Clinical studies on immune health are ideally designed to include either an immune challenge to the person during the study (in vivo), or a challenge to the person’s immune cells outside the body (ex vivo).
Examples of clinical studies on immune health include:
- Rapid changes in immune status:
- Immune surveillance,
- Immune cell activation status,
- Immune cell function,
- Cytokine production,
- Long term changes to immune health:
- Reduced symptoms for existing immune-related problems (sinus, cold/flu, allergies, acne, cold sores),
- Increased robustness in immune responses (tested ex vivo in lab assays),
- Increased numbers of immune cells in people with immune suppression (such as smokers).
Controlling the Study Environment
The immune system is highly sensitive to stressors, and controlling the study environment is especially important when conducting studies aimed at collecting data on inflammation and immune status. It is also important to control for factors such as circadian cycles and sleep.
Some studies that aim at detection of changes to immune status may need to exclude people with sleep disturbances or nocturnal habits.
In order to minimize potential anxiety and stress, which confounds the data during such a study, study participants should be made familiar with the clinic, staff, and procedures prior to the study. These preparations help increase the ‘signal-to-noise’ ratio and can improve the chances of detecting the physiological change induced by the natural product.
Studies on Acute Effects
A surprising number of natural products trigger physiological changes almost immediately, such as through aroma or physical contact via mucosal membranes, and responses may be measurable within 0.5 – 3 hours of consumption. These responses may also lead to cumulative effects thus indicating both immediate and long-term benefits.
A clinical study on acute effects tracks what happens in the body immediately after consuming a single dose of an immune supportive natural product. It may also track more subtle priming of immune cells. These changes can be measured by taking blood samples and immediately using the immune cells for cell culture to trigger specific immune responses outside the body, thus testing the priming/re-programming that happened within the body after consuming the natural product.
We have a controlled clinic environment for this type of study where the participant sits quietly in a relaxed state with minimal outside stimuli. Blood samples for this type of study need to be processed within 2 hours, and our on-site immunology lab allows us to immediately prepare samples for culturing or flow cytometry.
Studies on Long-Term Effects
Consuming an immune supportive natural product over a longer period of time (4-12 weeks) can lead to measurable changes in immune parameters. However, numerical and functional parameters must be carefully selected, since in most healthy people a fairly constant number of immune cells are maintained over time (homeostasis). Examples of populations with reduced immune function include people who are stressed, smokers, athletes in training, as well as people with cancer and chronic viral illnesses.
In some cases immune studies involve a loading phase (i.e. consuming product daily in the absence of sickness or immune challenge), followed by an immune challenge, such as a vaccine. In other studies, the study design awaits the occurrence of allergies or cold/flu to evaluate an immune response. Alternatively, the immune challenge is performed outside the body, by taking a blood samples from subjects and transferring to the cell culture lab, where the immune cells are exposed to a challenge outside the body (ex vivo), and the response measured in different lab tests.