June 21, 2019
Americans have not appreciably changed their consumption of processed meats during the last 18 years, despite growing evidence linking luncheon meats, sausage, hot dogs, bacon, and other processed meats to illnesses such as colorectal cancer, an analysis of survey data has found. Fish and shellfish consumption also did not change: fewer than 15% of US adults met the recommended intake of 8 ounces per week.
During the same period, poultry consumption increased whereas consumption of unprocessed red meat — including beef, pork, and lamb — did show a downward trend. One fourth of American adults still eat more than the recommended weekly limit for red meat of 500 grams, or fewer than three servings, however.
All in all, "nearly one-quarter (range = 23.4% to 24.5%) of the total meat and poultry consumed by US adults in 1999–2016 was processed meat," with consumption of processed meat exceeding that of fish and shellfish at every time point examined, the researchers write.
The findings suggest that public health experts should do more to raise the public's awareness of the health risks associated with processed and red meat, and the benefits of eating more fish, the authors say.
Luxian Zeng, MD, Friedman School of Nutrition Science and Policy, Tufts University, Boston, Massachusetts; Mengyuan Ruan, MS, Tufts University School of Medicine, Boston; and colleagues report their findings in an article published today in Journal of the Academy of Nutrition and Dietetics.
For example, the 2015–2020 Dietary Guidelines for Americans do not state that processed meat is a carcinogen, although the guidelines do cite a low intake of processed meat as one characteristic of a healthy diet pattern, explain the authors.
Because the survey also showed that processed meats were purchased mostly in stores and fast-food restaurants, "future policies may prioritize these as primary sites of intervention," they add.
Messages about the drawbacks of unprocessed red meat appear to have been more effective, they write. Noting that per-capita consumption of red meat decreased by 13% from 1999 to 2016, the authors explain that "in a recent survey of US adults, more than half of the participants who reported eating less meat now compared to 3 years ago ranked cost and health as the two primary reasons for reducing meat consumption." Per-capita poultry consumption increased by 14.1% during the same period.
Similarly, economics may play a role in the generally low consumption of seafood, the authors point out, as well as "lack of awareness of its health benefits, and concerns about mercury contamination in certain fish, although the scientific evidence suggests that the benefits of fish intake exceed the potential risks."
The findings come from the National Health and Nutrition Examination Survey, a program of studies designed to provide a representative sample of the health and nutritional status of adults and children in the United States. This study included data on 43,995 adults aged 20 years or older who had completed at least one 24-hour diet recall interview during the nine 2-year survey cycles from 1999 to 2000 through 2015 to 2016.
The interviews included questions about every food and beverage each participant had consumed the previous day, with measuring guides used to help estimate portion size. The participants also were asked where they purchased the meal or most of the ingredients for it.
Changes in dietary intake were then calculated as the differences in mean intake between the earliest cycle, covering the years 1999 to 2000, and the latest, for the years 2015 to 2016, included in the survey.
Mean consumption of processed meat was 182 grams/week (g/wk) in 1999 to 2000 and 187 g/wk in 2015 to 2016 (mean change, 4.22 g/wk; 95% confidence interval [CI],18.4 to 26.8 g/wk; P for trend = .95). For unprocessed red meat, mean consumption went from 340 g/wk in 1999 to 2000 to 284 g/wk in 2015 to 2016 (mean change, –56.7 g/wk; 95% CI, –88.0 to –25.4 g/wk; P for trend < .001).
Poultry consumption increased during the study period, from a mean of 256 g/wk in 1999 to 2000 to 303 g/wk in 2015 to 2016 (mean change, 47.0 g/wk; 95% CI, 12.0 to 82.0 g/wk; P for trend < .001). Fish and shellfish consumption, however, remained virtually unchanged, at a mean of 115 g/wk in 1999 to 2000 and 116 g/wk in 2015 to 2016 (mean change, 1.55 g/wk; 95% CI, –22.5 to 25.6 g/wk; P for trend = .14).
Stores accounted for 73.2% of processed meat purchases as well as 61.6% of unprocessed red meat, 61.5% of poultry, and 59.7% of fish and shellfish purchases. Fast-food restaurants accounted for 19.2% of total poultry consumption, 16.4% of unprocessed red meat consumption, and 12.5% of processed meat consumption.
As for fish and shellfish consumption, fast-food restaurants accounted for less than 10%, whereas full-service restaurants accounted for 23%.
Numerous factors can influence food choices, Zhang says in a news release about the study. But "the lack of widespread awareness of health risks associated with processed meat may have contributed to the lack of consumption change in the past 18 years."
"Our findings support further actions to increase the public awareness of the health risks associated with high processed meat consumption in the US," Zhang concludes.
One author reports research funding from the National Institutes of Health and the Gates Foundation; personal fees from GOED, DSM, Nutrition Impact, Pollock Communications, Bunge, Indigo Agriculture, Amarin, Acasti Pharma, and America’s Test Kitchen; scientific advisory board, Omada Health, Elysium Health, and DayTwo; and chapter royalties from UpToDate, all outside of the submitted work. The remaining authors have disclosed no relevant financial relationships.