This study will never recruit. The protocol was renamed and will be resubmitted.

A randomized, double blind placebo-controlled parallel intervention in adults over the age of 50 will be performed. Participants will receive a supplement capsule containing placebo (Crystalline Cellulose) or 500mg of Setria® Glutathione to eat for 120 days. Glutathione is hypothesized to replenish the body's reserves that may be depleted through natural aging process, poor diet, or due to the detoxification process for drugs. The primary end point is the number of healthy days experienced during cold and flu season. Secondary endpoints include cellular and biochemical measures from blood samples taken before and after the study.

The long term goal of this investigation is to understand how food components improve immune function, both in its ability to respond to pathogens and its ability to turn off when the response is no longer needed. The goal of this application is to examine mechanisms by which glutathione improves immune cells after consumption. The central hypothesis is that glutathione improves redox status within the cell, thereby improving cell function and increasing the number of healthy days experienced by the participants.

After obtaining informed consent, human participants will receive 500 mg/day of Setria® Glutathione or placebo for 120 days. Peripheral blood mononuclear cells (PBMC), neutrophils and serum will be obtained from blood draws before and after the 120 days. A daily diary of illness will be kept by each participant and will record any incidence of illness, the number of symptoms per incidence, and the number of days in which symptoms are present. This study is powered on the basis that over 120 days, the glutathione-supplemented group would experience 3% more healthy days compared to the placebo group. The analysis indicated 60 people per group. Timeline should be between mid-January to May because the Center for Disease Control and Prevention indicates that this is the cold and flu season (http://www.cdc.gov/flu/weekly/fluactivity.htm) in the southwest part of the country.

Inclusion Criteria:

• generally healthy
• must have had at least one cold during the previous year
• age 50-75
• must discontinue other dietary supplement use

Exclusion Criteria:

• on arthritis medication
• on hypertension medication
• severe allergies
• compromised immune system
• high cholesterol, heart failure, angina, etc.
• diagnoses of diabetes or metabolic syndrome