Nutri People from Higher Nature

general-health - The nutrition status of the nation and folic acid fortification of food

The most recent National Diet and Nutrition Survey (NDNS) has just been published. It is funded by the Department of Health and is carried out by a consortium of three organisations; the National Centre for Social Research (NatCen), MRC Human Nutrition Research (HNR) and the University College London Medical School. 

The survey covers all four countries of the UK and is designed to be representative of the nutritional status of the UK population. This latest survey was carried out between February 2008 and June 2009 and involved 1,131 participants aged from 1.5 years upwards. It is based on a four-day food survey and, in each case, included two weekend days. This is important to note, as intake of food can change at the weekends, with typically more alcohol and takeaways being consumed on Fridays and Saturdays. Sunday provided a higher meat and vegetable intake for all age groups, most likely due to Sunday lunch. Vitamin and mineral levels are taken from food only and do not include any supplements. They are measured against the UK Reference Nutrient Intake. 

The key findings of the survey include(1)

These results show that, although slightly better than in previous years, there are still many causes for concern in our nation’s eating habits and nutritional status. 

The poor state of our nation’s health again brings up the thorny issue of food fortification. The Food Standards Agency is certainly considering mandatory fortification of bread or flour with folic acid to reduce the incidence of neural tube defects(2). The Scientific Advisory Committee on Nutrition (SACN), an independent scientific committee that advises the Government on nutrition, estimated that there are between 700 and 900 pregnancies affected by neural tube defects each year in the UK and are recommending fortification to reduce these numbers. Recent research has also highlighted the importance of B vitamins for brain function(3), and given the results of the latest NDNS, the answer to our nation’s poor nutritional status, could be the fortification of foods? 

In the past, food fortification has been extremely successful in reducing nutritional deficiencies, such as iodide, to prevent goiter, and thiamine, to prevent beriberi(4), but today, the Government faces different problems when considering fortification. Deficiencies are now often limited to a subset of the population and the appropriate dosage of the nutrient needs to be found, so it that is effective and not toxic. Large dosages of certain nutrients may cause harm, e.g. vitamin A and perhaps folic acid.

After the United States and Canada began fortification with folic acid in 1996 and 1997, respectively, their incidences of colorectal cancers have been significantly increasing year by year(5), leading researchers to suggest that folic acid supplementation may lead to colorectal neoplasia(6), which has since meant new guidelines on folic acid supplementation being issued. In a recent study undertaken in Chile, it was suggested that there had been an increase in colorectal cancer rates since the country began fortifying wheat flour with folic acid in the year 2000(7). It would appear that reported cases of colon cancer increased by 162% in people aged 45 to 64 and by 190% in people aged 65 to 79. However, it should be remembered that B12 deficiency may be masked and exaggerated by folic acid supplementation. This has been a criticism of single-nutrient fortification for decades. Recent data from the US National Health and Nutrition Examination Survey indicates that the function of B12 deteriorates as serum folate status increases in people who are deficient in B12. People with low B12 and high folate concentrations are also at particularly high risk of memory impairment and anaemia(8).

In a study entitled Is folic acid good for everyone?, published in a 2008 issue of the American Journal of Clinical Nutrition, researchers noted that high blood concentrations of folic acid may be related to decreased natural killer cell cytotoxicity and reduced response to antifolate drugs used against malaria, rheumatoid arthritis, psoriasis and cancer. In the elderly, a combination of high folate levels and low vitamin B12 status may be associated with an increased risk of cognitive impairment and anaemia and, in pregnant women, with an increased risk of insulin resistance and obesity in their children. The team also commented that folate has a dual effect on cancer, protecting against cancer initiation but facilitating progression and growth of preneoplastic cells and subclinical cancers, which are common in the population. The researchers therefore conclude that fortification could be harmful for some people(9).

Food fortification is not a simple answer. It does not take into consideration the needs and variability of the population, and it takes no account of the complex interactions between nutrients, or even the well-recognised relationship of folate and B12. There is also a concern that if people think their white bread is giving them all the nutrients they need, where is the incentive to seek out a healthy diet, or even recognise that they need balanced nutrition?

Many supplement companies, in light of this research, have taken the decision to reduce the amount of folic acid in everyday supplements, such as multivitamins and minerals, but still provide it in specific combinations for people who will benefit, such as pregnant women and those wishing to support brain and heart function, which allows an appropriate supplement programme to be formulated with individual needs in mind.