Folate fortification: potential impact on folate intake in an older population

Food and nutrient consumption trends in older Australians: a 10-year cohort study

BACKGROUND/OBJECTIVES

Few longitudinal population-based cohort studies of older people have described dietary intakes over time. The objective of this study was to assess changes in the food and nutrient intake in a cohort of older Australians, using longitudinal data collected over 10 years.

SUBJECTS/METHODS

Population-based cohort of people aged 49 years and over at baseline (82% of those eligible) living in two postcode areas, west of Sydney. In 1992-1994, 3654 people were examined; 2334 were reexamined after 5 years and 1952 after 10 years (75% survivors at both examinations). A 145-item food frequency questionnaire was used to assess food and nutrient intake on each occasion, and 1166 participants provided usable dietary data at all three examinations.

RESULTS

Energy and sugar intake significantly increased among women over the 10-year period (P-value for trend <0.0001). Long-chain omega-3 fatty acid and fish intake significantly increased in both men and women (P-value for trend <0.0001). Folate intake significantly increased in both men and women (women: 325 dietary folate equivalents (DFE) vs 403 DFE; men: 346 DFE vs 425 DFE, P<0.0001). Wholemeal/grain bread consumption decreased in both men and women (P-value for trend <0.0001).

CONCLUSIONS

Many of the observed changes in diet over the 10-year period were consistent with current population dietary recommendations. Some changes, however, appear to have been due to poorer dietary choices. This information could be used to inform nutrition policy and programs targeted to older persons. These data highlight the need to identify barriers to better food choices.

Age-associated B vitamin deficiency as a determinant of chronic diseases

The number of elderly individuals is growing rapidly worldwide and degenerative diseases constitute an increasing problem in terms of both public health and cost. Nutrition plays a role in the ageing process and there has been intensive research during the last decade on B vitamin-related risk factors in vascular and neurological diseases and cancers. Data from epidemiological studies indicate that subclinical deficiency in most water-soluble B vitamins may occur gradually during ageing, possibly due to environmental, metabolic, genetic, nutritional and pathological determinants, as well as to lifestyle, gender and drug consumption. Older adults have distinct absorption, cell transport and metabolism characteristics that may alter B vitamin bioavailability. Case–control and longitudinal studies have shown that, concurrent with an insufficient status of certain B vitamins, hyperhomocysteinaemia and impaired methylation reactions may be some of the mechanisms involved before a degenerative pathology becomes evident. The question that arises is whether B vitamin inadequacies contribute to the development of degenerative diseases or result from ageing and disease. The present paper aims to give an overview of these issues at the epidemiological, clinical and molecular levels and to discuss possible strategies to prevent B vitamin deficiency during ageing.

Widespread Micronutrient Inadequacies Among Adults in Prince Edward Island

Purpose: The prevalence of micronutrient inadequacies was assessed among adult residents of Prince Edward Island (PEI) in the PEI Nutrition Survey.

Methods: A peer-reviewed protocol was used in this crosssectional survey, in which 24-hour recalls were administered during in-home interviews. A stratified random sample of 1,995 adults aged 18 to 74 participated. Median nutrient intakes with and without supplements were calculated; intakes were adjusted for day-to-day variability. Chi-square testing was used to assess differences in prevalence of inadequacy by age and sex.

Results: Most of the sample (more than 90%) had folate intakes below the Estimated Average Requirement (EAR). Magnesium and vitamin C intakes were low in more than 50% of the sample. Iron intakes were adequate in all groups except women aged 19 to 50, 29% of whom had intakes below the EAR. Women were more likely than men to have inadequate intakes. Median calcium intakes fell below recommendations for all age and sex groups. Supplement use had little impact on dietary adequacy in this sample.

Conclusions: This study underscores the need for public health interventions designed to reduce the very high prevalence of nutrient inadequacies in the PEI adult population. In addition, education is needed on the selection of appropriate vitamin and mineral supplements.

Prevalence of low serum folate and vitamin B12 in an older Australian population

OBJECTIVE

To examine the prevalence of low serum folate and vitamin B12, in association with elevated serum homocysteine, in a representative sample of older Australians.

METHODS

During 1997-2000, 3,508 persons aged 50+ years were examined in a population-based cohort study conducted in two postcodes, west of Sydney, Australia. Of these, 2,901 participants (82.7%) provided fasting blood for estimates of serum folate, vitamin B12 and total homocysteine.

RESULTS

Low serum B12 (< 185 pmol/L) was found in 22.9% of participants and low serum folate (< 6.8 nmol/L) in 2.3% of participants. Among those people with very low serum vitamin B12 (< 125 pmol/L) and low serum folate, 51% had elevated homocysteine.

CONCLUSIONS

Low serum levels of vitamin B12 and elevated serum homocysteine are relatively frequent in older Australians.

IMPLICATIONS

Appropriate public health action should be considered to reduce the prevalence of low serum vitamin B12 and elevated homocysteine in older Australians.

A comprehensive evaluation of food fortification with folic acid for the primary prevention of neural tube defects

BACKGROUND: Periconceptional use of vitamin supplements containing folic acid reduces the risk of a neural tube defect (NTD). In November 1998, food fortification with folic acid was mandated in Canada, as a public health strategy to increase the folic acid intake of all women of childbearing age. We undertook a comprehensive population based study in Newfoundland to assess the benefits and possible adverse effects of this intervention. METHODS: This study was carried out in women aged 19-44 years and in seniors from November 1997 to March 1998, and from November 2000 to March 2001. The evaluation was comprised of four components: I) Determination of rates of NTDs; II) Dietary assessment; III) Blood analysis; IV) Assessment of knowledge and use of folic acid supplements. RESULTS: The annual rates of NTDs in Newfoundland varied greatly between 1976 and 1997, with a mean rate of 3.40 per 1,000 births. There was no significant change in the average rates between 1991-93 and 1994-97 (relative risk [RR] 1.01, 95% confidence interval [CI] 0.76-1.34). The rates of NTDs fell by 78% (95% CI 65%-86%) after the implementation of folic acid fortification, from an average of 4.36 per 1,000 births during 1991-1997 to 0.96 per 1,000 births during 1998-2001 (RR 0.22, 95% CI 0.14-0.35). The average dietary intake of folic acid due to fortification was 70 μg/day in women aged 19-44 years and 74 μg/day in seniors. There were significant increases in serum and RBC folate levels for women and seniors after mandatory fortification. Among seniors, there were no significant changes in indices typical of vitamin B12 deficiencies, and no evidence of improved folate status masking haematological manifestations of vitamin B12 deficiency. The proportion of women aged 19-44 years taking a vitamin supplement containing folic acid increased from 17% to 28%. CONCLUSIONS: Based on these findings, mandatory food fortification in Canada should continue at the current levels. Public education regarding folic acid supplement use by women of childbearing age should also continue.

Oral Synthetic Folic Acid and Vitamin B12Supplements Work-If One Consumes Them

Oral supplements of synthetic folic acid and vitamin B12 are very effective in increasing blood levels of the vitamins and are known to prevent birth defects and cardiovascular diseases.

Effect of folic acid fortification of foods on folate intake in female smokers with cervical dysplasia

OBJECTIVE

We investigated the effect of folic acid fortification of enriched cereal grains on folate intake in women of predominantly childbearing age at high risk for cervical cancer.

METHODS

Subjects in this cross-sectional study were 77 women randomized between November 1999 and December 2000 in the Women's Intervention to Stay Healthy (WISH), a clinical trial evaluating the effect of a tobacco control intervention on the progression of cervical dysplasia. All subjects were cigarette smokers, had a previously abnormal Papanicolaou test, and were positive for high-risk human papillomavirus at entry. Dietary intake was assessed with food-frequency questionnaires completed at the baseline visit for WISH. The effect of folic acid fortification on folate intake was assessed by using pre- and postfortification folate databases to estimate folate intake.

RESULTS

Mean folate intake assessed with the postfortification database was 63% higher than intake assessed with the prefortification database: 417 versus 256 microg/d of dietary folate equivalents (P < 0.0001). The proportion of subjects below the estimated average requirement for folate was smaller after fortification than before fortification: 40.3% versus 75.3% (P < 0.0001). Several foods, including white bread, cheese dishes, spaghetti, and rice, became major sources of folate as a result of fortification.

CONCLUSIONS

Folic acid fortification resulted in an increased intake of folate in these subjects. However, even with fortification, folate intake in a large proportion of these women remained below recommended levels. These results should be considered before decisions regarding future levels of folic acid fortification are made.

Scientific evidence supporting folic acid fortification of flour in Australia and New Zealand

BACKGROUND

Fortification of flour with folic acid is a safe, sustainable, and cost-effective approach for preventing spina bifida and anencephaly, and it is likely to confer multiple health benefits to the adult population. Scientists and advocates are bringing this intervention to the attention of policymakers in countries around the world, and consequently the demand for sound, science-backed policy rationale is increasing.

METHODS

We recently prepared this scientific review for scientists, physicians, and advocates who were promoting mandatory folic acid fortification of flour in Australia and New Zealand. This short document references the most relevant published scientific data and national and international recommendations from other countries and presents an argument for fortification based on demonstrated need, proven effectiveness, safety, and multiple health benefits.

CONCLUSIONS

With some modifications, this document could be utilized in other countries considering fortification of flour or other staple products with folic acid.

Persistence of vitamin B12 insufficiency among elderly women after folic acid food fortification

OBJECTIVE

To estimate the associated risk of folate and vitamin B12 (B12) insufficiency, as well as vitamin repletion, following folic acid food fortification.

DESIGN

Retrospective cross-sectional study over a 5-year period.

SETTING

Two large laboratory databases in the provinces of Ontario and British Columbia, Canada.

PARTICIPANTS

Canadian women aged 65 years and over who underwent concomitant clinical testing of serum folate and B12 during the pre-fortification period of January 1996 to December 1997 in Ontario (n = 733) and British Columbia (n = 3839), and in the near-complete post-fortification period of January 1998 to December 2000 in Ontario (n = 4415) and British Columbia (n = 6677).

MEASUREMENTS

Geometric mean concentrations of serum folate and B12 before and after folate fortification. Prevalence ratios (PR) were used to separately compare the post- and pre-fortification period rates of folate deficiency (below 6.0 nmol/L); B12 insufficiency (below 150 pmol/L); and B12 insufficiency in combination with supraphysiological concentrations of serum folate (above 45 nmol/L).

RESULTS

The mean baseline folate and B12 concentrations were similar between provinces. Using the combined provincial data, the mean serum folate concentration increased by 64% after fortification, from 14.8 to 24.2 nmol/L (p < 0.001). The average B12 concentration increased from 280 to 300 pmol/L, which was more pronounced in BC (p < 0.001) than in Ontario (p = 0.16). The prevalence of folate deficiency declined from 6.3% to 0.88% after fortification (PR 0.14, 95% confidence interval [CI] 0.11-0.18), while the decline in B12 deficiency was less pronounced (PR 0.78, 95% CI 0.71-0.86).

CONCLUSIONS

The prevalence of combined B12 insufficiency with supraphysiological concentrations of serum folate increased from 0.09% pre-fortification to 0.61% post (PR 7.0, 95% CI 2.6-19.2). The introduction of folic acid food fortification was associated with a substantial improvement in the folate status of Canadian women aged 65 years and older, paralleled by a large decline in the rate of folate deficiency. Improvement in the B12 status of these women was far less pronounced. Because the prevalence of combined B12 insufficiency and supraphysiological concentrations of serum folate may have increased with folic acid food fortification, consideration should be given to confirming this finding, and possibly, to the addition of B12 to folate fortified foods.

News and views on folate and elderly persons

Elderly persons are especially exposed to folate deficiency, where normal/subnormal folate levels do not exclude tissue deficiency. Accompanying diseases, medication, and lifestyle factors may contribute to/cause deficiency. Symptoms of deficiency can be hematological, neurological, or neuropsychiatric, but it is likely that there are also cardiovascular manifestations as well as associations with malignancies. The physician should make an individualized investigation to establish the probable cause. Among the available determinants of the folate/cobalamin state, plasma homocysteine (Hcy) is a swift and sensitive marker and has the strongest connection to cognitive function. The association is generally stronger between Hcy levels and symptoms than between vitamin-related levels and symptoms. The duration as well as the severity of symptoms are of importance in terms of the improvement of neurological and neuropsychiatric symptoms when substitution is performed. The issue of general folate fortification of flour is complex, and there are as many pros and cons as there are countries in which it is considered to be launched. It is important to bear in mind that in our modern society, deficiency of folate/cobalamin--overt or latent--mainly is a problem of the elderly and a challenge to the doctor.