Taurine may reduce inflammation, oxidation, and glucose levels. Can sardines, a type of fish rich in taurine, benefit older people at high risk of developing type 2 diabetes?

The study

In this 1-year randomized controlled trial, 152 prediabetics (fasting glucose: 100–124 mg/dL) aged ≥65 received nutrition counseling based on the guidelines of the American Diabetes Association. They were divided between a sardine group (200 g/week) and a control group.

The primary outcome was the rate of newly diagnosed type 2 diabetes. The secondary outcomes were dietary biomarkers, beta-cell function, insulin resistance, and the levels of insulin, glucose, and adiponectin.

The results

After the trial, a third of each group were no longer prediabetic (their glucose levels were normal). However, the percentage of people at the highest risk of developing type 2 diabetes was now lower in the sardine group than the control group (−4.9% vs. −29.6%).

Sardines increased HDL (+3.43 mg/dL) and adiponectin (+1.27 mg/mL) and decreased triglycerides (−11.13 mg/dL), blood pressure (systolic −4.34 mmHg, diastolic −2.24 mmHg), and insulin resistance (HOMA-IR: −0.47 mmol/L).

Compared to the control group, the sardine group consumed more taurine (43.22 g/day), fluorine (33.58 μg/day), vitamin D (1.87 μg/day), and omega−3 fatty acids (1,070 mg/day), including EPA (500 mg/day) and DHA (550 mg/day). Changes in erythrocyte-membrane fatty acids (a measure of dietary fatty-acid intake over time) were found only in the sardine group, with a decrease of five types of omega−6s and an increase of three types of omega−3s.


Whole sardines are more nutritious than fillets:[1] 100 grams of whole sardines contain 1,200 mg of EPA, 870 mg of DHA, over 700 mg of calcium, nearly 300 mg of taurine, and 15 µg of vitamin B12. Best not go overboard on tinned sardines, though, since a recent case study found that a man who regularly ate tinned sardines (and other seafoods) developed arsenic poisoning.[2]

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This Study Summary was published on June 4, 2021.


  1. ^Inger Aakre, Annbjørg Bøkevoll, Jamal Chaira, Fatima Zohra Bouthir, Sylvia Frantzen, Anette Kausland, Marian KjellevoldVariation in Nutrient Composition of Seafood from North West Africa: Implications for Food and Nutrition SecurityFoods.(2020 Oct 21)
  2. ^Leen Othman, Abeer Nafadi, Saleh H Alkhalid, Nadia MazraaniArsenic Poisoning due to High Consumption of Canned Sardines in Jeddah, Saudi ArabiaCureus.(2021 Jan 19)