Antihypertensive effect of valyl-tyrosine, a short chain peptide derived from sardine muscle hydrolyzate, on mild hypertensive subjects
Kawasaki T, Seki E, Osajima K, Yoshida M, Asada K, Matsui T, et al.. J Hum Hypertens. 2000; 14(8):519–523.
PubMed 10962520 · doi:10.1038/sj.jhh.1001065
Compares people who got the treatment with people who did not.
- Who or what was studied
- 29 adults with high-normal blood pressure or mild hypertension
- Design
- Randomised, double-blind, placebo-controlled: 3-week run-in, 4 weeks of treatment, 4-week recovery
- Dose
- 3 mg of valyl-tyrosine in a 100 ml drink, twice a day
- Duration
- 4 weeks of treatment
What it found
On the sardine peptide, systolic and diastolic blood pressure fell by 9.7 and 5.3 mm Hg after one week and by 9.3 and 5.2 mm Hg after four weeks (P < 0.001), with no change on placebo. Pressure crept back up during the recovery period. Blood markers fitted ACE inhibition (angiotensin II and aldosterone fell), and no adverse effects were detected.
What it doesn't show
A single small, short trial in people with mild hypertension, and nothing else in this hub replicates it. It tested one defined peptide (valyl-tyrosine) in a drink, not marine collagen or fish hydrolysate products in general.
Funding and conflicts of interest
No funding or conflict-of-interest statement appears in the PubMed record. Check the full text.
Summary written from the study's abstract and checked against PubMed on November 9, 2026. How we check studies. Educational information, not medical advice.