From the Research
Starting (fasting) does not significantly affect PSA test results. You can eat and drink normally before a PSA blood test without worrying about it impacting your results. Unlike some other blood tests that require fasting, the PSA test measures a protein produced by the prostate gland that circulates in the blood regardless of recent food or fluid intake. However, there are other factors that can affect PSA levels that you should be aware of.
Factors Affecting PSA Levels
- Sexual activity (ejaculation) within 24-48 hours before the test can temporarily raise PSA levels, so it's recommended to abstain for 1-2 days before testing 1.
- Vigorous exercise, especially cycling, and certain medical procedures like digital rectal exams or prostate biopsies can also temporarily elevate PSA.
- Some medications, including certain prostate medications like finasteride (Proscar) or dutasteride (Avodart), can lower PSA levels, as shown in a study comparing the efficacy of finasteride and dutasteride in treating males with benign prostatic hyperplasia 2.
Medications and PSA Levels
Studies have shown that dutasteride and finasteride can reduce PSA levels, with dutasteride producing a greater decrease in IPSS and PSA compared to finasteride 2, 3. However, the most recent and highest quality study, a systematic review and meta-analysis published in 2022, found that dutasteride is better than finasteride in improving the Qmax of patients with BPH, but there was no statistically significant difference in symptoms, PV, PSA, QOL, or adverse reactions 3.
Recommendation
For the most accurate results, inform your healthcare provider about any medications you're taking and follow their specific pre-test instructions. It's essential to consider the potential effects of medications and other factors on PSA levels to ensure accurate test results and proper interpretation.