In a small study supported by the California Walnut Commission, diets containing walnuts or fish both derived cardiovascular benefit – although each diet had a different effect on lipid parameters.
Twenty-five adults with normal to mild hyperlipidemia were randomly assigned to a control diet that did not include nuts or fish, a walnut diet providing 42.5 grams of walnuts (about 1.5 ounces), or a fish diet containing 113 grams (4 ounces) of fish twice a week. The feeding periods lasted for four weeks each, and all participants crossed over to the others. All diets contained the same number of calories.
Compared to the control diet, the walnut diet resulted in reductions in total and LDL cholesterol. The fish diet showed no improvements in total and low-density lipoprotein (LDL or “bad”) cholesterol, but reduced triglycerides and raised high-density lipoprotein (HDL or “good”) cholesterol.
Nutrition Tip: Although walnuts are a source of omega-3 fat (derived from the plant form of omega-3, called alpha-linolenic acid), they do not produce the same impact on lipids as fish consumption. This study just adds to the growing body of evidence linking both nuts and fish to improved overall cardiovascular health. It also encourages us to choose a variety of food sources rather than a single food or nutrient to improve our hearts.
Rajaram S, Haddad EH, Mejia A, Sabate J. Walnuts and fatty fish influence serum lipid fractions in normal to mildly hyperlipidemic individuals: a randomised controlled study. AJCN 2009; 89(5):1657S-1663S
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Written by Melissa Ohlson, M.S, R.D., L.D., Preventive Cardiology and Rehabilitation.