical applications.

Afternoon session of Day 1 was focused on the essential amino acid tryptophan which is often used in supplements to improve sleep and modulate mood. The reviews of medical and nutritional literature, as well as the summary of the ICAAS-sponsored clinical study supported UL for tryptophan at 5.0 grams per day when added to normal diet which already contains approximately 0.8 grams of tryptophan per day.

Day 2 was dedicated to safety of high doses of essential amino acid leucine in elderly humans. Leucine stimulates muscle protein synthesis, and thus leucine supplementation to normal diet prevents age related muscle atrophy (sarcopenia). Discussion during the 9th AAAW was centered on new clinical work with elderly humans who were studied using the same techniques as previously applied to young adults The comparison revealed that there was minimal age-differences in UL for leucine (all dietary sources summarized) and that the UL for elderly could be established at > 430 mg per kg body weight per day (app. 30 grams per a 70 kg individual).

Considering that due to technological and taste limitations, free amino acids cannot be easily added to foods or dietary supplements at the above doses, the 9th AAAW confirmed a very high technological margin for key semi-essential and essential amino acids and showed that establishing ULs for those substances is not a regulatory priority.

Finally, presentations made during the 9th AAAW as well as a summary of the Workshop similar to this one, will be published in a reputed scientific journal (J. Nutrition) within several months to serve as a reference to regulators and scientists.

8th AAAW November 10-11, 2011, Washington, DC

Thu, 2011-11-10-Fri, 2011-11-11
Washington DC
The 8th International Amino Acid Science Workshop (AAAW) was held at the Ritz-Carlton Hotel Georgetown (Washington, DC, USA) on November 10th and 11th, 2011.
65 industry, academia and government experts from 11 countries attended the meeting.
The purpose of this workshop is to establish a framework for evaluating and predicting the results of various amounts of leucine and tryptophan taken by humans under various conditions. The dialogue between experts in the fields of molecular biology, toxicology, regulation and policy can be continued.
In the morning session on the first day, we co-sponsored the International Life Science Research Foundation (ILSI RF) and focused on the ILSI RF approach aimed at establishing the upper limit of nutrients.
Four speakers explained the latest approach aimed at establishing upper limits for impurities and nutrients.

The safety of leucine and tryptophan was the theme for the other sessions on day 1 and the session on day 2.
Focusing on the results of the research project on these two amino acids supported by ICAAS, we focused on how to use the data to determine the upper limit of the safe intake range.
Lead speakers Dr. Paul Pencharz (Children’s Hospital in Toronto, Canada) and Hissunori Kato (University of Tokyo) presented findings from rodent and human studies on leucine.
In an acute study conducted by Dr. Pencharz’s group, the first-ever direct estimation of the safe range of leucine in humans and taking 550 m / kg-1 • d-1 or> 39 g / day may pose a health risk Raised the recognition.
In the tryptophan session, review of literature was conducted mainly by Dr. Ball (University of Alberta, Canada) and Dr. Fernstrom (University of Pittsburgh, USA).
The speaker suggested that the upper limit of tryptophan catabolism could be a marker for intake, and that increasing intake may increase the risk of side effects.
Data on the upper limit of tryptophan oxidation do not appear to be published yet.
Taking into account various health benefits, a normal dose of 5-8 g / day (70-100 mg / kg / day) gives a maximum of 15 grams / day (200 mg / kg / day for a 70 kg individual) I used tryptophan supplements.
The effective period obtained from the efficacy test is 10-28 days (longer effects may be obtained). There are currently no or no side effects associated with this.
According to a lecture by Dr. Shibata (Shiga Prefectural University), provisional NOAEL (non-toxic dose) ≥ 2,000 mg / kg (body weight) and LOAEL (minimum adverse effect concentration) 5,000 mg / kg (body weight) in rodent experiments The ratio of urinary excretion of anthranilic acid / kynurenic acid is likely to be an index of an alternative tolerance limit (breakpoint) that is optimal for predicting the allowable upper limit intake (UL) of tryptophan. The This research is currently being conducted in human subjects with healthy women as subjects.
The 8th AAAW proceedings will be published in 2012 as an appendix to the Journal of Nutrition.
ICAAS members hope the proceedings will be useful to both researchers and government agencies working on amino acid UL.
ICAAS operates on the premise of providing scientific evidence to support regulatory activities in this area.
Research findings reported during the workshop will materialize this, and discussions regarding the upper limit of allowable amino acid intake will change in the future.

7th AAAW November 2-3, 2007, Tokyo

Wed, 2011-11-02-Thu, 2011-11-03
Organizer: D. Baker, D. Bier, L. Cynober, Y. Hayashi, M. Kadowaki, S. Morris and A. Renwick

Main contents

I. Consideration of upper limit intake of nutrients (joint discussion with ILSI)
II. Animal models and biomarkers for assessing proper and safe intake of glutamic acid (Gln) and proline (Pro)
Proceeding: JN Suppl., Vol.137 No.6S-I (June 2007)

6th AAAW November 6-7, 2006, Budapest (Hungary)

Mon, 2006-11-06-Tue, 2006-11-07
Budapest (Hungary)
Organizer: D. Baker, D. Bier, L. Cynober, Y. Hayashi, M. Kadowaki, S. Morris and A. Renwick

Main contents

Animal models and biomarkers for assessing adequate and safe intake of Lys, Arg and related amino acids. (Animal models and biomarkers for assessing appropriate and safe intake of lysine (Lys), arginine (Arg) and related amino acids)
Proceeding: JN Suppl., Vol.137 No.6S-I (June 2007)

5th AAAW October 24-25, 2005, Los Angeles

Mon, 2005-10-24-Tue, 2005-10-25
Los Angeles
Anim.models & biomarkrs fr assessing of sulfur-containing AAs (SAA): Metabol & function, Adeq.range for SAA & biomarkers for their excess, Effects of SAA excess & suggested UL Animal models and biomarkers for assessing adequate intake: metabolism and function, appropriate SAA intake and overdose biomarkers, effects of SAA overdose and recommended upper limit intake (UL). )
Proceedings: JN Suppl., Vol.136 No.6S-I (June 2006)

4th AAAW October 28-29, 2004, Kobe

Thu, 2004-10-28-Fri, 2004-10-29
Organizer: D. Baker, D. Bier, L. Cynober, Y. Hayashi, M. Kadowaki and A. Renwick

Animal models and biomarkers for assessing adequate dietary intake of BCAA: Diff. B / w nutr. Vs toxicol. Effects, Biomarkers for nutr. Effects and toxicity, How similar are animals to humans? Animal models and biomarkers for assessing appropriate intake: Differences in the effects of nutrients and toxins. Biomarkers that measure the effects of nutrients and toxins. Similarities between humans and animals.)

Proceedings: JN Suppl., Vol.135 No.6S-I (June 2005)


3rd AAAW October 23-24, 2003, Nice, France

Thu, 2003-10-23-Fri, 2003-10-24
Nice (France)
Organizer: L.Cynober, Y.Hayashi, M.Kadowaki and V.Young

Factors affecting amino acid adequacy and their regulatory impact: Physiological factors, variation among populations, scientific issues associated with risk assessment
(Amino acid sufficiency factors and regulatory impact: physiological factors, variation within populations, scientific issues related to risk assessment)
Proceedings: JN Suppl., Vol.134 No.6S (June 2004)

2nd AAAW October 31-November 1, 2002, Hawaii

Thu, 2002-10-31 – Fri, 2002-11-01
Organizer: L.Cynober, Y.Hayashi, M.Kadowaki and V.Young

Main content

Background and framework of risk assessment, pharmacokinetics, function and metabolism, What can be learned from Genome sciencec
(Risk assessment background and framework, pharmacokinetics, function, metabolism. What can we learn from genomics?)
Proceedings: Journal of Nutrition (JN) Supplement, Vol. 133 No. 6S-I (June 2003) program

1st AAAW July 1-2, 2001, Tokyo

Sun, 2001-07-01
Tokyo, Japan

Organizer: Y.Hayashi and V.Young

Main content

Review of AA science status review of, Function, Untoward consequences of abnormal intake, Evaluation of desirable & undesirable intake.
(Study of the scientific status of amino acids: function, unexpected effects of abnormal intake, evaluation of desirable / undesirable intake).
Proceedings: ILSI. 2001; 68: 87-92. (Japanese)