1) Jackson, S. L., King, S. M. C., Park, S., Fang, J., Odom, E. C., & Cogswell, M. E. (2015). Health professional advice and adult action to reduce sodium intake. American Journal of Preventive Medicine.

A study published in the American Journal of Preventive Medicine found that more than half of U.S. adults surveyed are trying to reduce their sodium intake, and that advice from a medical professional is strongly associated with reducing sodium intake.

• The researchers analyzed data from the optional sodium module on the 2013 Behavioral Risk Factor Surveillance System, a nationwide state-based telephone survey. The data used in this study was gathered from 173,778 (non-institutionalized) respondents from 26 states, the District of Columbia, and Puerto Rico.

• 53% of adults overall reported taking action to reduce their sodium intake. This percentage was higher among blacks (68%) and Hispanics (63%). The prevalence of taking action was highest among those who received medical advice (83%), followed by adults taking antihypertensive medications (75%), adults with a history of cardiovascular disease (75%), adults with diabetes (74%), and adults with kidney disease (73%). The prevalence was lowest among 18 to 24 year-olds (29%).

• 23% of adults reported receiving medical advice to reduce their sodium intake, and receiving this advice was associated with taking action (prevalence ratio=1.59; 95% CI=1.56, 1.61), independent of sociodemographic and health characteristics.

2) Anderson, C. A., Cobb, L. K., Miller, E. R., Woodward, M., Hottenstein, A., Chang, A. R., … & Appel, L. J. (2015). Effects of a behavioral intervention that emphasizes spices and herbs on adherence to recommended sodium intake: Results of the SPICE randomized clinical trial. The American Journal of Clinical Nutrition, 102(3), 671-679.

The results of a behavioral intervention published in The American Journal of Clinical Nutrition showed that study participants who used more spices and herbs when cooking consumed less salt, suggesting counseling sessions which show participants how to make food taste good without relying too much on salt can be beneficial for health and well-being.

• The study included adults 18 years and older. The Dietary Guidelines for Americans recommends 1500 mg of sodium per day for this demographic. The mean age was 61 years old, and the mean BMI was 30. Of the study population, 88% were African American, and 63% had high blood pressure.
• In the first phase of the study, 55 individuals were given a low-sodium diet for four weeks to get them used to eating less salt. Participants were provided all food, snacks, and beverages.
• In the second phase, 40 participants from phase 1 were randomly assigned to either a behavioral intervention to reduce sodium intake or a self-directed control group for 20 weeks. The behavioral intervention included individual and group counseling sessions emphasizing the use of spices to replace salt, as well as keeping track of how much sodium they were consuming.
• At the end of phase 2, the mean 24-hour sodium excretion was 956.8 mg/day lower in the behavioral intervention group than in the control group. These findings suggest that counseling which emphasizes the use of spices and herbs in cooking, along with guided sodium reduction, can help people reduce their sodium intake.

3) Wielgosz, A., Robinson, C., Mao, Y., Jiang, Y., Campbell, N. R., Muthuri, S., & Morrison, H. (2015). The Impact of Using Different Methods to Assess Completeness of 24‐Hour Urine Collection on Estimating Dietary Sodium. The Journal of Clinical Hypertension.

The standard method of determining sodium intake is the 24-hour urine test, in which all urine over a 24-hour period is collected in one or more containers and then sent to a lab for analysis. However, this has the potential for human error. A study published in The Journal of Clinical Hypertension found that depending on the method used for assessing complete urine collection, the estimate of mean sodium intake varied by almost 3600 mg per 24-hour period – a substantial difference.

• In 2009, 507 volunteers were recruited from the Champlain Community Heart Healthy Study in Eastern Ontario to conduct a 24-hour urine survey for dietary sodium.

• The “gold standard” for ensuring the accuracy of 24-hour sodium collection involves administering para-aminobenzoic acid (PABA) three times during the urine collection, as this chemical is almost completely excreted in the urine during the 24-hour collection period. However, this is rather complex for participants and can be costly, so other indirect methods for assessing urine collection are more commonly used. In this study, the investigators focused on creatinine excretion rate to determine the accuracy of urine collection. Men typically excrete 15-25 mg/kg every 24 hours, while women excrete 10-24 mg/kg every 24 hours. However, creatinine excretion rates are affected by many factors, including diet, muscle mass, kidney function, substances competing with creatinine for renal transporters, ethnicity, and age.

• Four creatinine-based urine inclusion/exclusion criteria were applied to analyses, and the results were then compared. One analysis excluded samples for which the measured creatinine excretion rate was biologically implausible. The second only included those individuals whose creatinine levels fell within the standard creatinine excretion rates. The third method excluded only those with low values of measured creatinine excretion rates. The fourth used a linear regression model to estimate the expected creatinine excretion rate from a regression equation, built on records with standard creatinine rates; samples were then excluded if the 24-hour creatinine excretion was less than 15% or greater than 50% of their predicted expected rate.

• Depending on the method used for assessing complete urine collection, mean sodium intake varied between 3648 mg/24 hours and 7210 mg/24 hours.

• The large degree of variation indicates a strong need to establish more pragmatic yet cost-effective methods to accurately measure sodium intake from 24-hour urine tests.

This month’s Research Roundup was compiled by Aviva Musicus, a first-year doctoral student whose research includes food marketing, labeling, and the effectiveness of sugar-sweetened beverage regulation. She previously worked at the Center for Science in the Public Interest, where she conducted research and lobbied for added sugar and sodium reduction, the elimination of trans fats from the food supply, and improved agricultural biotechnology regulations.

1) Cardel M, Lema DJ, Jackson KH, et al. (2015) Higher intake of PUFAs is associated with lower total and visceral adiposity and higher lean mass in a racially diverse sample of children. Journal of Nutrition 145(9): 2146-52.

We know that eating a diet with adequate intake of  polyunsaturated fats is important, but new finding suggest this may have important benefits for children.

• In recent cross-sectional study of 311 US children between the ages of 7 and 12, children who ate the highest amount of polyunsaturated fats (both omega-3 and omega-6) had more lean body mass, a lower percentage of body fat, and less intra-abdominal fat.
• Children also had a significantly lower body fat percentage and less intra-abdominal fat if they consumed more polyunsaturated fat than saturated fat. For this reason, keeping in mind sources of both of these types of dietary fat while preparing meals is key.
• Cooking with olive oil, soybean oil, and other liquid vegetable oils, and providing your children with snacks like walnuts, peanut butter, or avocados may help a child minimize body fat and maximize lean muscle.

2) Fung TT, Pan A, Hou T, et al. (2015) Long-term change in diet quality is associated with body weight change in men and women. Journal of Nutrition 145(8): 1850-6.

We all know the importance of a healthy diet, but a recent study that included men and women from three different cohorts – the Nurses’ Health Studies I and II, and the Health Professionals Follow-Up Study – provided further support for that point when they investigated the effect of following one of three different healthy dietary patterns on weight change over time.

• The investigators examined changes in adherence to three dietary patterns: a Mediterranean-type diet, a diet following the Healthy Eating Pyramid (Alternate Healthy Eating Index-2010), or the Dietary Approaches to Stop Hypertension (DASH) diet. All of these diets emphasize a high intake of fruits and vegetables, whole grains, and nuts.
• Improvements in diet quality were associated with less weight gain over time among both men and women.
• The benefits of improving diet quality were more profound among those who were overweight and obese compared to those who were of normal weight, and among women less than 55 years of age.
• The importance of increasing physical activity along with diet quality was also examined, and those who had the highest amounts of physical activity along with an improved diet experienced the least amount of weight gain over time.
• The findings of this study add further evidence that increasing intake of fruits, vegetables, whole grains, and nuts and lowering intake of refined grains, sweets, and red and processed meats will help keep weight in control.

3) Chew EY, Clemons RE, Agron E, et al. (2015) Effect of omega-3 fatty acids, lutein/zeaxanthin, or other nutrient supplementation on cognitive function: The AREDS2 randomized clinical trial. JAMA 314(8): 791-801.

Evidence from observational studies has suggested that omega-3 long-chain polyunsaturated fatty acids such a DHA and EPA may reduce cognitive decline, and that antioxidants such as lutein and zeaxanthin may have similar benefits.

• However, the AREDS2 (Age-Related Eye Disease Study 2) study, a double-blind randomized clinical trial, found no significant differences in cognitive function over the course of the study between those who received supplementation – of omega 3s, lutein and zeaxanthin, or a combination of both – when compared to those who received no supplementation.
• This may be because the study participants were, on average, already 72.7 years old, and the supplementation may have been initiated too late in the aging process or because the duration of the study – 5 years – may not have been long enough to see a significant effect from supplementation.

This month’s Research Roundup was compiled by Nathalie Marchand, a third year doctoral student who has been researching the many effects of diet on diseases of aging, such as osteoarthritis and dementia.

1) Guyton KZ, Loomis D, Grosse Y, et al. (2015) Carcinogenicity of tetrachlorvinphos, parathion, malathion, diazinon, and glyphosate. The Lancet Oncology 16(5): 490-1.

In March, 2015, 17 experts from 11 countries assessed the carcinogenicity of five pesticides including glyphosate at the International Agency for Research on Cancer. A summary of the final evaluations was published in The Lancet Oncology.

• In this report, glyphosate was classified as “probably carcinogenic to humans” (Group 2A) for non-Hodgkin lymphoma, indicating there was limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in animals. Specifically, increased risk of non-Hodgkin lymphoma was consistent across case-control studies of occupational exposure in the USA, Canada, and Sweden. However, no evidence of increased risk of non-Hodgkin lymphoma was observed in the large Agricultural Health Study cohort (AHS).
• The evidence of other cancer sites (skin tumors, renal tubule carcinoma, haemangiosarcoma, and pancreatic islet-cell adenoma) was limited to animal studies.
• Evidence suggested the potential mechanisms for cancer were primarily through two pathways: First, the chemicals damaged DNA, which caused mutations or alterations in their gene codes. Second, glyphosate could induce oxidative stress. Oxidative stress happens when highly reactive chemicals overwhelm the capacity of cells to deactivate them. Often, free radicals will be produced during this process, and they can interact with molecules in the body and damage various cell components. If the cells cannot effectively counteract this production, cells can become necrotic and die.

2) Mesnage R, Arno M, Costanzo M, et al. (2015) Transcriptome profile analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure. Environmental Health 14(1): 70.

An experimental study published in Environmental Health showed that chronic exposure to an ultra-low dose of glyphosate resulted in liver and kidney damage in rats.

• In this study, researchers administered 2-year minute doses (0.1ppb) of Roundup via drinking water, which was representative of what could be found in contaminated tap water.
• First, the authors observed the signs of pathological and biochemical changes in the liver and kidneys of the exposed rats.
• Then, they analyzed the changes in gene expression of these organs. Compared to the control group, more than 4000 gene transcript clusters in the liver and kidneys showed alterations in the exposed rats.
• The findings demonstrated that chronic exposure to glyphosate at an environmental level resulted in liver and kidney damage in an animal toxicity model, which may potentially have health implications for both animal and human populations.

3) Balbuena MS, Tison L, Hahn ML, et al. (2015) Effects of sublethal doses of glyphosate on honeybee navigation. The Journal of Experimental Biology 218(Pt 17): 2799-805.

An experimental study published in The Journal of Experimental Biology showed that exposure to sublethal doses of glyphosate affect the homeward flight path of honeybees in an open field.

• The authors performed an experiment in which forager honeybees were fed with a sugar solution containing traces of glyphosate in three sublethal concentrations (2.5, 5, and 10 mg/l) and released from a new site.
• The honeybees treated with a higher glyphosate concentration (10mg/l) spent more time performing homeward flights than control bees or bees treated with lower concentrations.
• The results suggest that exposure to glyphosate in a level commonly found in agricultural settings impaired the honeybees’ navigation, with potential long-term negative consequences for the foraging success of honeybees.

Due to widespread use of glyphosate, the residues are found in American’s urine, breast milk, and drinking water. The IARC has concluded that glyphosate is probably carcinogenic for non-Hodgkin lymphoma, and the risk of other cancer sites is inconclusive. In addition to health concerns, weed resistance to glyphosate has been increasing, which will adversely affect farm production. Due to the developing weed resistance, the Environmental Protection Agency is planning to place new restrictions on glyphosate. However, the details of the regulations have not yet been released at this time.

This month’s Research Roundup was compiled by Yu-Han Chiu, a third year doctoral student who has been researching dietary factors in relation to semen quality and other reproductive outcomes. Dr. Chiu has been working with her advisor Dr. Jorge Chavarro and her colleagues on developing a dietary pesticide burden score to estimate an individual’s pesticide exposure from food intake. Using this method, they recently presented important new data on pesticide exposure via fruit and vegetable intake in relation to semen quality in the journal Human Reproduction.