Previous research has found that therapy with vitamin C may help heart failure patients by improving the function of their blood vessels.
"We can see that those with the highest intake of fruit and vegetables have a 15% lower risk of developing cardiovascular disease and a 20% lower risk of early death compared with those who very rarely eat fruit and vegetables," explained Dr Camilla Kobylecki, at the University of Copenhagen and Herlev and Gentofte Hospital. "At the same time, we can see that the reduced risk is related to high vitamin C concentrations in the blood from the fruit and vegetables."
Senior author Professor Boerge Nordestgaard, also from University of Copenhagen and Herlev and Gentofte Hospital, noted that while it has been long known that fruit and vegetables are healthy, the new data may be pinpointing more precisely why this is so.
"You can get vitamin C supplements, but it is a good idea to get your vitamin C by eating a healthy diet, which will at the same time help you to develop a healthier lifestyle in the long term, for the general benefit of your health," he said.
Writing in The American Journal of Clinical Nutrition, the Danish team tested the hypothesis that genetically high concentrations of plasma vitamin C, such as with high intake of fruit and vegetables, are associated with low risk of ischemic heart disease and all-cause mortality using a Mendelian randomisation approach.
Using DNA analysis techniques, the team found that people expressing a certain genetic allele known as SLC23A1 rs33972313 G has higher plasma vitamin C levels, and that these increased concentrations were also significantly associated with a lower risk of ischemic heart disease and all-cause mortality.
"Our data cannot exclude that a favorable effect of high intake of fruit and vegetables could in part be driven by high vitamin C concentrations," said the team.
Nordestgaard and colleagues are now continuing their work to determine which other factors, combined with vitamin C, have an impact on cardiovascular disease and death.
It should be pointed out that vitamin C supplements on the market may be full of fillers.
Intraveous injection of vitamin C is the most effective for of supplement and has been found to prevent damage induced by cancer-causing radiation, prevent gastric cancer, lung cancer, Alzheimer's disease, leukemia, prostate cancer, melanoma, breast cancer, smoke-induced atherosclerosis, infections, diabetes, heart failure damage, heart disease, age-related cataract, gout, inhibit HIV replication, and promote wound healing.