Enriched Cereal Grain Products Research Articles

Modeling the level of fortification and post-fortification assessments: U.S. experience.

Mandatory fortification of enriched cereal-grain products became effective in the United States on January 1, 1998. This fortification was undertaken to assist women of child-bearing age in increasing their intake of folic acid to reduce their risk of having a pregnancy affected by a neural tube birth defect. The process by which the Food and Drug Administration modeled the level of fortification with folic acid illustrates the complex issues and general principles that emerge when fortification of a nation's food supply is evaluated as a means of addressing a public health concern. The effectiveness of fortification for a target population and safety for the much larger general population impose conflicting challenges that must be considered concurrently when making decisions regarding fortification. Recent data show improved folate status and apparent decreases in risk of neural tube birth defects in the U.S. Much about the long-term effects of the fortification program remains unknown and careful monitoring over time will be necessary to ensure that the program functions as intended.

Rates of twinning before and after fortification of foods in the US with folic acid, Texas, 1996 to 1998.

Several investigators have reported a 40% increase in the prevalence of twinning among women who have taken folic acid or multivitamins containing folic acid at the time of conception. Given that infant morbidity and mortality are greatly increased among twins, such a large increase in twinning could have serious implications. We undertook this study to determine if US fortification of enriched cereal-grain products with folic acid was associated with an unexpected increase in the prevalence of twinning in the state of Texas. We examined 1 003 207 deliveries conceived in Texas, between 1 January 1996 and 31 December 1998. We compared the prevalence of twin deliveries conceived before, during and after fortification with folic acid, mandated to begin on 1 January 1998. Comparing pregnancies conceived in 1997 with those conceived in 1996, we observed a 2.4% yearly increase in twinning, 1.024 [0.98, 1.07]. Comparing pregnancies conceived in 1998 with those conceived in 1997, we observed a 4.6% yearly increase in twinning, 1.046 [1.00, 1.09]. These increases were adjusted for maternal age, race, education, parity and season of conception. The size and pattern of these increases are consistent with the ongoing increase in twinning of 1-4% per year which began in the US prior to fortification.

Folic Acid Intake from Fortification in United States Exceeds Predictions

In 1996, the U.S. Food and Drug Administration issued a regulation requiring that all enriched cereal-grain products be fortified with folic acid by January 1998. An average increase in folic acid intake of 100 micro g/d was projected as a result of this fortification. The objective of the present study was to estimate the effect of this fortification on the intake of folic acid and total folate, and on the prevalence of individuals with inadequate folate intake and with high folic acid intake. We used data on food and nutrient intake from 1480 individuals who participated in the 5th and 6th examinations of the Framingham Offspring Cohort Study. Fortification was instituted during the 6th examination so that 931 participants were examined before its implementation (nonexposed) and 549 after implementation (exposed). Published data on total folate in enriched cereal-grain products were used to correct folate content in these foods to reflect fortification. Among nonsupplement users, folic acid intake increased by a mean of 190 [95% confidence interval (CI): 176, 204] micro g/d (P < 0.001) and total folate intake increased by a mean of 323 (95% CI: 296-350) micro g dietary folate equivalents (DFE)/d (P < 0.001) in the exposed participants. Similar increases were seen among supplement users exposed to fortification. The prevalence of exposed individuals with total folate intake below the estimated average requirement (320 micro g DFE/d) decreased from 48.6% (95% CI: 44.2-53.1%) before fortification to 7.0% (95% CI: 3.1-10.9%) after fortification in individuals who did not use folic acid supplements. This prevalence was approximately 1% or less for users of supplements both before and after fortification. Prevalence of individuals with folic acid intake above the upper tolerable intake level (1000 micro g folic acid/d) increased only among supplement users exposed to fortification (from 1.3 to 11.3%, P < 0.001). No changes in folic acid intake were observed over time in the nonexposed participants. By these estimations, folic acid fortification resulted in a mean increase in folic acid intake that was approximately twice as large as previously projected.

Folic Acid Fortification, Folate Status and Plasma Homocysteine

Folic acid fortification of enriched cereal-grain products (which became mandatory in the U.S. on January 1, 1998) was intended to increase folate intake among childbearing-aged women to reduce their risk of neural tube birth defect (NTD)-affected pregnancies. Interest now focuses on assessing the effects of fortification on risk of NTDs and on folate intake relative to homocysteine (Hcy) concentrations and risk of vascular disease, although a causal relationship between the latter two has not been demonstrated. Increased serum folate levels were first reported in 1999. Data from the Framingham Offspring Study cohort showed increased mean serum folate in middle-aged and older adults; additionally, the prevalence of high Hcy concentrations had decreased by approximately 50% in subjects examined before (1995-1996) and after (1997-1998) fortification. Another analyses of samples collected between 1994 and 1999 identified a trend of increasing serum folate values from 1996 onward with values in 1998 160% of those measured in 1996. Comparisons between 1988-1994 National Health and Nutrition Examination Survey (NHANES) III data and 1999 NHANES showed increased serum and erythrocyte folate concentrations among childbearing-aged women. While recent data show improved folate status in a short period of time, much about long-term effects of the fortification program remains unknown. Interest in the effects of increased folate intakes on risk of NTDs or vascular disease needs to be balanced against concerns about masking the anemia of vitamin B-12 deficiency and the general lack of data about safety of continuous high intakes. Careful monitoring over time is necessary to determine that the program functions as intended.

Iron and Folate in Fortified Cereals

Background: Fortification of cereal-grain products was introduced in 1941 when iron and three vitamins were added to flour and bread. Ready-to-eat cereals were fortified at about the same time. These fortifications have contributed to increased dietary iron intake and reductions in iron deficiency anemia in the US. In 1996, FDA finalized rules for fortification of specific enriched cereal-grain products with folic acid. This measure was instituted to increase the folate intakes of women of child-bearing age and thereby reduce the risk of having a pregnancy affected with a neural tube birth defect. However, with recent increases in fortification, public health officials in the US are concerned that excess intake of specific nutrients such as iron and folic acid may result in toxic manifestations.Objective: Our objective was to measure iron and total folate content in breakfast cereals and compare assay to label values for % Daily Value. We also determined by weight the amount of a ready-to-eat breakfast cereal adults would eat and compared this to the labeled serving size, for which the reference amount for this cereal per eating occasion was 1 cup or 30 g.Design: Twenty-nine breakfast cereals were analyzed for iron content using the bathophenanthroline reaction. Twenty-eight cereals were analyzed for total folate, utilizing a microbiological assay with tri-enzyme digestion. Serving size quantities were estimated in seventy-two adults who regularly ate breakfast cereal and were asked to fill a 16 or 22 cm round bowl with the amount of cereal that they would consume for breakfast.Results: When the labeled value was compared to the assayed value for iron content 21 of the 29 breakfast cereals were 120% or more of the label value and 8 cereals were 150% or more of the label value. Overall, analyzed values for iron ranged from 80% to 190% of label values. Analyzed values for folate ranged from 98% to 320% of label values. For 14 of 28 cereals, analyzed values exceeded label declarations by more than 150%. Bran-containing cereals contained the highest amounts of folate relative to their label declarations. The median analyzed serving size for the breakfast cereal was 47 g for females, 61 g for males with a combined median of 56 g as compared to the label value of 30 g.Conclusions: Analyzed values of iron and folic acid in breakfast cereals were considerably higher than labeled values. For adults, the amount of cereal actually consumed was approximately 200% of the labeled serving size. When the quantity of cereal consumed is more than the labeled serving size and when the levels of iron and folate are higher than declared, the intake of both will be significantly greater than the labeled values. It will be important to continue monitoring serum ferritin and folate levels in NHANES IV, since daily consumption of breakfast cereals may contribute to excessive intakes of iron and folate.

Total folate in enriched cereal-grain products in the United States following fortification

The full compliance date for mandatory folic acid fortification of enriched cereal-grain products in the United States was 1 January, 1998. There is currently a great interest in determining the effectiveness of this measure, which was instituted to increase the folate intakes of women of child-bearing age to reduce their risk of having a pregnancy affected by a neural tube birth defect. We surveyed 83 enriched cereal-grain products that are required to be fortified with folic acid under the new regulations and an additional 79 foods that contain enriched cereal-grain ingredients or that are currently fortified with folic acid. Products were collected and analyzed between February 1998 and April 1999. Total folate was determined by microbiological assay using a tri-enzyme digestion. We compared analyzed values for total folate with amounts required by Federal regulations and/or with label declarations of folate content. For many enriched cereal-grain products, there were significant differences between amounts of folate found on analysis and amounts required by Federal regulations. In part because of this, label declarations of folate content were also in error. The high values found in some enriched cereal-grain products may represent manufacturers' averages as well as the presence of higher-than-expected levels of endogenous folates. These results indicate that reliable food composition databases cannot be developed without extensive new data on the actual concentrations of folate in recently fortified enriched cereal-grain products as well as in products containing enriched cereal-grain ingredients. Reliance on older data bases or on compositional information that has a weak analytical underpinning will lead to unsound estimates of folate intake, and hence, of the potential impact of the new fortification program.

Use of a microbiological assay with tri-enzyme extraction for measurement of pre-fortification levels of folates in enriched cereal-grain products

January 1, 1998 was the effective date for PDA regulations that mandated the fortification in the USA of a wide range of enriched cereal-grain products with folic acid at levels specified in federal regulations. Because data on prefortification levels of folate in such products are limited, we measured folate in 56 enriched foods, including enriched breads and rolls, flours, corn grits and meals, rices, and macaroni and noodle products. Folate was measured by a modification of the Association of Official Analytical Chemists' microbiological method 992.05 using Lactobacillus casei. Foods were composited, suspended in 0. 1 m phosphate buffer containing 1% ascorbic acid (pH 7.8), autoclaved and cooled. Chicken pancreas conjugase was added and the suspensions were incubated for 16h at 37 °C. Values for folate in enriched products were (μg/lOOg): bread and rolls, 24–40; flours, 19–24; corn grits and meals, 22–32; macaroni and noodle products, 27–42; rice, 19–32. Because the single-enzyme method is usually insufficient to liberate food-bound folates, suspensions of foods were also incubated with α-amylase and conjugase followed by treatment with protease to determine the effects of the tri-enzyme digestion on release of folates. For many foods, total folate was 20–30% higher after the tri-enzyme digestion than after incubation with conjugase alone. The modifications of AOAC method 992.05 described here provide a microbiological assay method for the determination of folates in cereal-grain products that may be appropriate for collaborative testing.