Rooted in Tradition: Investigating Birch Root Extract As a Natural Defense against UV Damage

Ultraviolet (UV) radiation from the sun can damage living cells by affecting DNA and slowing normal cell activity. In northern regions like Gods Lake Narrows, UV exposure is intensified by sunlight reflecting off snow and ice, increasing risks such as eye strain and snow blindness—issues long recognized by First Nation communities. These conditions highlight the importance of finding natural, locally available ways to protect cells from UV damage.

One important plant is the birch tree, traditionally used by Indigenous peoples to heal wounds, soothe skin, and reduce inflammation. Ethnobotanical research supports these uses, describing birch as having protective and healing properties. Scientific studies further confirm that birch contains antioxidants, which reduce harmful molecules produced during UV exposure, and natural UV-absorbing compounds that help protect the plant itself from sunlight damage.

Based on this knowledge, the project investigates whether birch root extract can protect living cells from UV damage. Yeast was used as a model organism because it responds to UV stress similarly to other cells and is easy to study. By measuring cell growth (optical density) and carbon dioxide (CO₂) production, the study examines how different concentrations of birch root extract affect cell survival and activity.

Overall, this research connects traditional Indigenous knowledge with modern science, aiming to explore natural and accessible solutions to environmental health challenges in northern communities.

This experiment tested the hypothesis that birch root extract can reduce UV damage in yeast cells, with higher concentrations providing greater protection. The independent variable was the type of solution used during UV exposure, while the dependent variables were cell survival and activity, measured through light transmission (optical density, in lux) and carbon dioxide (CO₂) production (in cm).

To prepare the extracts, dried birch roots were cleaned, cut, and soaked in hot distilled water at three concentrations:

low (5 g)

medium (10 g)

high (15 g)

After steeping for 20 minutes, the mixtures were filtered and cooled. A yeast solution was then made by combining active dry yeast, sugar, and warm water to stimulate metabolic activity.

The yeast mixture was divided into five groups:

a control group with no UV exposure

a UV-exposed group with only water

three UV-exposed groups treated with low, medium, and high concentrations of birch extract.

The UV groups were exposed to ultraviolet light for two minutes at a distance of 10 cm.

Cell survival was measured by shining an LED light through each sample and recording light intensity using a phone light meter, indicating optical density. Metabolic activity was measured by observing CO₂ production through the height of bubbles or foam after 20 minutes. Each test was repeated three times to improve reliability, and average values were calculated.

This method allowed for a controlled comparison of how different concentrations of birch root extract influence yeast cell survival and activity under UV stress.

The results of this investigation show a clear and consistent effect of ultraviolet (UV) radiation and birch root extract on yeast cell activity and metabolism. Optical density (light transmission, lux) was used to measure cell activity, while carbon dioxide (CO₂) production (foam height, cm) was used to assess metabolic activity.

For optical density, the No UV + Water (Control) group had the highest mean value (82.00 lux), indicating optimal cell activity under normal conditions. In contrast, the UV + Water group showed a significant decrease (60.00 lux), demonstrating that UV radiation negatively affects yeast cells, likely by damaging DNA and disrupting cellular processes.

The addition of birch root extract resulted in a steady increase in optical density as concentration increased. The Low Extract group showed partial recovery (65.00 lux), while the Medium Extract group improved further (71.00 lux). The High Extract group reached 77.33 lux, approaching the control level. This pattern shows a clear dose-dependent effect, suggesting that higher concentrations of birch root extract provide stronger protection against UV-induced damage.

The standard deviation values for optical density (SD= 1.00-1.15) were low across all groups, indicating consistent and reliable results. The slightly higher variation in the High Extract group (SD= 1.15) may reflect small biological differences in response to higher concentrations.

A similar trend was observed in CO₂ production. The Control group had the highest mean value (4.83 cm), indicating strong metabolic activity. The UV + Water group showed a sharp decrease (2.07 cm) , confirming that UV exposure reduces yeast metabolism.

With the addition of birch root extract, CO₂ production increased with concentration. The Low Extract group showed partial recovery (2.90 cm), while the Medium Extract group increased further (3.77 cm).The High Extract group reached 4.37 cm, again approaching control levels. This indicates that birch root extract helps restore metabolic activity in UV-stressed yeast cells.

The standard deviation values for CO₂ production (SD= 0.06-0.15) were also low, showing high consistency across trials. Slightly higher variation in the Control and High Extract groups (SD= 0.15) may be due to minor differences in yeast activity or measurement precision.

Figures 1 and 2 support these findings, showing a decrease in yeast activity under UV exposure and a gradual recovery with increasing extract concentration. The small error bars (±1 SD) further confirm the reliability of the data.

Overall, the results demonstrate that UV radiation reduces yeast cell activity and metabolism, while birch root extract provides a protective effect that increases with concentration. The consistent trends observed in both optical density and CO₂ production strengthen the conclusion that birch extract improves both cell survival and metabolic function under UV stress.

In conclusion, my investigation suggests that birch root extract can help protect yeast cells from UV-induced damage. Higher concentrations of the extract provided stronger protection, maintaining cell survival and metabolic activity closer to the unexposed control. These findings support the idea that birch, a culturally significant plant in First Nation communities, may have natural protective properties against UV stress. While this study used yeast as a model, the results show the potential for birch extract to be explored further as a natural solution for UV-related challenges, such as snow blindness, in northern communities like Gods Lake Narrows.

If I could continue this project with all the materials and a proper lab, I would focus on three things:

Test birch extract on human or animal cells to see how it protects skin and eyes from UV.

Try different ways to make the extract to find the most effective method.

Make a safe, simple birch-based preparation and test it in real northern conditions.

With a full lab and materials, I could do these experiments more accurately and learn more about how birch root extract protects against UV damage.

I would like to sincerely thank the School Board and Administration for allowing this science fair to take place, and the Science Fair Committee for organizing the event and providing support throughout the process. I am especially grateful to my science teacher for guiding me with advice, encouragement, and assistance during my project. I would also like to thank the Keewatin Regional Science Fair organizers for giving me the opportunity to advance and represent my work at the Canada-Wide Science Fair (CWSF).

I also want to thank my family and friends for their constant support, motivation, and encouragement. Above all, I thank the Creator Almighty for giving me the wisdom, patience, and strength to complete this investigation.

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Pan, L., Smith, J., & Lee, A. (2015). Medicinal plants of the genus Betula: Traditional uses and a phytochemical-pharmacological review. Journal of Ethnopharmacology. https://pmc.ncbi.nlm.nih.gov/articles/PMC7126499/

PubMed. (2019). Antioxidant activity of dry birch (Betula pendula) leaves extract. https://pubmed.ncbi.nlm.nih.gov/31188766/

Vitalibrary. (2025). Birch bark extract: Natural joint pain relief, skin healing, and dosage guide. https://vitalibrary.com/birch-bark-extract-joint-skin-guide/