Condition category
Not Applicable
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Alzheimer's disease is the most common form of dementia. It is associated with the accumulation of amyloid β-peptide (Aβ) in the brain. Besides the brain, several changes have been observed in the blood of dementia patients, such as distortions and rapid aging of red blood cells, and an abnormal accumulation of phospholipid hydroperoxides (PLOOH), a sign of membrane oxidative injury. Aβ has been found to cause oxidative injury to red blood cells, impairing their function (i.e., oxygen delivery to the brain), which may contribute to Alzheimer's disease. However, no extensive study has been undertaken of the presence and distribution of Aβ in red blood cells. The aim of this study is to assess the distribution of Aβ in the red blood cells of young and older people.

Who can participate?
People aged 20-69 with total cholesterol level 200-260mg/dL or LDL-cholesterol level 120-180mg/dL

What does the study involve?
The red blood cells Aβ levels are compared between young and older people and also compared to plasma Aβ levels. In addition, a study was previously conducted to find out whether nutritional supplementation with the antioxidant astaxanthin affects red blood cell PLOOH. Red blood cells obtained from this study also have their Aβ levels measured in order to look to the relationship between red blood cell Aβ and antioxidants/oxidants.

What are the possible benefits and risks of participating?
All participants are likely to benefit from general advice. Those with decreasing PLOOH levels have may gain additional benefit, although the effectiveness of this process has not yet been proved. Potential risks include brief pain when drawing blood. This is likely to be similar to the normal muscle ache that people often get and is likely to go away after a couple of minutes.

Where is the study run from?
Shirogane Exe Clinic and Tohoku University (Japan)

June 2010 to September 2010

Who is funding the study?
Yamaha Motor Co., Ltd (Japan)

Who is the main contact?
Associate Professor Kiyotaka Nakagawa

Trial website

Contact information



Primary contact

Prof (Associate) Kiyotaka Nakagawa


Contact details

1-1 Tsutsumidori-Amamiyamachi Aoba-ku Sendai

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Amyloid β levels in human red blood cells: a randomized controlled trial


Study hypothesis

Therapeutic application of astaxanthin as an Aβ-lowering agent in red blood cells (RBCs) could be considered as a possible anti-dementia agent.

Ethics approval

Ethical Committee of TES Holdings,17/05/2010, ref: 2010-04

Study design

Randomized double-blind placebo controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet



Astaxanthin supplementation study


1. Higher astaxanthin content group: Ingesting supplement containing 1mg astaxanthin
2. Lower astaxanthin content group: Ingesting supplement containing 3mg astaxanthin
3. Control group: placebo

Total duration of investigation was 12 weeks

Intervention type



Drug names

Primary outcome measures

1. Biological Antioxidant Potential (BAP) test
2. Determination of Reactive Oxygen Metabolites (d-ROMs) test
Measured at Visit 1: Screening, Visit 2: Week 1, Visit 3: Weeks 4, Visit 4: Weeks 12

Secondary outcome measures

Peroxidized phospholipid measured at Visit 1: Screening, Visit 2: Week 1, Visit 3: Weeks 4, Visit 4: Weeks 12

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Male and female, aged 20-69
2. Blood Test Value: Total Cholesterol: 200-260mg/dL or low density lipoprotein (LDL)-cholesterol: 120-180mg/dL

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. All subjects who are capable to cause serious allergy symptoms to foods and medical drugs
2. They ingest medical drugs or herbal medicines which will affect result of test
3. They continuously ingest foods prepared with astaxanthin during past one month or even today
4. They regularly ingest health foods and beverages which profess similar effects with test foods
5. They drink alcohol more four or more days per week in the past three months
6. They have a history of circulatory disease, nephritis and hepatitis
7. They have digestive disease or have experienced the surgery of the digestive organs (except of surgery of appendicitis)
8. They exceed more than 2.5 of the standard value of Aspartate transaminase (AST), Alanine aminotransferase (ALT ) and gamma-glutamyltranspeptidase (γ-GT)
9. They exceed more than 9.0 ml/g of the uric acid
10. They have serious anemia
11. They participate in other clinical trial with human subjects
12. They are judged by the principal investigator to participate in this clinical trial

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

1-1 Tsutsumidori-Amamiyamachi Aoba-ku Sendai

Sponsor information


Yamaha Motor Co., Ltd (Japan)

Sponsor details

3001-10 Kuno Fukuroi

Sponsor type




Funder type


Funder name

Yamaha Motor Co., Ltd. (Japan)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2012 results in:

Publication citations

  1. Results

    Kiko T, Nakagawa K, Satoh A, Tsuduki T, Furukawa K, Arai H, Miyazawa T, Amyloid β levels in human red blood cells., PLoS ONE, 2012, 7, 11, e49620, doi: 10.1371/journal.pone.0049620.

Additional files

Editorial Notes

30/06/2017: Plain English summary added.