Research notes
Boost anti-oxidant absorption by adding citrus to green tea
Research by Purdue University in Indiana, published in Molecular Nutrition and Food Research (November 2007), suggests that combining citrus juice or vitamin C with green tea or its extracts could increase the absorption of anti-oxidants from the tea up to 13-fold. The researchers used a simulated gastric and small-intestinal digestion system to model the effects of juices, creamers and other additives on the absorption of anti-oxidants from tea. The four primary polyphenols found in fresh tea leaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin. According to researchers, the catechins are relatively unstable in non-acidic environments, such as the intestines, and less than 20 per cent of the total remains after digestion. Adding citrus juice or vitamin C led to increased stability of the catechins.
Low vitamin D linked to pregnancy complications
New research published in the Journal of Clinical Endocrinology and Metabolism has linked low vitamin D levels in mothers to a five-fold increased risk of pre-eclampsia, a serious complication in pregnancy that can lead to foetal death. Pre-eclampsia is marked by soaring blood pressure and swelling of the hands and feet, and is the leading cause of premature delivery and maternal and foetal illness and death worldwide. The researchers concluded that vitamin D supplementation in early pregnancy should be explored for preventing pre-eclampsia and promoting the health of the foetus. Further study is needed to determine recommended levels of vitamin D, since the researchers noted the trial supplementation of up to 400 IU daily was not sufficient for some women to reduce their risk.
Carotenoids linked to lower AMD risk
Age-related macular degeneration (AMD) is the leading cause of legal blindness for people over 55 years of age in the western world. AMD is a degenerative retinal disease that causes central vision loss and leaves only peripheral vision. The incidence of AMD is expected to triple by 2025, which is why research published in the Archives of Ophthalmology in September 2007 is good news. Researchers have again found that supplementing with the carotenoids lutein and zeaxanthin have been associated with a lower risk for AMD. These carotenoids are found in leafy green vegetables, corn, egg yolks, squash, broccoli and peas. They are thought to reduce the risk of AMD by absorbing blue light that could damage the macula, preventing free-radicals from damaging eye cells and strengthening eye cell membranes.