A high sodium intake is associated with impairments in vascular function, including endothelial-dependent dilation (EDD). Recent evidence suggests the reduction in EDD observed with high sodium diets may be associated with oxidative stress, even though specific enzymatic sources of the sodium-induced oxidative stress have yet to be identified. Results from epidemiological studies suggest benefits of dairy consumption, including reduced blood pressure and reduced arterial stiffness. However, there is limited data exploring the impact of dairy cheese on vascular function. Alba and colleagues report the results of a study exploring this question in the January 2020 issue of The Journal of Nutrition.
Subjects (n=11) in this work did not exhibit salt-sensitive increases in blood pressure. They were randomly assigned to receive four interventions in a randomized, cross-over design. The treatments included: 1) low sodium (1500 mg/day) and no dairy; 2) low sodium and high cheese (170 g/day); 3) high sodium (5500 mg/day) and no dairy; or 4) high sodium and high cheese. Subjects consumed each diet for 8 days and on the last day EDD was measured after a challenge of acetylcholine (ACh) alone, or with a nitric oxide synthase inhibitor, a nonspecific antioxidant, a NAD(P)H oxidase inhibitor, or a superoxide scavenger.
The high sodium diet attenuated the response to ACh, in comparison to the low sodium diet. However, the responses were not different in the low sodium and high cheese, or the high sodium and high cheese periods, when compared with the low sodium no cheese period. Administration of the antioxidant, NAD(P)H oxidase inhibitor, or superoxide scavenger increased ACh-induced dilation of the vessels with the high sodium no cheese treatment, but not during the other treatment periods. The authors concluded that cheese, even in a high sodium diet, helps to preserve EDD by decreasing superoxide radicals. They suggest that the sodium in cheese does not have the same impact as sodium derived from non dairy sources and may serve to reduce cardiovascular risk among salt-insensitive, older adults.
References Alba BK, Stanhewicz AE, Dey P, Bruno RS, Kenney WL, Alexander LM. Controlled feeding of an 8-d, high-dairy cheese diet prevents sodium-induced endothelial dysfunction in the cutaneous microcirculation of healthy, older adults through reductions in superoxide. Journal of Nutrition, https://doi.org/10.1093/jn/nxz205. .
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