Trending Topics pieces (Article Analyses, Evidence Clips and Other Topics) are published in timely response to recent media and journal articles, position statements, clinical guidelines, etc. Since they are based on the most recent evidence/publications, they may not be consistent with PEN evidence in other PEN content areas. As soon as possible, when this occurs, the PEN content will be reviewed and updated as needed.
COVID-19 Trials and Research We Are Watching
Vitamin C Trials
A randomized control trial published in JAMA showing a lack of effectiveness of intravenous vitamin C, hydrocortisone and thiamine as compared to hydrocortisone alone in a quicker resolution of septic shock suggests that intravenous vitamin C is not likely to be effective for COVID-19 treatment.
A trial from the US National Library of Medicine ClinicalTrials.gov: Vitamin C Infusion for the Treatment of Severe 2019-nCoV Infected Pneumonia is underway (estimated completion September 2020). This trial is designed to provide more definitive answers about the effectiveness of intravenous vitamin C for COVID-19.
A New Site - LitCOVID
LitCOVID is new from PUBMED. It is a site to help scientists keep track of COVID-19 evidence publications.
*Word of Caution from PEN Evidence Analysts: Please keep in mind that these papers are being rushed to publication as the information is wanted ASAP. Some of these papers are not peer reviewed. While peer review is not a perfect process by any means, it does allow an unbiased review of the work by someone external to the research group.
SARS-CoV-2 Virus Stability and Disinfecting
Two recent studies have emerged on the persistence of the coronavirus on various surfaces (1,2). Using an in vitro study, Van Doremalen et al. examined how long SARS-CoV-2 virus (i.e. the virus that causes COVID-19*) remained viable on four surfaces (cardboard, plastic, stainless steel and copper) for varying lengths of time (1). At room temperature and 40% humidity, viable SARS-CoV-2 viruses were detectable up to 24 hours on cardboard and up to 72 hours on stainless steel and plastic. The virus was not viable after four hours on copper.
Kampf et al. reported a review on coronavirus persistence on surfaces and materials (2). While this second study examined coronaviruses, it did not specifically study the SARS-CoV-2 virus; the authors suggest that they expect the persistence and inactivation of this new coronavirus are likely similar. They found that coronaviruses can remain potentially infectious from two hours up to nine days on various materials. At higher air temperatures of 30 to 40 °C, persistence was reduced compared to room temperatures. The studied viruses were stable (≥28 days) at refrigerator temperature, 4 °C. Humidity influenced persistence, as coronaviruses were less stable at 30% relative humidity compared to 50% relative humidity. The researchers also found that biocidal agents including 62-71% ethanol, 0.5% hydrogen peroxide or 0.2% sodium hypochlorite (bleach - preparation instructions below) used for disinfecting inactivated coronaviruses within one minute. Other biocidal agents were noted to be less effective.
Various organizations have now recommended guidelines based on the results of the first study. These include:
- Wash your hands thoroughly with soap and water for 20 seconds before and after preparing and eating food, using the washroom, after sneezing or coughing (3). Although the risk is low, if you are concerned or if you or someone in the household is of high risk, wash your hands after handling anything that might be contaminated such as cardboard, plastic and stainless steel (4).
- Disinfect hard surfaces daily including high touch areas such door handles, light switches, counter tops, tables, keyboards, toys, phones and TV remotes using ER-approved disinfectant (3).
- Refer to Health Canada’s Hard Surface Disinfectants and Hand Sanitizers (COVID-19) for instructions and for a list of effective disinfectants. Be sure to read manufacturers’ directions on the labels of the disinfectant cleaning product as many of these need to remain in contact with the surface for a period of time (e.g. 30 seconds) to be effective (e.g. do not just spray on and wipe off) (5).
- As these products are currently hard to find because of the COVID-19 pandemic, a solution of diluted bleach can also be used as per instructions on the label of the bleach container. For 5% sodium hypochlorite bleach (the usual concentration sold in stores) use 5 mL (1 tsp) per 250 mL (1 cup) of water or 20 mL (4 tsp) per 1 litre (4 cups) of water to make a 0.2% solution (5).
- Cleaning products remove germs and dirt, lowering their numbers and reducing the risk of spreading infections (5). Products with disinfectants kill germs.
*Note: SARS-CoV-2 is the name of the virus. COVID-19 is the disease the virus causes.
- van Doremalen N, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, et al. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med. 2020 Mar 17. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/?term=32182409
- Kampf G, Todt D, Pfaender S, Steinmann E. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. J Hosp Infect. 2020 Mar;104(3):246-51. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/?term=32035997
- Health Canada. Coronavirus Disease (COVID-19): prevention and risks. 2020 Apr 1. Available from: https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus-infection/prevention-risks.html?topic=tilelink
- Harvard T.H. Chan. School of Public Health. Food Safety, nutrition, and wellness during COVID-19. 2020 Mar 25. Available from https://www.hsph.harvard.edu/nutritionsource/2020/03/25/food-safety-nutrition-and-wellness-during-covid-19/
- Health Canada. Hard surface disinfectants and hand sanitizers (COVID-19). 2020 Mar 30. Available from https://www.canada.ca/en/health-canada/services/drugs-health-products/disinfectants/covid-19.html
Immunity, Nutrition and COVID-19
Have you been asked questions regarding the COVID-19 virus, immunity and nutrition? The following resources may help you answer them, see:
The novel coronavirus is new and evidence to support specific dietetic recommendations is not yet available in the scientific literature. The bottom line is that a healthy diet rich in fruit and vegetables, protein foods and whole grains is important for a strong immune system as are other healthy lifestyle habits (e.g exercise, not smoking, adequate sleep, managing stress etc). There is no one food or nutrient, supplement or herb that will protect you from the COVID-19 virus. The WHO has stated that there is no evidence that the consumption of garlic will prevent COVID-19. For this and other myth busters see WHO's advice for the public: myth busters. For more information about how to protect yourself and others, please follow the advice of your health authorities.
New Study - Dairy and Breast Cancer Risk
Many news websites, including CTV (1), reported on a study (2) that looked at soy and dairy consumption and breast cancer risk. The study, which is part of the Adventist Health Study-2 (3), followed 52,795 North American women (mean age 57.1 years; free of cancer at study onset) for 7.9 years (between 2002 to 2007) who had a high average soy consumption. Self-reported food frequency questionnaires and 24-hour recalls were used to assess dietary intakes at entry into the study.
There were 1,057 new breast cancer cases found via North American cancer registries during the study time (2). Intakes of dairy calories and dairy milk were associated with a slightly greater risk of breast cancer independent of soy intake (hazard ratio (HR) 1.22; 95% confidence interval (CI), 1.05 to 1.40 and HR 1.50; 95%CI, 1.22 to1.84, respectively, comparing 90th to 10th percentiles of intakes), while there were no clear associations found between soy products and breast cancer. Fat level of milks and the consumption of cheese and yogurt showed no associations with cancer. A decreased risk of breast cancer was associated when substituting median intakes of soy milk for dairy milk (HR, 0.68; 95%CI, 0.55 to 0.85). The authors concluded that as milk intake increased, so did the risk of breast cancer, when adjusted for soy intake.
An important concern about this study is that the news headline stated “One cup of milk per day associated with up to 50 per cent increase in breast cancer risk: study” (1), which is misleading since it focused on the relative risks of a rare outcome. Looking at the absolute risks (which is a better way to report these results since the cancer was rare), the risk of cancer in this study was 2% (2 cases per 100 women) and 3% (3 cases per 100 women) among women who drank milk (HR=1.50). The absolute risk difference is 1%, so the headline stating 50% increase is reporting a statistic that suggests a big risk. Reporting the absolute risk difference (1%) gives more relevant information on the actual risk for an individual (4).
When analyzing this study there are a few limitations that should be considered. This is an observational study, so cause and effect cannot be established. Dietary intakes were self-reported and only measured once at baseline, so there is room for errors and omissions. The study did not adjust for social determinants of health or quantities of moderate or total physical activity, quantity of alcohol consumed or amounts smoked (the authors only controlled for vigorous activity, duration of alcohol use and smoking ever or never), so some or all of these variables could confound the results.
These results contrast with findings reported by the American Institute for Cancer Research (5) and an overview of systematic reviews (6), which found no consistent associations between dairy products or milk intake and the risk of postmenopausal breast cancer and actually observed a reduced risk of premenopausal breast cancer.
The authors of the study comment that dairy milk does have positive nutritional qualities and suggest that more research is needed to understand whether there is a true link between dairy intake, or other closely-related unidentified factor(s), and breast cancer risk. Until further research is available, dietitians can continue to review healthy lifestyle behaviours with clients including eating a balanced and varied diet that includes lots of vegetables, fruit and whole grain foods; engaging in regular physical activity; and avoiding smoking. Refer to the PEN client handout: Cancer Prevention Eating Guidelines.
- Bogart N. One cup of milk per day associated with up to 50 percent increase in breast cancer risk: study. CTV News. February 25, 2020. [cited 2020 Feb 27]. Available from: https://www.ctvnews.ca/health/one-cup-of-milk-per-day-associated-with-up-to-50-per-cent-increase-in-breast-cancer-risk-study-1.4826979
- Fraser GE, Jaceldo-Sielg K, Orlich M, Mashak A, Sirirat R, Knutsen S. Dairy, soy, and risk of breast cancer: those confounded milks. Int J Epidemiol. 2020 Feb; pii: dyaa007. doi: 10.1093/ije/dyaa007. Available from: https://www.ncbi.nlm.nih.gov/pubmed/32095830
- Loma Linda University Health. Adventist Health Study-2. 2020. [cited 2020 Feb 27]. Available from: https://adventisthealthstudy.org/
- Noordzij M, van Diepen M, Caskey FC, Jager JK. Relative risk versus absolute risk: one cannot be interpreted without the other. Nephrol Dial Transplant. 2017 Apr;32(suppl 2): :ii13-ii18. doi: 10.1093/ndt/gfw465. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/?term=28339913
- American Institute for Cancer Research. Key findings. Diet, nutrition, physical activity and breast cancer. Revised 2018. Available from: https://www.aicr.org/research/the-continuous-update-project/breast-cancer/
- Jeyaraman M, Abou-Setta, Grane L, Farshidfar F, Copstein L, et al. Dairy product consumption and development of cancer: an overview of reviews. BMJ Open. 2019 Jan;9(1):e023625. doi: 10.1136/bmjopen-2018-023625. Available from: https://www.ncbi.nlm.nih.gov/pubmed/30782711
Addressing Stigma: Towards a More Inclusive Health System
The Chief Public Health Officer’s Report on the State of Public Health in Canada in 2019 includes information about trends and the need to provide trusted, evidence-based information to Canadians. The report summarizes Canadian health status in terms of mental illness, substance use, tuberculosis, HIV, obesity, vaccine coverage, sexually transmitted infections, youth vaping, youth cigarette smoking and the opioid crisis. The report also addresses stigma that affects health including stigma experienced by First Nations, Inuit, and Métis peoples, African, Caribbean and Black Canadians, seniors and members of the LGBTQ2+ people.
The report was developed based on stakeholder engagement and evidence reviews conducted of social and health science databases. Interviews and discussions involved >90 leaders from across Canada, which included individuals with lived experience, policy-makers, researchers, clinicians and administrators. It presents a new Action Framework for Building an Inclusive Health System to explore how stigma can be addressed.
See Additional Content: Weight Stigma Background.
Vitamin D Update: Supplementation and Pregnancy and Perinatal Outcomes and 25-hyroxy-vitamin D as a Marker for Nutrient Deficiency and Sufficiency
Vitamin D has been a very active area of research in recent decades. Not only have there been numerous research studies published, there have also been numerous systematic reviews published summarizing these studies. Recently, researchers in Alberta, Canada undertook a systematic review of the systematic reviews that investigated the importance of vitamin D in pregnancy for important perinatal and infant outcomes (1).
This systematic review of systematic reviews found 42 systematic reviews of 204 primary studies that evaluated either vitamin D supplementation in pregnant women and/or examined the association between serum vitamin D levels for at least one predefined perinatal outcome (1). The researchers evaluated the systematic reviews for research quality using the AMSTAR tool and only analyzed data from the 13 systematic reviews with high AMSTAR scores.
The systematic reviews of randomized controlled trials (RCTs) with the highest quality of evidence showed no benefits from vitamin D supplementation regarding preterm birth, preeclampsia, gestational diabetes, stillbirth, low birth weight or caesarean section (1). A significant difference was found for small-for-gestational age; however, this evidence was low quality for two reasons: 1) the high risks of bias in the included studies without an accompanying sensitivity analysis to examine the low risk of bias studies separately, and 2) imprecision due to the small numbers of small-for-gestational age births in the included studies. Systematic reviews of observational studies showed that women with low 25-hyroxy-vitamin D levels had higher rates of preterm birth, preeclampsia, gestational diabetes and small-for-gestational age.
The findings of this systematic review (1) reinforce the findings of a 2017 systematic review (2) that found that the superior health of people with higher vitamin D serum levels suggested by the frequent associations observed in observational studies are not seen in randomized trials of vitamin D supplementation. Additionally, there is increasing evidence that serum 25-hyroxy-vitamin D, the vitamin D status marker, is a negative acute phase reactant, which decreases in response to other variables (2-9). Specifically, researchers have observed that 25-hyroxy-vitamin D decreases in response to inflammation (3), acute illness (4), ill health (2), critical illness (5), surgery (6,7) and when C-reactive protein increases (3,7-9). If a marker changes in response to other variables, then it has limited use as a nutritional adequacy marker.
- Bialy L, Fenton T, Shulhan-Kilroy J, Johnson DW, McNeil DA, Hartling L. Vitamin D supplementation to improve pregnancy and perinatal outcomes: an overview of 42 systematic reviews. BMJ Open. 2020 Jan 20;10(1):e032626. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/31964667
- Autier P, Mullie P, Macacu A, Dragomir M, Boniol M, Coppens K, et al. Effect of vitamin D supplementation on non-skeletal disorders: a systematic review of meta-analyses and randomised trials. Lancet Diabetes Endocrinol. 2017 Dec;5(12):986-1004. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/29102433
- McMillan DC, Maguire D, Talwar D. Relationship between nutritional status and the systemic inflammatory response: micronutrients. Proc Nutr Soc. 2019 Feb;78(1):56-67. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/30220267
- Kostoglou-Athanassiou I, Pantazi E, Kontogiannis S, Kousouris D, Mavropoulos I, Athanassiou P. Vitamin D in acutely ill patients. J Int Med Res. 2018 Oct;46(10):4246-57. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/30157690
- Czarnik T, Czarnik A, Gawda R, Gawor M, Piwoda M, Marszalski M, et al. Vitamin D kinetics in the acute phase of critical illness: a prospective observational study. J Crit Care. 2018 Feb;43:294-9. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/28968524
- Binkley N, Coursin D, Krueger D, Iglar P, Heiner J, Illgen R, et al. Surgery alters parameters of vitamin D status and other laboratory results. Osteoporos Int. 2017 Mar;28(3):1013-20. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/27826645
- Waldron JL, Ashby HL, Cornes MP, Bechervaise J, Razavi C, Thomas OL, et al. Vitamin D: a negative acute phase reactant. J Clin Pathol. 2013 Jul;66(7):620-2. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/?term=23454726
- Kruit A, Zanen P. The association between vitamin D and C-reactive protein levels in patients with inflammatory and non-inflammatory diseases. Clin Biochem. 2016 May;49(7-8):534-7. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/?term=26778547
- Silva MC, Furlanetto TW. Does serum 25-hydroxyvitamin D decrease during acute-phase response? A systematic review. Nutr Res. 2015 Feb;35(2):91-6. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/?term=25631715
Can Selenium-rich Lentils Reduce Arsenic Toxicity in Chronically-Exposed Individuals?
New research examined the use of selenium-rich lentils as a method to reduce arsenic toxicity and arsenic levels in biological samples, and to improve health indicators in those with chronic exposure to arsenic from water and food.
A double-blind, cluster-randomized, placebo-controlled trial of 405 healthy Bangladesh people (14 to 75 years of age) with chronic exposure to arsenic was conducted (1). The intervention group (204 participants) was provided with 65 gm of selenium-rich lentils containing 55 μg selenium/day and the control group (201 participants) were provided with the same amount of lentils but of with low selenium levels (1.5 ug selenium/day). At baseline, three and six months, total arsenic levels were measured from urine, stool and blood samples and anthropometric measurements were taken. Hair samples were also taken at baseline and at six months follow up. Participants who consumed the selenium-rich lentils were found to be excreting more arsenic in their urine (measured as arsenic metabolite (dimethylasrsinic acid)) at six months compared to the control group (P=0.008). Some health indicators, including the incidence of allergy (P=0.02) and asthma (P=0.05), were lower in the intervention group compared to the control group, and body mass index was higher (P<0.01) (the participants’ average BMI was 22). The authors suggested that selenium-rich lentils can increase arsenic excretion and improve the health indicators among people with high arsenic exposure. They recommended longer term larger scale studies be conducted to verify these results and to examine if higher concentrations of selenium would provide additional health benefits.
For additional information on the potential health effects of consuming arsenic, see the following PEN Content:
Is the consumption of rice (white and brown) associated with increased arsenic-related health risks?
Food Safety - Arsenic in Rice Background
Trending Topic - Do New Parents or Parents-to-be Need to be Concerned with Dietary Arsenic Exposure?
- Smits JE, Krohn RM, Akhtar E, Hore SK, Yunus M, Vandenberg A, et al. Food as medicine: selenium enriched lentils offer relief against chronic arsenic poisoning in Bangladesh. Environ Res. 2019 Sept;176:108561. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/31299617
Food Trends in 2020
Registered dietitians, chefs and the food industry weigh in on expected food trends for the coming year. Common themes are an expected growth in the number of CBD-infused beverages and food products (particularly in Britain and Canada), more plant-based foods and alternative meat options, growing number of 'flexitarians' (those who follow a minimally plant-based diet) and considerations given to sustainable choices. Check out a few of our favourite predictions:
Happy New Year!
Coconut Oil Unveiled!
A recent Canadian Broadcasting Corporation’s Marketplace Program provided information about coconut oil’s saturated fat content as this fat has been widely promoted for health and weight loss (See Table 1 for an overview of the saturated, linoleic and linoleic acid fatty acid content of various oils). Marketplace interviewed Dr. St-Onge, the lead researcher for the 2003 randomized crossover study of 24 overweight men who, in random order, consumed prepared diets containing olive oil or medium chain triglyceride (MCT) oil for four weeks (1). Both of the diets had 40% of energy as fat, 15% as protein and 45% as carbohydrates and were identical except for the type of fats included. The MCT-containing diet used an oil for 75% of the dietary fat composed of: 65% MCT oil, 13% olive oil, 7% each of canola and flaxseed oil and 6% coconut oil. In the control diet, 75% of total fat was olive oil. The remainder of the fat came from other foods. Food energy was provided to maintain each individual’s weight. The results showed that energy expenditure was slightly but significantly greater in the MCT oil mixture by 0.04±0.02 kcal/min (P< 0.05) on day 2 but was not significantly different on day 28. There was no significant difference in the loss of whole-body subcutaneous adipose volume. Upper body adipose tissue decreased significantly with MCT oil compared to olive oil consumption (-0.67±0.26 kg and -0.02±0.19 kg, respectively (P<0.05)). Average fat oxidation was not significantly different on day 2 or day 28. The authors speculated that a “diet rich in MCTs results in greater loss of adipose tissue compared with LCTs, perhaps due to increased energy expenditure and fat oxidation observed with MCT intake. Thus, MCTs may be considered as agents that aid in the prevention of obesity or potentially stimulate weight loss ” (1).
St-Onge reported on the Marketplace Program that despite the fact that the study contained only minimal amounts of coconut oil (6% of fat in the MCT group) and coconut oil contains only 15% MCT (or less depending on how C12:0 lauric acid is classified (2)), this study is often used to promote the consumption of coconut oil. She described the situation as coconut oil being perceived as having a health halo and noted that she “would not consume [coconut oil] on a regular basis”.
Table 1. Saturated, Linoleic and Linoleic Acid Fatty Acid Contents of Commonly Consumed Oils (3)
Saturated % || Linoleic %
|| Linolenic % |
|| 87|| 1.8|| 0|
|| 51|| 2.7|| 0.3|
|| 40|| 10|| 1|
|| 18|| 42|| 0|
|| 17|| 32|| 0|
|| 16|| 51|| 6.8|
|| 14|| 41|| 0.3|
|| 14|| 10|| 0.8|
|| 13|| 54|| 1.2|
|| 12|| 13|| 1.0|
|| 9|| 29|| 0|
|| 7|| 19|| 9.1|
Dietary Reference Intakes
Fatty acids are essential nutrients with only small amounts required. Recommended Adequate Intakes for α-linolenic acid (omega-3) are 1.1 g/day adult females and 1.6 g/day adult males, aged 19-50 years. Recommended Adequate Intakes for linoleic acid (omega-6) are 12 g/day adult females and 17 g/day adult males, aged 19-50 years. Fats that have high proportions of saturated fats include coconut oil (87%) and butter (51%) (See Table 1).
While coconut oil is promoted for its ability to raise HDL, saturated fats raise both LDL and HDL. This effect is common among saturated fats and is not unique to coconut oil (5,6). Oils that contain PUFA lower LDL as well as slightly lower HDL (5). Oils containing both omega-3 and omega-6 fatty acids that are the most effective at lowering LDL cholesterol include canola, flax and soybean (5,6).
See Additional PEN Content:
Is a reduced saturated fat diet recommended for primary or secondary cardiovascular disease (CVD) prevention?
What effect do tropical oils (palm oil and coconut oil) have on blood lipids?
Currently, there is no need for substantial changes for people who consume saturated fats in amounts around 10% of energy (7) and who do not have elevated cardiovascular risk. Individuals with elevated cardiovascular risk should discuss their risk profile with a physician and a dietitian.
See Additional PEN Content:
Are there any health benefits in consuming coconut oil?
Should omega-3 fatty acids (fish or plant-based food or supplements) be recommended for the primary or secondary prevention of cardiovascular disease (CVD) in adults?
Article Analysis: Cardiovascular Effects of Exchanging Saturated Fat With an Oil High in Linoleic Acid - Not all Vegetable Oils are Created Equally
- St-Onge MP, Ross R, Parsons WD, Jones PJ. Medium-chain triglycerides increase energy expenditure and decrease adiposity in overweight men. Obes Res. 2003 Mar;11(3):395-402. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/12634436
- Dietitians of Canada. What effect do tropical oils (palm oil and coconut oil) have on blood lipids? In: Practice-based evidence in nutrition [PEN]. 2019 Jan 07 [cited 2019 Dec 19]. Available from: http://www.pennutrition.com. Access only by subscription.
- Health Canada. Canadian nutrient file. 2016. Available from: https://food-nutrition.canada.ca/cnf-fce/index-eng.jsp
- Institute of Medicine. Dietary reference intakes: the essential guide to nutrient requirements. The National Academies Press: Washington, DC; 2006. P 122. Available from: https://doi.org/10.17226/11537
- Schwingshackl L, Bogensberger B, Benčič A, Knüppel S, Boeing H, Hoffmann G. Effects of oils and solid fats on blood lipids: a systematic review and network meta-analysis. J Lipid Res. 2018 Sep;59(9):1771-82. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/30006369
- Dietitians of Canada. Is a reduced saturated fat diet recommended for primary or secondary cardiovascular disease (CVD) prevention? In: Practice-based evidence in nutrition [PEN]. 2019 Jan 07 [cited 2019 Dec 19]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2671&pqcatid=146&pqid=25600. Access only by subscription.
- U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015–2020 Dietary
guidelines for Americans. 8th Edition. December 2015. Available from: http://health.gov/dietaryguidelines/2015/guidelines/
Adult Obesity Management Practice Guidelines
With the recent posting of the Weight Stigma Background in the PEN database, a heads up that in early 2020 the Canadian Adult Clinical Practice Guidelines for Obesity Management are due to be released. Keep a watch for them on the Obesity Canada: Clinical Guidelines page.
For other related country guidelines refer to the International Weights/Obesity Guideline Collection (Children and Adults).
Plant-based Beverages Are Not a Good Alternative for Young Children
Plant-based beverages continue to grow in popularity. There is a misconception that these beverages are healthy and nutritionally equivalent to cow’s milk but this is not the case (1). A comparison of the nutritional value of plant-based beverages in Canada, was covered recently in a televised news segment on the CTV Network.
The nutrient composition of plant-based beverages can become a problem for young children. With the exception of fortified soy beverages, if plant-based beverages displace breastmilk, formula or cow’s milk, young children can be at the risk of malnutrition. Plant-based beverages, excluding soy (soy-fortified beverages have a similar nutrient profile to cow’s milk), are very low in protein, calories and fat (1,2). There are currently 21 reports and case series published in the literature of severe malnutrition and nutritional disease in children who consumed rice and nut beverages instead of breastmilk, formula or cow’s milk (3-23). This number is up from seven reports noted in 2016 (2). While many plant-based beverages are fortified with vitamins and minerals, the amounts vary widely, and it is not known if the bioavailability of the minerals and protein is the same as cow’s milk (1,3,24).
A recently released technical scientific report, from a panel of experts representing key national health and nutrition organizations in the U.S., recommended for young children that “Consumption of [plant milks] as a full replacement for dairy milk should be undertaken in consultation with a health care provider so that adequate intake of key nutrients commonly obtained from dairy milk can be considered in dietary planning” (1).
For country-specific (Australia, Canada, New Zealand, U.K.) recommendations for consuming plant-based beverages, see the PEN Practice Question: What are recommendations for the use of plant-based beverages (e.g. soy, rice, almond, coconut and oat milk/beverage) during the complementary feeding period in infants?
For more information on the potential health implications of plant-based beverages in young children, see the PEN Trending Topic: Plant-based Beverages – Are They Really Healthier for Young Children, and the Dietitians of Canada News Release: Dietitians, paediatricians advise parents to exercise caution with plant-based beverages.
For information and practical tips for providing children with healthy drinks see the website: https://healthydrinkshealthykids.org (Note: this is a U.S. website and recommendations are based on the technical scientific report noted above (1). These recommendations may be different from other country recommendations, particularly around juice consumption.
- Lott M, Callahan E, Welker Duffy E, Story M, Daniels S. Healthy beverage consumption in early childhood: recommendations from key national health and nutrition organizations. Technical Scientific Report. Durham, NC: Healthy Eating Research; 2019. Available from: http://healthyeatingresearch.org
- Dietitians of Canada. What are the recommendations for the use of plant-based beverages (e.g. soy, rice, almond, coconut and oat milk/beverage) during the complementary feeding period in infants? In: Practice-based Evidence in Nutrition [PEN]. 2016 Apr 14 [cited 2019 Oct 29]. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2503&pqcatid=146&pqid=19553&kppid=19554&book=Evidence&num=1#Evidence. Access by subscription only.
- Vitoria I. The nutritional limitations of plant-based beverages in infancy and childhood. Nutr Hosp. 2017;34(5):1205-214. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/29130721
- Ellis D, Lieb J. Hyperoxaluria and genitourinary disorders in children ingesting almond milk products. J Pediatr. 2015 Nov;167(5):1155-8. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/26382627
- Diamanti A, Pedicelli S, D'Argenio P, Panetta F, Alterio A, Torre G. Iatrogenic kwashiorkor in three infants on a diet of rice beverages. Pediatr Allergy Immunol. 2011. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/22122793
- Barreto-Chang OL, Barreto-Chang O, Pearson D, Shepard WE, Longhurst CA, Longhurst C, et al. Vitamin D -deficient rickets in a child with cow's milk allergy. Nutr Clin Pract. 2010 Aug;25(4):394-8. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/20702845
- Mesa Medina O, González JL, García Nieto V, Romero Ramírez S, Marrero Pérez C. Infant metabolic alkalosis of dietetic origin. An Pediatr (Barc). 2009 Apr;70(4):370-3. Spanish. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/19303829
- Kuhl J, Davis MD, Kalaaji AN, Kamath PS, Hand JL, Peine CJ. Skin signs as the presenting manifestation of severe nutritional deficiency: report of 2 cases. Arch Dermatol. 2004 May;140(5):521-4. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/15148094
- Novembre E, Leo G, Cianferoni A, Bernardini R, Pucci N, Vierucci A. Severe hypoproteinemia in infant with AD. Allergy. 2003 Jan;58(1):88-9. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/12580819
- Doron D, Hershkop K, Granot E. Nutritional deficits resulting from an almond-based infant diet. Clin Nutr. 2001 Jun;20(3):259-61. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/11407873
- Massa G, Vanoppen A, Gillis P, Aerssens P, Alliet P, Raes M. Protein malnutrition due to replacement of milk by rice drink. Eur J Pediatr. 2001 Jun;160(6):382-4. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/11421421
- Kanaka C, Schütz B, Zuppinger KA. Risks of alternative nutrition in infancy: a case report of severe iodine and carnitine deficiency. Eur J Pediatr. 1992 Oct;151(10):786-8. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/1425805
- Vitoria I, López B, Gómez J, Torres C, Guasp M, Calvo I, Dalmau J. Improper use of a plant-based vitamin C-deficient beverage causes scurvy in an infant. Pediatrics. 2016 Feb;137(2):e20152781. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/26783325
- Mori F, Serranti D, Barni S, Pucci N, Rossi ME, de Martino M, et al. A kwashiorkor case due to the use of an exclusive rice milk diet to treat atopic dermatitis. Nutr J. 2015 Aug 21;14:83. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/26293684
- Le Louer B, Lemale J, Garcette K, Orzechowski C, Chalvon A, Girardet JP, et al. Severe nutritional deficiencies in young infants with inappropriate plant milk consumption. Arch Pediatr. 2014 May;21(5):483-8. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/24726668
- Alvares M, Kao L, Mittal V, Wuu A, Clark A, Bird JA. Misdiagnosed food allergy resulting in severe malnutrition in an infant. Pediatrics. 2013 Jul;132(1):e229-32. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/23733797
- Katz KA, Mahlberg BA, Honig PJ, Yan AC. Rice nightmare: kwashiorkor in 2 Philadelphia-area infants fed Rice Dream beverage. J Am Acad Dermatol. 2005 May;52(5 Suppl 1):S69-72. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/15858513
- Carvalho NF, Kenney RD, Carrington PH, Hall DE. Severe nutritional deficiencies in toddlers resulting from health food milk alternatives. Pediatrics. 2001 Apr:107(4):e46. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/11335767
- Keller MD, Shuker M, Heimall J, Cianferoni A. Severe malnutrition resulting from use of rice milk in food elimination diets for atopic dermatitis. Isr Med Assoc J. 2012 Jan;14(1):40-2. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/22624441
- Fourreau D, Peretti N, Hengy B, Gillet Y, Courtil-Teyssedre S, Hess L, et al. [Pediatric nutrition: severe deficiency complications by using vegetable beverages, four cases report]. Presse Med. 2013 Feb;42(2):e37-43. [French]. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/23021957
- Tierney EP, Sage RJ, Shwayder T. Kwashiorkor from a severe dietary restriction in an 8-month infant in suburban Detroit, Michigan: case report and review of the literature. Int J Dermatol. 2010 May;49(5):500-6. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/20534082
- Liu T, Howard RM, Mancini AJ, Weston WL, Paller AS, Drolet BA, et al. Kwashiorkor in the United States: fad diets, perceived and true milk allergy, and nutritional ignorance. Arch Dermatol. 2001 May;137(5):630-6. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/11346341
- Imataka G, Mikami T, Yamanouchi H, Kano K, Eguchi M. Vitamin D deficiency rickets due to soybean milk. J Paediatr Child Health. 2004 Mar;40(3):154-5. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/15009584
- Singhal S, Baker RD, Baker SS. A comparison of the nutritional value of cow's milk and nondairy beverages. J Pediatr Gastroenterol Nutr. 2017 May;64(5):799-805. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/27540708
Red and Processed Meat – It’s All About Interpretation
The International Agency for Research on Cancer (IARC) reported in 2015 that high processed meat or red meat diets are associated with higher relative risks of cancer, with stronger negative evidence for processed meats than red meat (1).
Johnston et al recently published a series of five systematic reviews in Annals of Internal Medicine that recommended that adults continue to consume red meat and processed meat at current levels of intake (2). These researchers considered three servings per week as a realistic reduction in meat consumption. Using meta-analyses to summarize the findings, they interpreted the data in two ways: they quantified how many per 1000 people would likely benefit from reducing red and processed meat consumption and then used Grading of Recommendations Assessment, Development and Evaluation (GRADE) tools (3,4) to translate these findings into recommendations.
Both the IARC and Johnston et al recognized limitations of the strengths of the evidence about red and processed meats (1,2). It was when Johnston et al interpreted their findings and made their recommendations that they differed from IARC’s conclusions. Johnston et al (1) used GRADE tools (4) to translate the findings into absolute risk differences and then make recommendations. GRADE instructs researchers when making recommendations to transparently consider the evidence concerning effects on health, as well as to consider values and preferences, costs, acceptability and feasibility of a recommendation. The GRADE methods have been endorsed by over 100 organizations including the World Health Organization and the Cochrane Collaboration (5).
Both groups looked at the body of evidence, which is observational study data. Regarding cancer, the IARC reported relative risks and statistical significance.
“Positive associations of colorectal cancer with consumption of processed meat were reported in 12 of the 18 cohort studies that provided relevant data, including studies in Europe, Japan, and the USA. Supporting evidence came from six of nine informative case-control studies. A meta-analysis of colorectal cancer in ten cohort studies reported a statistically significant dose–response relationship, with a 17% increased risk (95% CI 1•05–1•31) per 100 g per day of red meat and an 18% increase (95% CI 1•10–1•28) per 50 g per day of processed meat” (1).
Johnston et al translated their summary of the evidence into absolute risks of having a cardiometabolic or cancer outcome event:
“Although statistically significant, low- to very low-certainty evidence indicates that adherence to dietary patterns lower in red or processed meat is associated with a very small absolute risk reduction in 9 major cardiometabolic and cancer outcomes (range, 1 fewer to 18 fewer events per 1000 persons), with no statistically significant differences for 21 additional outcomes observed” (2).
The Johnston et al (2) group were divided when they voted about their recommendations to “continue current levels of red meat and processed meat consumption” (11 voted for the recommendation, three voted against it). They considered the following data for their recommendation:
- the low to very low certainty of evidence for the potential adverse health outcomes
- the very small absolute risk reduction based on three fewer servings of red or processed meat per week
- the small risk reductions combined with “peoples' attachment to their meat-based diet”, “is not likely to provide sufficient motivation to reduce consumption of red meat or processed meat”
- the large variability in peoples' values and preferences related to meat, and
- the panel focused exclusively on health outcomes associated with meat and did not consider animal welfare and environmental issues.
There is strong criticism of Johnson et al's paper. As an example, a press release from the Harvard T.H. Chan School of Public Health described the Johnston et al publication as “irresponsible and unethical to issue dietary guidelines that are tantamount to promoting meat consumption” (6).
Interpreting the Evidence
GRADE recommends looking beyond statistical significance to examine several quality of research indicators and the actual numerical strength of the effects. (See PEN®
eNews article - Why Using GRADE (to grade the evidence in PEN®) is Important to Practicing Dietitians
). The GRADE tools are intended to be used to evaluate the body of evidence about any health interventions for its strength, consistency, directness and precision for improving health and the individual studies for the risks of bias. (Refer to PEN®
eNews article, How PEN is ‘GRADE’ing the Evidence for You
for reasons why PEN is using GRADE methods). Essentially, both those who recommend continued meat consumption (2) and those who recommend decreased meat consumption (1,5) have made subjective assessments to judge the evidence and make their recommendations. Being transparent based on the GRADE methods, the new analysis (2) may be more substantiated, but as before, the evidence is not strong and decisions about eating or not eating meat comes down to individual preferences.
Many nutrition science recommendations are based on observational studies of what people eat and their subsequent health outcomes. A weakness of this approach is that people who eat healthy diets usually have higher incomes, do not smoke and practice other healthy lifestyles including more physical activity and a moderate alcohol intake. It is challenging, if not impossible, to disentangle these effects to be able to say that a healthy diet is the reason for better health outcomes.
There is no strong evidence to definitively support either the recommendations for continued red and processed meat consumption (2) or decreased meat consumption (1). The new analysis by Johnston et al (2) is based on the latest and endorsed methods (5) to summarize essentially the same evidence and to make recommendations. By using recommended methods, the new report (2) may be more substantiated. However, individual preferences and choices about eating meat are key to how we as dietitians work with clients.
The weaker the evidence, the more dietitians’ knowledge and professional training matter to interpret and to provide nutrition guidance. We need to continue to respect people’s values and preferences as well as to encourage a variety of foods in moderation and to make wise and informed choices to meet nutrition needs. Those who avoid or decrease their meat consumption for health, environmental and/or animal welfare reasons may need assistance obtaining sufficient protein, iron, zinc and vitamin B12. Those who avoid dairy products, may need assistance obtaining sufficient protein and calcium, especially children (7). People who eat generous quantities of meat may need assistance to ensure their diet contains sufficient vegetables, fruit, calcium and fibre.
Most diets would likely be improved with the inclusion of some plant-based proteins including some beans, lentils and nuts for their fibre, low glycemic index and nutrient contributions. Recommended nutrient intakes for protein (8) and current country dietary guidelines should continue to be followed. See Additional Content: International Healthy Eating Guideline Collection.
- Bouvard V, Loomis D, Guyton KZ, Grosse Y, Chissassi FE, Benbrahim-Tallaa L, et al. Carcinogenicity of consumption of red and processed meat. Lancet Oncol. 2015 Dec;16(16):1599-600. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/26514947
- Johnston BC, Zeraatkar D, Han MA, Vernooij RWN, Dib EL, Marshall C, et al. Unprocessed red meat and processed meat consumption: dietary guideline recommendations (NutriRECS) Consortium. Ann Intern Med. 2019 Oct. doi:10 .7326/M19-1621. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/31569235
- Guyatt GH, Oxman AD, Akl EA, Kunz R, Vist G, Brozek J, et al. GRADE guideline: 1. Introduction – GRADE evidence profiles and summary of findings tables. J Clin Epidemiol. 2011 Apr;64(4):383-94. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/21195583
- Schünemann H, Brożek J, Guyatt G and Andrew Oxman A, Eds. Handbook for grading the quality of evidence and the strength of recommendations using the GRADE approach. 2013. Available from: https://gdt.gradepro.org/app/handbook/handbook.html
- GRADE. GRADE working group. [cited 2019 Oct 2]. Available from: http://www.gradeworkinggroup.org/
- Harvard T.H. Chan School of Public Health. New “guidelines” say continue red meat consumption habits, but recommendations contradict evidence. The Nutrition Source. 2019 Sep 30. Available from: https://www.hsph.harvard.edu/nutritionsource/2019/09/30/flawed-guidelines-red-processed-meat/
- The National Academies Press. Dietary Reference Intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. 2005. Available from: https://www.nap.edu/read/10490/chapter/12
Twelve Country Comparison of Packaged Food and Beverages Using Health Star Rating System
The Health Star Rating (HSR) system was used to compare 394,815 packaged foods and beverages available in 12 countries (1). This study identified encouraging and concerning results. Encouraging for residents of Britain, Australia, Canada and the U.S is that these countries' packaged foods ranked the highest for their overall nutrient profiles, while the foods in India, Hong Kong, China and Chile ranked the lowest. The authors suggested that the differences between high and low-middle income countries may be due to the lack of food labelling in low-middle income countries or an inability to implement and enforce healthy food policies. As well, there could be a demand by consumers in high income countries for healthier foods and more actions from the food industry to produce healthier products. However, not all of the high ranking countries had consistent ratings across all nutrients. Perhaps the most concerning for Canadians was that packaged foods in the “US and Canada had the highest mean sodium content of all 12 countries examined”.
There are limits to nutrient profiling systems that should be kept in mind. No food rating system is perfect. The HSR is based on nutrients in the foods per 100 g or 100 mL, an evaluation method that rates some foods more or less favourably than systems that evaluate foods per 100 kilocalories or in usual serving sizes (2,3). In studies, nutrient profiling systems based on 100 kcal and serving sizes perform better than those based on 100 g, such as the HSR (4). For example, foods that are consumed in low quantities, such as cheese, are rated poorly by the HSR system for the saturated fat and sodium contents when assessed per 100 grams, while cheese is likely seldom consumed in 50-100 g servings (2,5). In contrast, foods that are consumed in large quantities, such as soup and juices, have their sodium and sugars contents assessed in unrealistically low serving sizes of 100 mL. The same problem happens with the desirable nutrients when assessed per 100 g, but in the opposite direction. Almonds are sometimes quoted as a source of calcium, as they have 247 mg/100 g (6). However, at 587 kcal/100 g, almonds may not be a very good source of calcium/day for many people. In comparison 1 and 2% milk and calcium-fortified soy beverages have 34 to 52 kcal/100 g and supply 234 to 374 mg of calcium per 100 kcal.
Another observation of the HSR is that it considers total sugars and does not discriminate between innate sugars versus added sugars, which lowers the ratings of some foods such as unsweetened fruit (7). Other factors that the HSR system does not consider are foods’ affordability (8), and the amount of processing the food has undergone (4).
While classifying foods by their nutrients does not address all aspects of a healthy diet, when used along with other interventions, nutrient profiling systems may help to improve the dietary intake of consumers (9). The authors of this study concluded that nutrient profiling systems are important for the development and monitoring of healthy food policies and products (1).
For information on the effects of food labelling systems, nutrition panels and menus on consumer behaviour see the PEN Food and Nutrition Labelling Knowledge Pathway.
- Dunford EK, Ni Mhurchu C, Huang L, Vandevijvere S, Swinburn B, Pravst I, et al. A comparison of the healthiness of packaged foods and beverages from 12 countries using the Health Star Rating nutrient profiling system, 2013-2018. Obes. Rev. 2019 Jul 22. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/31328385
- Dickie S, Woods JL, Lawrence M. Analysing the use of the Australian Health Star Rating system by level of food processing. Int J Behav Nutr Phys Act. 2018 Dec 13;15(1):128 Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/30545373
- Drewnowski A. Nutrient density: addressing the challenge of obesity. Br J Nutr. 2018 Aug;120(s1):S8-14. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/29081311
- Drewnowski A, Fulgoni VL 3rd. Nutrient density: principles and evaluation tools. Am J Clin Nutr. 2014 May;99(5 Suppl):1223S-8S. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/24646818
- Mhurchu CN, Eyles H, Choi YH. Effects of a voluntary front-of-pack nutrition labelling system on packaged food reformulation: the Health Star Rating System in New Zealand. Nutrient. 2017 Aug 22;9(8). Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/28829380
- Government of Canada. Canadian Nutrient File (CNF) – Search by Food. 2018 Feb 6. Available from: https://food-nutrition.canada.ca/cnf-fce/index-eng.jsp
- Menday H, Neal B, Wu JHY, Crino M, Baines S, Petersen KS. Use of added sugars instead of total sugars may improve the capacity of the Health Star Rating System to discriminate between core and discretionary foods. J Acad Nutr Diet. 2017 Dec;117(12):1921-30.e.11. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/29173348
- Cooper SL, Pelly FE, Lowe JB. Assessment of the construct validity of the Australian Health Star Rating: a nutrient profiling diagnostic accuracy study. Eur J Clin Nutr. 2017 Nov;71(11):1353-9. Abstract available from: https://www.ncbi.nlm.gov/pubmed/28294168
- World Health Organization. Nutrient Profiling. [cited 2019 Sep 3]. Available from: https://www.who.int/nutrition/topics/profiling/en/
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