An occasional helping of liver and spinach might be useful in lessening your chances of a heart attack or stroke. While they might not be your favourite dinner, both are rich in folate, a B vitamin which helps to moderate some of the risk factors related to heart disease.
The question is, just how often do you have to tuck into this combination? A research team at the University of Ulster, Coleraine, is trying to measure how much folate one needs to lower a blood constituent called homocysteine. Elevated homocysteine levels are a powerful risk factor for heart disease and stroke, explained Dr Helene McNulty, who leads the research at the school of biomedical sciences in Coleraine.
Dr McNulty oversees a number of studies focusing on folate and its contribution to health. A £681,000 project funded by the UK Ministry for Agriculture, Forestry and Food, which began last September, looks at the bio-availability of folate in synthetic and natural forms. Another, on the use of folate to lower blood levels of homocysteine in healthy individuals, is in collaboration with Prof John Scott at Trinity College, Dublin, where Dr McNulty completed her Ph.D.
She also has funding from the Northern Ireland Chest, Heart and Stroke Association to study the interplay between nutritional and genetic factors in determining homocysteine levels of young adults.
"The focus of our work is the intake of folate for the prevention of disease," she explained. "At the end of the day we are interested to see something coming out of our work that can help healthy people. Real people who don't have disease want to know what they should eat to prevent disease."
Folate, or folic acid, is a B vitamin that is plentiful in green vegetables and also in liver. It was the centre of a nutritional research breakthrough in 1991 when it was discovered that spina bifida and related neural tube birth defects could be prevented if folate was given to mothers around the time of conception.
This prompted a flurry of research on folate and other roles it plays in the body. It was discovered that folic acid, with vitamin B12, was required to break down homocysteine. Raised levels of this substance are now known to be as important as cholesterol in assessing a person's risk of heart disease and it was established that low folic acid levels usually meant raised homocysteine.
Some individuals are "genetically predetermined" to have high homocysteine levels, she said. About one in 10 people in the Republic and slightly higher numbers in Northern Ireland have naturally elevated levels, so it is a widespread problem, she added.
Dr McNulty's group is studying whether a diet rich in folic acid can offset high homocysteine and so reduce heart disease risks. "If you lower your value, you lower your risk." Surprising findings in trials so far indicate that additional folic acid reduced homocysteine levels in two out of three subjects, even though these people all had apparently "normal" folic acid levels.
This probably points to the need to review what was considered normal in nutritional terms, Dr McNulty said. The currently accepted daily allowances may not be correct.
Green vegetables are the best natural source for folate; liver has higher levels, but women are advised during pregnancy to avoid liver because it can also contain very high vitamin A levels.
Dr McNulty was the winner of the inaugural Royal Irish Academy Award in Nutritional Sciences last autumn. The award recognises outstanding research in nutritional sciences by a researcher aged under 45. She is a senior lecturer in human nutrition and dietetics in the school of biomedical sciences.
