ARS | Publication request: Potato consumption on oxidative stress, inflammatory damage and immune response in humans

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 23, 2010
Publication Date: September 24, 2010
Citation: Kaspar, K.L., Park, J.S., Brown, C.R., Mathison, B.D., Navarre, D.A., Chew, B.P. 2010. Potato consumption on oxidative stress, inflammatory damage and immune response in humans. Journal of Nutrition. 141:108-111.

Interpretive Summary: Specialty foods may have benefits for human health. Potato is a good source of vitamin C and potassium. However, some potatoes have high levels of other phytonutrients. Purple-fleshed potato may have extremely high levels of anthocyanins and other phenolic acids. Yellow-fleshed potatoes have high levels of certain kind of carotenoids. The principal carotenoids found in potato are lutein and zeaxanthin. Both of these compounds are major constituents of the human retina and must be obtained from the diet. The study reported here compared white-fleshed, dark yellow-fleshed and deep purple-fleshed potatoes, where the human subjects ate the potatoes every day for six weeks. The groups eating yellow and purple flesh potatoes showed a reduction in damage to their DNA. DNA damage often leads to cancerous cell multiplication, and any treatment that protects DNA would lessen that risk. In addition, the group eating the purple potatoes showed a reduction of total inflammation. This test (C-reactive protein) shows whether a person is in danger of a heart attack, and can also be an indicator that a heart attack is occurring. A lower level of inflammation indicates a better state of health. In addition, both the yellow and purple potatoes resulted in a higher expression of the immune system, providing the participants an enhanced ability to fight off microbes that might lead to illness. Since Americans eat an average of 140 pound of potatoes each year, these types of phytonutrient-enhanced potatoes might be a good way to increase the health status of the population through diet.

Technical Abstract: Pigmented potatoes contain high concentrations of antioxidants including phenolic acids, anthocyanins and carotenoids, which are implicated in the inhibition or prevention of cellular oxidative damage and chronic disease susceptibility. Research has demonstrated the beneficial effects of antioxidant supplementation on immune cell function. The purpose of this study was to assess the effects of pigmented potato consumption on oxidative stress biomarkers, inflammation and immune response in healthy males. Free living healthy male participants (18-40 yr; n=12/group) were given 150 g of cooked White-, Yellow- or Purple-flesh potatoes once a day for 6 wk in a single-blinded study. Blood was collected at baseline and wk 6 to analyze total antioxidant capacity, DNA damage (8-OHdG), protein oxidation, lipid peroxidation, C-reactive protein (CRP), cytokines (IL-6,TNF-a,IFN-'), lymphoproliferation, NK cytotoxicity and phenotypes. Participants fed Purple-flesh potatoes had lower (P < 0.08) CRP concentrations compared to those fed White–flesh potatoes. Lower concentrations of 8-OHdG were observed in subjects fed either Purple (P < 0.08) or Yellow (P < 0.03) potatoes as compared to those fed White potatoes. Total Tc cells were lower (P < 0.04) in Purple compared to the White potato group. Subjects fed Yellow potatoes tended to have lower (P > 0.1) B and NK cell subpopulations and higher (P > 0.1) T cell populations than those fed White potatoes. Similarly, subjects fed Purple potatoes tended (P > 0.1) to have higher B and NK cell populations and lower T cell populations. Pigmented potato consumption reduced inflammation and DNA damage, and modulated immune cell phenotype in male subjects.