Hydrolysable tannin polyphenols in pomegranate and phenolic acids in date fruit and seeds are potent antioxidants and anti-atherogenic agents, and thus, in the present study we investigated the possible benefits of combining them in vivo in atherosclerotic apolipoprotein E KO (E⁰) mice, compared with the individual fruit. In vitro studies revealed that the date seed extract contains more polyphenols than Amari or Hallawi date extracts, and possesses a most impressive free radical scavenging capacity. Similarly, pomegranate juice (PJ), punicalagin, punicalain, gallic acid, and urolithins A and B are very potent antioxidants. E⁰ mice consumed 0.5 μmol gallic acid equivalents (GAE) per mouse per day of PJ, Hallawi extract, date seed extract, or a combination for 3 weeks. Consumption of the combination was the most potent treatment, as it decreased serum cholesterol and triglyceride levels, and increased serum paraoxonase 1 (PON1) activity. Consumption of the combination also significantly reduced mouse peritoneal macrophage (MPM) oxidative stress, MPM cholesterol content, and MPM LDL uptake. Finally, the lipid peroxide content in the aortas of the mice significantly decreased, and the PON lactonase activity of the aortas increased after treatment with the combination. We thus conclude that consumption of pomegranate, together with date fruit and date seeds, has the most beneficial anti-atherogenic effects on E⁰ mice serum, macrophages, and aortas, probably due to their unique and varied structures.