A randomized, double-blind, placebo-controlled clinical trial investigated TA-65® in 500 healthy women and men aged 45 to 75 years. The focus was on whether nine months of supplementation would lead to observable changes in so-called immunosenescent CD8⁺CD28⁻ T-cells. LIDSEN Publishing
This T-cell population is studied in the context of immune aging. However, a change in their numbers is not automatically synonymous with a proven improvement in general immune defense or protection against diseases.
How was the study designed?
The study was designed as a randomized, double-blind, placebo-controlled parallel-group study. A total of 500 healthy adults aged 45 to 75 years participated. They were divided into five groups of 100 people each: placebo and four different TA-65® dosages. The supplement was taken for nine months. LIDSEN Publishing
The primary investigation was the change in the number of CD8⁺CD28⁻ T-cells, which were used as a marker for immunosenescence. Blood samples were analyzed at the beginning and after nine months. In addition, the CMV status of the participants was recorded.
What results were observed?
In the intention-to-treat analysis including all 500 randomized participants, a decrease in CD8⁺CD28⁻ T-cells was observed for the combined TA-65® groups. An overall statistical multilevel analysis showed a significant difference compared to placebo. However, the results of the individual dosage groups were not uniformly pronounced. LIDSEN Publishing
In the per-protocol analysis with 424 participants, the number of these T-cells in the TA-65® groups decreased by an average of about 13%. In the placebo group, by contrast, no statistically significant change was observed. LIDSEN Publishing
The study also showed that CMV-positive individuals had significantly more CD8⁺CD28⁻ T-cells at the start of the study than CMV-negative individuals. This underscores that, in addition to age, chronic infections such as CMV can be associated with this cell population. LIDSEN Publishing
It is important to note: A decrease in CD8⁺CD28⁻ T-cells is a biological metric for immunosenescence. It cannot be automatically inferred from this that TA-65® improves general immune defense or reduces the risk of infections or other diseases.
How should these results be interpreted?
The study provides controlled clinical data on TA-65® and a marker of immunosenescence. The randomized, double-blind, and placebo-controlled study design, combined with a comparatively large number of participants, is a positive aspect.
At the same time, the results refer to a specific immune cell marker. Whether the observed changes are associated with a concrete health benefit cannot be derived from this.
Further studies would be required to clarify the clinical significance of changes in CD8⁺CD28⁻ T-cells and whether these result in long-term effects on immune function or health.
Further information on the clinical data regarding TA-65® can be found in our article “TA-65®: Current studies on telomere length and safety”.
Original publication
The complete study and further details on methodology and results can be found in the original publication.
