Scholarly article on topic 'Sodium Trends in Selected U.S. Total Diet Study Foods, 2003-2011'

Sodium Trends in Selected U.S. Total Diet Study Foods, 2003-2011 Academic research paper on "Agriculture, forestry, and fisheries"

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Abstract of research paper on Agriculture, forestry, and fisheries, author of scientific article — Stephanie Briguglio, Stuart Chirtel, Judith Spungen, P. Isaac Rabbani, Dana Hoffman-Pennesi, et al.

Abstract Objective Characterize trends in sodium concentrations in the general categories of foods analyzed in the U.S. FDA Total Diet Study (TDS) program from 2003 through 2011. Methods: Trends were assessed for sodium concentrations in a small convenience sample of TDS foods from 2003 to 2011 using simple linear regression with the SAS regression procedure, focusing on sodium concentrations in foods in USDA's sentinel food categories. Results: Levels of sodium in various TDS foods varied over time. Overall, 75 TDS foods did not have statistically significant linear changes in sodium content during that time, and 23 TDS foods did. Certain sentinel foods such as ramen-style noodles showed gradually increasing sodium content from 2003 through 2011. Significance: Over three quarters of foods show no statistically significant linear changes over time. Although a number of selected foods had a statistically significant decline, a limitation to this study is that specific brands of TDS foods were not necessarily the same for each period. The results suggest that some sodium reduction has been occurring in some foods and supports the idea that commercially viable reductions are possible. Such reductions in the sodium content of foods could have large public health implications—rates of hypertension and related health consequences would likely decline—thus saving thousands of lives and billions of dollars each year.

Academic research paper on topic "Sodium Trends in Selected U.S. Total Diet Study Foods, 2003-2011"

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Procedia Food Science 4 (2015) 27 - 38

38th National Nutrient Databank Conference

Sodium Trends in Selected U.S. Total Diet Study Foods, 2003-2011

Stephanie Briguglio, MPH CPHa*; Stuart Chirtel, MSa; Judith Spungen, MS RDa; P. Isaac Rabbani, Ph.D. FACN CNSat; Dana Hoffman-Pennesi, MSa; Mark Wirtz, BSa

aCenter for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD 20740, USA

Abstract

Objective: Characterize trends in sodium concentrations in the general categories of foods analyzed in the U.S. FDA Total Diet Study (TDS) program from 2003 through 2011. Methods: Trends were assessed for sodium concentrations in a small convenience sample of TDS foods from 2003 to 2011 using simple linear regression with the SAS regression procedure, focusing on sodium concentrations in foods in USDA's sentinel food categories. Results: Levels of sodium in various TDS foods varied over time. Overall, 75 TDS foods did not have statistically significant linear changes in sodium content during that time, and 23 TDS foods did. Certain sentinel foods such as ramen-style noodles showed gradually increasing sodium content from 2003 through 2011. Significance: Over three quarters of foods show no statistically significant linear changes over time. Although a number of selected foods had a statistically significant decline, a limitation to this study is that specific brands of TDS foods were not necessarily the same for each period. The results suggest that some sodium reduction has been occurring in some foods and supports the idea that commercially viable reductions are possible. Such reductions in the sodium content of foods could have large public health implications—rates of hypertension and related health consequences would likely decline—thus saving thousands of lives and billions of dollars each year.

PublishedbyElsevier Ltd.Thisisanopenaccess article under the CC BY-NC-ND license (http://creativecommons.Org/licenses/by-nc-nd/4.0/).

Peer-review under responsibility of the National Nutrient Databank Steering Committee Keywords: Total diet study; sodium

1. Introduction

* Corresponding author. Tel.: +1-240-402-2195 E-mail address: Stephanie.briguglio@fda.hhs.gov t Retired October 2014

2211-601X Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Peer-review under responsibility of the National Nutrient Databank Steering Committee doi: 10.1016/j.profoo.2015.06.006

Excessive sodium intake can lead to hypertension1. Hypertension accounts for 62% of cerebrovascular disease and 49% of ischemic heart disease2. Sodium is ubiquitous in foods. Over three-quarters of sodium consumed in the U.S. is from processed or restaurant foods. Over 40% of the sodium Americans consume comes from ten types of foods: breads and rolls, deli and cured meats, pizza, fresh and processed poultry, soups, sandwiches, cheese, mixed pasta dishes, mixed meat dishes, and snacks such as potato chips, popcorn, and crackers3. Thus, there is a great need for restaurants and food manufacturers to lower sodium content in their foods in order to curb the public health impact of excess sodium consumption. A large number of food and restaurant companies have made commitments to reduce the sodium content of their products and there is some evidence of success in many products. Additionally, several recent sodium reduction initiatives are underway such as the National Salt Reduction Initiative (NSRI), a public-private New York City Health Department partnership consisting of over 90 participating packaged food companies and restaurants that have pledged to meet relevant targets for salt content in their overall sales of given food categories4. Britain's Food Standards Agency set salt-reduction targets in different food categories over a decade ago and encouraged companies to meet these targets over time. England saw a reduction in sodium consumption by 15% from 2001 and 2011, and has also seen a decline in stroke and heart disease deaths that may be attributed to a decline in blood pressure5.

The TDS is an ongoing U.S. Food and Drug Administration (FDA) program initiated in 1961 that monitors levels of various contaminants and nutrients in over 280 foods identified as being of importance in the American diet. TDS collects each of these foods quarterly from one of four geographical regions of the U.S.6. Together, the foods collected in each sampling period are referred to as a "market basket." For each quarterly market basket, FDA purchases foods in each of three cities within the region and sends the food samples to FDA's Kansas City District Laboratory. Staff at a nearby institutional kitchen prepare the foods according to recipes or as per package directions, take samples, and make composites of the prepared food samples from the three cities. FDA's Kansas City District Laboratory analyzes the food composites to determine concentrations of mineral nutrients, toxic elements, and pesticides7. The study provides a snapshot in time of the nutrient and contaminant content in many widely consumed foods, including fresh and canned fruits and vegetables, grains, dishes prepared for the study, restaurant and processed foods, among others. The purpose of the present study was to characterize trends in sodium concentrations in the general categories of foods analyzed in the TDS program over time; because the brands included in composites may vary between market baskets, TDS data cannot be used to characterize trends in composition of specific brands. The TDS first analyzed products for sodium in 1977, and then quarterly beginning in 1980. The list of foods analyzed changed significantly in 2003, and therefore only foods beginning in 2003 were examined for the purposes of this paper.

2. Methods

Trends in the sodium content in the selected U.S. TDS foods were examined using SAS V9.38. Only the 251 TDS

foods that were continually analyzed from 2003 through 2011 were considered for inclusion in the analysis.

In order to take a closer look at foods of particular interest due to their contribution to population sodium intake,

individual TDS foods were mapped to a list of sentinel food categories developed by multiple agencies including the

USDA's Agricultural Research Service (ARS)9. The sentinel foods include "mainly commercially packaged and

restaurant foods, selected based on evaluation of their sodium content, frequency of consumption, and potential for

possible reduction in sodium content of the food"10. It is hoped that foods falling within these sentinel categories will serve as primary indicators of change in sodium content of foods.

Of the 251 TDS foods continuously analyzed from 2003 through 2011, 98 were identified as aligning with one of the sentinel categories for sodium monitoring. The concentrations of sodium (mg/100g) of these 98 foods were regressed on year for each food item using simple linear regression with SAS Proc Reg8. Each TDS food trend was based on 36 results, since each food was sampled quarterly over nine years; each sample is a composite of 3 subsamples.

Sentinel food category

Example of foods

Mixed dishes Grain products

Vegetable dishes, beans

Chicken, seafood, pork

Cured/processed meats

Fast food sandwiches Mexican type dishes Cheeses

Soups/broths

Savory snacks/crackers Cakes, cookies, pastry Nuts, peanut butter

Pizza; pasta-based dishes; chili; egg roll

Bread; rolls; tortilla; bagel; taco shell; ready-to-eat cereals; pancakes; biscuit

Canned corn; French fries/frozen and fast food; potato salad

Nuggets/frozen and fast food; rotisserie; breaded fish filet; fried shrimp; pork chops

Deli ham/turkey; bologna; bacon; hot dog/corndog; salami

Double cheeseburger; hamburger Beef taco; bean burrito

Cheddar; fried mozzarella sticks; nacho cheese dip; cottage cheese

Tomato soup; ramen noodles soup; chicken noodle soup/broth

Pretzels; potato chips; popcorn; tortilla chips Doughnut; cinnamon bun; chocolate chip cookie Peanuts; peanut butter

Figure 1. U.S. TDS foods examined for statistically significant linear trends (p<0.05), 2003-2011

TDS Foods Analyzed

2003-2011

98 TDS Foods

that Align with

Sentinel Categories

23 TDS Foods >

with Trends p<0.05

that Align with

Sentinel Categories j

Processed /Cured Meats

Grain Products

Vegetables*

.' 0/5 ) !

I Chicken/ I I

' Seafood/ I j

I Pork 1 I

V _ _ _ _ X V.

/ \ t~

I 0/5 j J

I Cheeses ! g

V____y

Dishes

Nuts/ Peanut Sutter

Mexican-

type Dishes

Savory snacks/ crackers

Fast Food ;

Sand- :

Wiehes I

Cakes/ Cookies/ Pastry

TDS foods that align with sentinel food categories with statistically significant trends found (p<0.05) out of total number of TDS foods aligning with sentinel categories

TDS foods that align with sentinel food

categories with no statistically significant trends found (p<0.05) out of total number of TDS foods aligning with sentinel categories

3. Results

From 2003 to 2011, 251 TDS foods were analyzed quarterly for sodium concentration. Of the 98 TDS foods identified as aligning with one of the sentinel categories for sodium monitoring, 77% were found to have no statistically significant linear changes in sodium content over the period. . The 23 TDS foods (23%) that were found to have statistically significant (p<0.05) linear trends in sodium concentration from 2003 to 2011 are presented in Table 2. The percent difference in mean sodium (mg/100g) between 2003 and 2011 is also presented in Table 2. Of these 23 foods, 19 were found to have statistically significant decreasing trends and four were found to have statistically significant increasing trends. Of the twelve sentinel food categories identified in Figure 1, only seven categories included TDS foods with statistically significant trends.

Table 2. TDS Foods with Significant Trends (p<0.05) in Sodium: 2003-2011*

No. Food Description

75 Crisped rice cereal

77 Oat ring cereal

239 Luncheon meat (ham)

372 Popcorn, microwave, butter-

flavored

119 Tomato sauce, plain, bottled

74 Raisin bran cereal

248 Bread, multi-grain

76 Granola w/ raisins

344 Pancakes, frozen, heated

261 Tomato juice, bottled

252 Crackers, butter-type

366 Chicken filet (broiled)

sandwich on bun, fast-food

131 Beets, canned

55 Corn, canned

155 Soup, chicken noodle, canned,

condensed, prepared w/ water

156 Soup, tomato, canned,

condensed, prepared w/ water

185 Apple pie, fresh/frozen

65 Muffin, fruit or plain

58 Bread, white, enriched

278 Egg, cheese, and ham on

English muffin, fast-food

370 Granola bar, w/ raisins

30 Salami, luncheon-meat type

(not hard)

367 Soup, Oriental noodles

(ramen noodles), prepared w/

Slope of 95% Na Confidence

(mg/100g) p-value Interval

-30.8 <0.0001 -41.6

-30.1 <0.0001 -39.5

-19.7 0.037 -38.2

-17.4 0.008 -30.0

-15.0 0.008 -25.8

-14.1 0.0004 -21.4

-13.0 0.002 -20.9

-12.8 0.021 -23.6

-12.0 0.001 -19.0

-11.9 0.001 -18.2

-11.8 0.032 -22.5

-9.4 0.022 -17.4

-9.0 0.002 -14.4

-8.5 0.036 -16.5

-8.0 0.027 -15.0

-7.3 0.004 -11.9

-7.2 0.004 -11.94

-5.9 0.014 -10.5

-5.4 0.031 -10.2

5.9 0.006 1.8

7.7 0.004 2.6

25.9 0.022 3.9

29.4 0.001 13.7

Upper 2003 2011

95% mean** mean**

Confidence result result

Interval (mg/100g) (mg/100g)

-20.0 927 655

-20.6 857 509

-1.3 1278 952

-4.8 846 674

-4.2 598 463

-6.8 592 477

-5.1 484 414

-2.1 200 104

-5.0 600 459

-5.5 338 219

-1.1 850 780

-1.5 528 461

-3.5 204 117

-0.6 235 138

-0.9 435 320

-2.6 288 249

-2.5 279 239

-1.3 363 322

-0.5 535 499

10.0 593 646

12.7 260 261

47.8 1188 1365 45.2 318 650

Difference

2003-2011

-29.3 -40.6 -25.5 -20.3 -22.6 -19.3 -14.6 -48.3 -23.6 -35.3 -8.3 -12.7 -42.8 -41.1 -26.5 -13.8 -14.2 -11.1 -6.8 8.9 0.5 14.9 104.8

*Of 98 foods in TDS **n=36 results per food

study aligning with sentinel food categories (quarterly sample collections over nine years)

Fit plots of selected foods found to have statistically significant linear trends (p<0.05) of sodium concentration

(mg/100g), 2003-2011 are shown in Figures 2-7

Figure 2. TDS food no. 75, Crisped rice cereal

Fit Plot for sodium

2004 2006 2008 2010

Fiscal Year

-Fit □ 95% Confidence Limits 95% Prediction Limits

4. Discussion

Other governments have had success with programs designed to lower the sodium content of foods in their countries. At least one of these initiatives has shown that gradual industry reductions in the sodium content of packaged and restaurant foods5, along with educational messages focused on reducing sodium intake, show promise as methods for increasing consumer control over intake and making recommended intake levels and their associated improvements in public health more attainable. Taste, as well as technological feasibility, is a consideration when reducing sodium content in foods.

There are limitations to the conclusions that can be drawn from this analysis due to the methodology inherent to the TDS. The TDS provides a limited look into the food supply and further analysis is warranted. The TDS does not collect brand information and the protocol was not designed to be sensitive to manufacturer variation in food formulation over time. Specific brands of TDS foods analyzed over time were not necessarily the same for each period. While some TDS foods show trends, this study is not representative of the entire food supply. However, the analysis presented here suggests that some sodium reduction has been occurring in some foods and supports the idea that commercially viable reductions are possible.

Proposed next steps include continuing the suggested industry progress to further reduce the sodium content of foods, and refining and coordinating various complimentary sodium content monitoring projects across agencies to ensure a system that supports comprehensive, up-to-date monitoring of sodium levels in the U. S. food supply as a critical component of understanding sodium intake in the U.S. population. FDA continues to monitor other food component trends and the data from the TDS program can be utilized for these determinations.

References

[1] Institute of Medicine. Dietary reference intakes for water, potassium, sodium chloride, and sulfate. Washington, DC: National Academies

Press; 2004.

[2] World Health Organization (WHO). World Health Report 2002: Reducing risks, promoting healthy life; 2002. Available from:

www.who.int/whr/2002

[3] Centers for Disease Control and Prevention (CDC). (2012). Vital signs: food categories contributing the most to sodium consumption—

United States, 2007-2008. MMWR 2012. 2012;61, 1-7.

[4] The New York City Department of Health and Mental Hygiene. National Salt Reduction Initiative; 2014. Available from:

http://www.nyc.gov/html/doh/html/diseases/salt.shtml

[5] He FJ, Pombo-Rodrigues S, & MacGregor GA. Salt reduction in England from 2003 to 2011: its relationship to blood pressure, stroke and

ischaemic heart disease mortality. BMJ Open. 2014;4(e004549). Available from: http://bmjopen.bmj.com/content/4/4/e004549.full

[6] U.S. Food and Drug Administration (FDA). Total Diet Study; 2013. Available from:

http://www.fda.gov/Food/FoodScienceResearch/TotalDietStudy/default.htm

[7] Pehrsson, PR, Patterson, KY, Spungen, JH, Wirtz, MS, Andrews, KW, et al. Iodine in food and dietary supplement composition databases.

American Journal of Clinical Nutrition. In press.

[8] SAS Institute Inc. 2012. Base SAS®9.3 Procedures Guide, Second Edition. Cary,NC: SAS Institute Inc.

[9] Moshfegh, AJ. Food Surveys Research Group. Beltsville Human Nutrition Research Center. Agricultural Research Service, USDA.

Methodological considerations in assessing dietary sodium intake in the population using What We Eat in America, NHANES; 2012 December. IOM Workshop on Perspectives on Dietary Sodium and Health. Washington, DC. Available from: http://www.iom.edu/~/media/Files/Activity%20Files/Nutrition/ConsequencesSodiumReduction/2012-DEC-04/Presentations/05_Alana%20Moshfegh.pdf

[10] Holden JM, Pehrsson PR, Nickle M, Haytowitz DB, Exler J, Showell B, et al. USDA monitors levels of added sodium in commercial

packaged and restaurant foods. Procedia Food Science. 2013;2:60-67.