Lean-seafood intake reduces cardiovascular lipid risk factors in healthy subjects: results from a randomized...

Observational studies have strongly indicated an association between fish consumption and reduced risk of cardiovascular disease, but data from randomized controlled trials have been inconclusive.

Our primary outcome in this study was to elucidate the potentials of the 2 main dietary protein sources lean seafood and nonseafood to modulate fasting and postprandial lipids in healthy subjects. We hypothesized that lean-seafood intake would reduce cardiovascular lipid risk factors in healthy subjects more than would the intake of nonseafood protein sources.

This study was a randomized controlled trial with a crossover design. After 3-wk run-in periods and separated by a 5-wk washout period, 20 healthy subjects (7 men and 13 women) consumed 2 balanced diets that varied in main protein sources (60% of total dietary proteins from lean-seafood or nonseafood sources for 4 wk). At days 1 and 28 of each intervention, fasting and postprandial blood samples were collected before and after consumption, respectively, of test meals with cod or lean beef.

Relative to the nonseafood intervention, the lean-seafood intervention reduced fasting (relative difference by diets: 0.31 mmol/L; P = 0.03) and postprandial (P = 0.01) serum triacylglycerol concentrations. The lower serum triacylglycerol concentration was associated with reduced fasting triacylglycerol in chylomicrons and very-low-density lipoproteins (VLDLs) (P = 0.004), reduced fasting VLDL particle size (P = 0.04), and a reduced postprandial concentration of medium-sized VLDL particles (P = 0.02). The lean-seafood intervention prevented the elevated ratio of total cholesterol to HDL cholesterol in the fasted serum (P = 0.03) and postprandial serum (P = 0.01) that was observed after the nonseafood intervention.

The dietary protein source determines fasting and postprandial lipids in healthy individuals in a manner that may have an effect on the long-term development of cardiovascular disease. This study was registered at clinicaltrials.gov as NCT01708681.