Accurate Measurements Suggest High Salt Intake Leads To Higher Death Rate

MedicalResearch.com Interview with:
Salt-Sodium
Dr. Feng J He PhD
Wolfson Institute of Preventive Medicine,
Barts and The London School of Medicine & Dentistry,
Queen Mary University of London,
London

MedicalResearch.com: What is the background for this study?

Response: Studies have shown that there is a strong linear relationship between sodium intake and blood pressure and raised blood pressure is a leading cause of death and disability worldwide.

The current mean population sodium intake among adults in most countries is approximately 4,000 mg/d (10 g/d salt). The World Health Organisation (WHO) has recommended a 30% reduction in sodium intake by 2025 with an eventual target of less than 2,000 mg/d (5 g/d salt) for all countries. Several recent cohort studies have challenged the WHO’s recommendations, as these studies suggested that there was a J or U-shaped relationship between sodium and risk, i.e. lower and higher sodium intake both were associated with an increased risk of cardiovascular events and deaths.

However, these studies have several severe methodological problems, one of which is the use of a biased or unreliable estimate of individual’s usual sodium intake, e.g. a single spot urine with the Kawasaki formula.

Our study, for the first time, has compared the relationship of sodium intake and mortality, based on various methods to assess usual sodium intake, including estimates based on the Kawasaki formula (single and average of multiple days) and a single measured 24-hour urine, with the gold standard method, i.e. the average of multiple non-consecutive measured 24-h urines.

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Low Sodium Levels Linked To Cognitive Impairment in Older Adults

MedicalResearch.com Interview with:

Dr. Kristen L. Nowak PhD Division of Renal Diseases and Hypertension University of Colorado Anschutz Medical Campus Aurora, CO 80045

Dr. Nowak

Dr. Kristen L. Nowak PhD
Division of Renal Diseases and Hypertension
University of Colorado Anschutz Medical Campus
Aurora, CO 80045

MedicalResearch.com: What is the background for this study?  

Response: Subtle impairments in cognition are common with aging, even in the absence of clinically apparent dementia. Mild hyponatremia is a common finding in older adults; however, the association of lower serum sodium with cognition in older adults is currently uncertain.

We hypothesized that lower normal serum sodium would be associated with prevalent cognitive impairment and the risk of cognitive decline over time in asymptomatic, community-dwelling older men.

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DASH Diet and Sodium Reduction Can Have Big Impact in Improving Blood Pressure

MedicalResearch.com Interview with:

Stephen P. Juraschek, MD, PhD Instructor of Medicine Beth Israel Deaconess Medical Center/Harvard Medical School

Dr. Juraschek

Stephen P. Juraschek, MD, PhD
Instructor of Medicine
Beth Israel Deaconess Medical Center/Harvard Medical School 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: The DASH-Sodium trial demonstrated that both the DASH diet and sodium restriction, individually and combined, lowered blood pressure in adults with pre-hypertension or stage 1 hypertension. Whether these effects varied by level of blood pressure prior to starting these interventions was unknown. In a secondary analysis of the original DASH diet it had been observed that the effects from DASH were greater among adults with higher blood pressure (systolic greater than or equal to 140 mm Hg) at baseline with the appearance of even greater effects among people with baseline systolic blood pressures above 150 mm Hg. However, this has never been shown. Furthermore, it was unknown whether sodium reduction followed a similar linear trend of greater effects among adults with more severely uncontrolled systolic blood pressure.

In our study, we found that effects were indeed greater in adults with a baseline systolic blood pressure of 150 mm Hg or greater. Furthermore, the combined systolic blood pressure-lowering effect from both interventions was as high was 20 mm Hg. This is a magnitude comparable if not greater than medications for lowering blood pressure.

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Salt Content in Restaurant Food Remains High

MedicalResearch.com Interview with:

Julia Wolfson, PhD MPP Assistant Professor Department of Health Management and Policy Department of Nutritional Sciences University of Michigan School of Public Health Ann Arbor, MI 48109

Dr. Wolfson

Julia Wolfson, PhD MPP
Assistant Professor
Department of Health Management and Policy
Department of Nutritional Sciences
University of Michigan School of Public Health
Ann Arbor, MI 48109

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Over the past several years, Large chain restaurants in the United States have made some progress in introducing new lower calorie items on their menus. Since 2012, calories of items consistently on restaurant menus in all years have not significantly change. In this study, we examined the sodium content of restaurant menu items among 66 of the 100 largest restaurants in the US. We examined sodium content among items on the menu in all years (2012-2016) and among newly introduced items in 2013, 2014, 2015 and 2016 compared to items on the menu in 2012 only.

We found that sodium content of menu items on the menu in all years did not change, but that restaurants were introducing new, lower sodium menu items. However, sodium content of restaurant menu items remains high. This is important because diets high in sodium are associated with serious adverse health outcomes including hypertension, stroke and cardiovascular disease.

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Salt Intake From Packaged Foods Decreasing But Still Too High

MedicalResearch.com Interview with:

Jennifer Poti, PhD Research Assistant Professor Nutritional Epidemiology Gillings School of Global Public Health University of North Carolina at Chapel Hill

Dr. Poti

Jennifer Poti, PhD
Research Assistant Professor
Nutritional Epidemiology
Gillings School of Global Public Health
University of North Carolina at Chapel Hill

MedicalResearch.com: What is the background for this study?

Response: Although strong evidence links excessive sodium intake to hypertension, a leading risk factor for cardiovascular disease, the majority of American children and adults have sodium intake that exceeds the recommended upper limit for daily sodium intake.

To lower sodium intake at the population-level, the Institute of Medicine has recommended that reducing sodium in packaged foods will be essential and has emphasized the need to monitor sodium in the US food supply. However, little is known about whether sodium in packaged foods has changed during the past 15 years.

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Children Eating Too Much Salt At Every Meal

MedicalResearch.com Interview with:

Zerleen S. Quader, MPH CDC

Zerleen S. Quader

Zerleen S. Quader, MPH
CDC

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Sodium reduction is considered a key public health strategy to reduce cardiovascular disease nationwide, and this study is the latest in ongoing CDC efforts to monitor U.S. sodium intake.

Eating habits and taste for salt are established early in life by what children eat. Eating too much sodium can set them up for high blood pressure now and health problems later. Previous evidence suggests that one in nine children already has blood pressure above the normal range, and strong evidence has shown that reducing sodium intake reduces blood pressure – and lowering blood pressure lowers the risk of cardiovascular disease among adults. With voluntary efforts already underway by some manufacturers to lower the sodium and added sugar content in some of their products, these findings help provide a baseline to monitor changes in the food industry, as well as sodium intake among U.S. youth.

We examined data from the 2011-2012 National Health and Nutrition Examination Survey (NHANES) to determine sodium intake by major food category, place and eating occasion. We found that average sodium intake among participants was 3,256 mg, and that doesn’t include salt added at the table. On the day of assessment, nearly 90 percent exceeded the upper level of sodium recommended for a healthy diet.

• There were some variations based on age and gender. For example:
o Average intake was highest among high school-aged children
o Girls had significantly lower daily intake than boys (for example, 2,919 mg versus 3,584 mg)
• In addition, we found that ten types of food make up nearly half of youth sodium intake nationwide, including pizza, bread, lunch meats and snack foods.

We also analyzed where the foods were obtained and found that approximately 58 percent of sodium comes from store foods, 16 percent from fast food and pizza restaurants and 10 percent from school cafeteria foods. And when we looked at occasion, we discovered that 39 percent of sodium intake was consumed at dinner, 31 percent at lunch, 16 percent from snacks and 14 percent from breakfast.
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Lower Salt Intake Linked To Decreased Blood Pressure, Heart Disease and Mortality

MedicalResearch.com Interview with:

Nancy Cook ScD Professor of Medicine, Harvard Medical School Professor in the Department of Epidemiology Harvard T.H. Chan School Public Health Brigham & Women’s Hospital Division of Preventive Medicine Boston, MA 0221

Dr. Nancy Cook

Nancy Cook ScD
Professor of Medicine, Harvard Medical School
Professor in the Department of Epidemiology
Harvard T.H. Chan School Public Health
Brigham & Women’s Hospital Division of Preventive Medicine
Boston, MA 02215

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: The association of sodium intake with later mortality has been controversial. While there is a well-accepted effect on blood pressure, the effects of sodium on later cardiovascular disease, and particularly mortality, have been subject to dispute. While the adverse effects of high sodium are now widely accepted, effects at lower levels of sodium intake are less clear. Some recent studies have found a J-shaped relationship, with increased disease rates among those consuming lower levels of sodium, contrary to the effects on blood pressure.

In contrast, we found a direct linear relationship of usual intake of sodium with later mortality over 20 years of follow-up. Those with the lowest sodium intake experienced the lowest mortality. Our measure of intake was based on the average over 1-3 years of several measures of 24hr urine sodium excretion, the gold standard of sodium measurement. This is much more precise than measurements based on a single 24hr sodium excretion or especially on a spot urine sample, which is used in many publications that found the J-shaped curve. Our data were assessed in a healthy cohort of men and women without hypertension or cardiovascular disease, so had less potential bias due to these factors. We thus believe that our results showing the lowest mortality among those consuming the lowest levels of sodium are more accurate.

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High Salt Intake Linked to Increased Cardiovascular Disease in CKD Patients

MedicalResearch.com Interview with:

Jiang He, M.D., Ph.D. Joseph S. Copes Chair and Professor Department of Epidemiology School of Public Health and Tropical Medicine Tulane University, New Orleans

Dr. Jiang He

Jiang He, M.D., Ph.D.
Joseph S. Copes Chair and Professor
Department of Epidemiology
School of Public Health and Tropical Medicine
Tulane University, New Orleans

MedicalResearch: What is the background for this study?

Dr. Jiang He: Chronic kidney disease is associated with increased risk of end-stage renal disease, cardiovascular disease, and all-cause mortality. A positive association between sodium intake and blood pressure is well established in observational studies and clinical trials. However, the association between sodium intake and clinical cardiovascular disease remains less clear. Positive monotonic, J-shaped, and U-shaped associations have been reported. Methodologic limitations, including inconsistencies in dietary sodium measurement methods, could be contributing to these conflicting findings. Furthermore, no previous studies have examined the association between sodium intake and incident cardiovascular disease among patients with chronic kidney disease.

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Controversy Over Salt Content Continues

Salt-SodiumMedicalResearch.com Interview with:
Prof Andrew Mente PhD
Clinical Epidemiology and Biostatistics, McMaster University
Hamilton, Canada

MedicalResearch.com Editor’s Note:  Dr. Mente discusses his Lancet publication regarding salt intake below.  Dr. Mente’s findings are disputed by the American Heart Association (AHA).  A statement from the AHA follows Dr. Mente’s comments.

MedicalResearch.com: What is the background for this study? What are the main findings?

Prof. Mente: Several prospective cohort studies have recently reported that both too little and too much sodium intake is associated with cardiovascular disease or mortality. Whether these associations vary between those individuals with and without high blood pressure (hypertension) is unknown.

We found that low sodium intake (below 3 g/day), compared to average intake (3 to 6 g/day), is associated with more cardiovascular events and mortality, both in those with high blood pressure and in those without high blood pressure. So following the guidelines would put you at increased risk, compared to consuming an sodium at the population average level, regardless of whether you have high blood pressure or normal blood pressure.

High sodium intake (above 6 g/day) compared to average intake, was associated with harm, but only in people with high blood pressure (no association in people without high blood pressure).

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Only a Few Neurons in Brain Responsible For Salt Hunger

MedicalResearch.com Interview with:

Matthew Bailey PhD Faculty Principal Investigator British Heart Foundation Centre for Cardiovascular Science The University of Edinburgh, Edinburgh, United Kingdom.

Dr. Mathew Bailey

Matthew Bailey PhD
Faculty Principal Investigator
British Heart Foundation Centre for Cardiovascular Science
The University of Edinburgh, Edinburgh, United Kingdom.

MedicalResearch.com: What is the background for this study?

Dr. Bailey: This study started with our interest in salt homeostasis and long term blood pressure, so it’s firmly rooted in the cardiovascular/renal disease risk factor arena. We were interested in salt-sensitivity- why does blood pressure go up in some people when they eat salt but not in others. I’m a renal physiologist, so we had a number of papers looking at renal salt excretion and blood pressure. We initially used a gene targeting approach to remove a gene (Hsd11b2) which acts as a suppressor of the mineralocorticoid pathway. It’s mainly expressed in the kidney and when we deleted the gene  throughout the body we saw a number of renal abnormalities all associated with high mineralocorticoid activity. This was consistent with the “hypertension follows the kidney” theory of blood pressure control. There is a human disease called “Apparent Mineralocorticoid Excess”- there are people do not have the gene and are thought to have renal hypertension. Our study threw up some anomalies which we couldn’t easily interpret but suggested that the brain was involved. We moved to a more refined technology that allowed us to knockout a gene in one organ system but not another. We knew the gene was in the brain and localized to a very restricted subset of neurons linked to salt-appetite and blood pressure control. Previous studies had shown that these neurons were activated in salt-depleted rats (ie rats that needed to eat salt). We started there but didn’t anticipate that the effect on salt hunger and on blood pressure would be so large because renal function is -as far as we can tell- normal.

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Nearly All Americans Consume More Salt Than Recommended

Click Here for More on Salt/Sodium on MedicalResearch.com

Sandra L Jackson PhD Epidemic Intelligence Service, CDC Division for Heart Disease and Stroke Prevention National Center for Chronic Disease Prevention and Health Promotion Atlanta, Georgi

Dr. Sandra Jackson

MedicalResearch.com Interview with:
Sandra L Jackson PhD
Epidemic Intelligence Service, CDC
Division for Heart Disease and Stroke Prevention
National Center for Chronic Disease Prevention and Health Promotion
Atlanta, Georgia

Medical Research: What is the background for this study? What are the main findings?

Dr. Jackson: Sodium reduction is an important public health strategy to reduce cardiovascular disease, and this study was the latest in CDC’s ongoing effort to monitor U.S. sodium intake. These findings reveal that nearly all Americans – regardless of age, race and gender – consume more sodium than is recommended for a healthy diet.

Specifically, over 90 percent of children (2 to 18) and 89 percent of adults (19 and up) eat more than the recommended limits in the 2015-2020 Dietary Guidelines for Americans, and that doesn’t even include salt added at the table. The newly released guidelines recommend limiting sodium to less than 2,300 mg per day for people over the age of 14, and less for those younger.

The analysis also examined specific populations. Among adults, a larger proportion of men (98 percent) than women (80 percent) consume too much sodium. Among people at greater risk of developing heart disease or stroke – such as people age 51 and older, African Americans and individuals with high blood pressure or pre-hypertension (blood pressure higher than normal but not in the “high” range) – more than three out of four exceed 2,300 mg per day. Adults with hypertension consume slightly less sodium than other adults, and may be trying to follow physician’s advice to reduce sodium. However, 86 percent of adults with hypertension still consume too much.

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Could Increased Salt In Processed Food Contribute To Rise in MS Cases?

Dimitry N. Krementsov PhD Research Associate University of Vermont Burlington, VT 05405MedicalResearch.com Interview with:
Dimitry N. Krementsov PhD
Research Associate
University of Vermont
Burlington, VT 05405

Medical Research: What is the background for this study? What are the main findings?

Dr. Krementsov:  Multiple sclerosis (MS) is the most common disabling neurologic disorder affecting young adults. The disease is initiated by the individual’s own immune system attacking the central nervous system (brain and spinal cord).Multiple sclerosis is complex and is controlled by the interplay between sex/gender, genetics, and environmental factors. How this happens is not well understood, but an intriguing clue is that MS incidence over the last 50-100 years has been increasing in women and not men, suggesting that a recent environmental change is affecting MS preferentially in females.

There are several well-documented risk factors for Multiple Scleroisis, including Epstein-Barr virus infection, low sunlight exposure, low vitamin D, and smoking. Recent studies have suggested the existence of a new risk factor – high intake of dietary salt. In our study, we sought to understand how this environmental factor may interact with genetics and sex.

We used an animal model of MS, called experimental autoimmune encephalomyelitis (EAE), in laboratory mice. The advantage of this approach is the ability to precisely control both the genetics and the environment, something that cannot be done in epidemiological studies in humans. Just as in previous studies, we found that when mice were fed a high salt diet, their MS-like disease got worse.

Importantly, we found that this was dependent on genetics and sex; when we varied the genetic background of the mice, we saw three different outcomes:
1) an effect of salt in both males and females,
2) an effect only in females, and
3) no effect in either sex.

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Mild Increase in Daily Sodium Increases Risk of Hypertension

Salt-SodiumMedicalResearch.com Interview with:
Tomonori Sugiura, MD, PhD
Department of Cardio‐Renal Medicine and Hypertension
Nagoya City University Graduate School of Medical Sciences
Nagoya  Japan

Medical Research: What is the background for this study? What are the main findings?

Dr. Sugiura: Although there is a close relationship between dietary sodium and hypertension, the concept that individuals with relatively high dietary sodium are at increased risk of developing hypertension compared to those with relatively low dietary sodium, has not been intensively studied in a cohort. Therefore, the present observational study was designed to investigate whether individual levels of dietary sodium critically affect future increases in blood pressure in the general population.

The main findings of this study were that a relatively high level of dietary sodium intake and also a gradual increase in dietary sodium, estimated by urinary sodium excretion, are associated with a future increase in blood pressure and the incidence of hypertension in the general population.

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Potassium May Play Larger Role Than Sodium in Adolescent Blood Pressure

Lynn L. Moore, DSc, MPH Department of Medicine Boston University School of Medicine Boston, Massachusetts MedicalResearch.com Interview with:
Lynn L. Moore, DSc, MPH

Department of Medicine
Boston University School of Medicine
Boston, Massachusetts

Medical Research: What is the background for this study?

Dr. Moore: The USDA’s current Dietary Guidelines for sodium intake have become increasingly controversial. Current recommendations include restricting sodium intake after the age of 2 years to no more than 2300 mg per day. For African-American adults and children, intakes should be restricted to no more than 1500 mg per day. Actual intake levels are much higher, with most Americans consuming about 3500 mg per day. Our goal was to estimate the effects of dietary sodium and potassium intakes on the change in blood pressure throughout adolescence.

We used data from the National Growth and Health Study, a prospective study of more than 2000 girls who were 9-10 years of age at the time of enrollment. Lifestyle factors were assessed repeatedly throughout the study, and blood pressure was measured annually. Dietary sodium and potassium were assessed using multiple sets of three-day diet records. We used longitudinal modeling to estimate the effects of dietary sodium and potassium on blood pressure change over 10 years.

Medical Research: What are the main findings?

Dr. Moore: In this study, there was no evidence for a beneficial effect of reduced sodium intake on blood pressure change during adolescence. By 19-20 years of age, girls who consumed more than 4000 mg of sodium per day had systolic and diastolic blood pressure levels that were similar to those seen among girls with lower levels of sodium intake. Specifically, there was no beneficial effect on blood pressure associated with sodium intakes of less than 2500 mg per day. These results were similar for blacks and whites. In contrast, the repeated measures analyses showed that girls who consumed more than 2400 mg of potassium per day had lower blood pressures throughout adolescence compared with girls consuming less than 1800 mg per day of potassium.

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Salt Capsules May Not Improve Exercise Performance For Endurance Athletes

Edward "Ted" Weiss, Ph.D. Associate Professor Department of Nutrition and Dietetics Saint Louis University Saint Louis MO 63104MedicalResearch.com Interview with:
Edward “Ted” Weiss, Ph.D
.
Associate Professor
Department of Nutrition and Dietetics
Saint Louis University
Saint Louis MO 63104

Medical Research: What is the background for this study? What are the main findings?

Dr. Weiss: Public health recommendations are to keep sodium consumption below 2300 mg/day to avoid adverse health effects. However, most people in the US consume over 4000 mg/day. Furthermore, endurance athletes are often advised to add sodium to their diets to replace the sodium that is lost in sweat and are often lead to believe that the additional sodium is important for exercise performance. Clearly these recommendations are at odds with each other.

In a double-blind placebo-controlled trial, we evaluated the effect of salt capsule consumption (containing a 1800 mg sodium) on exercise performance and on thermoregulation during 2 – 2.5 hours of running or cycling. Exercise performance was not different between the salt and placebo conditions (i.e. it didn’t provide benefit or harm for performance) nor did any of the markers of thermoregulation differ, suggesting that the salt didn’t help (or hurt) the body’s ability to cool itself.

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Young Children May Acquire A Taste For Salt From Common Foods In Infancy

Joyce Maalouf MS MPH Nutrition Epidemiologist CDC, AtlantaMedicalResearch.com Interview with:
Joyce Maalouf MS MPH
Nutrition Epidemiologist
CDC, Atlanta

Medical Research: What is the background for this study? What are the main findings?

Response: Although significant research shows U.S. children are eating too much sodium, data on the top dietary sources contributing to that intake is limited – particularly among babies and toddlers. This study identifies the primary sources of dietary sodium consumed by children from birth to 24-months-old, as well as differences in intake and food source broken down by demographic characteristics including age, gender and race/ethnicity.

Overall, our research revealed that after the age of six months, more than 70 percent of sodium intake comes from foods other than breast milk and infant formula. Commercial baby foods, soups and pasta mixed dishes are top sodium contributors for U.S. infants 6 to 11.9 months, while soups, cheese, pasta mixed dishes and frankfurters and sausages are key contributors among toddlers aged 12 up to 24 months. Top sodium sources varied by race/ethnicity within age groups, suggesting that for sodium reduction to be effective, it needs to occur across a wide variety of foods.

In addition, we found that non-Hispanic black toddlers ate more sodium than non-Hispanic white and Mexican-American children. Average sodium intake increased almost 9-fold from children under six months to those between one and two-years-old, while average energy intake only doubled. This suggests that, during the first two years of life, U.S. children increasingly consume sodium-rich foods.

To determine these findings, we examined eight years of data encompassing more than 2,900 participants between birth and two-years-old. The information was pulled from the nationwide NHANES What We Eat in America survey between 2003 and 2010.

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Sodium Content In Commercial Foods Remains High and Variable

Jaspreet Ahuja, Nutritionist USDA, Agricultural Research Service Nutrient Data Laboratory Beltsville, MD 20705MedicalResearch.com Interview with: Jaspreet Ahuja, Nutritionist
USDA, Agricultural Research Service
Nutrient Data Laboratory
Beltsville, MD 20705

MedicalResearch: What is the background for this study? What are the main findings?

Response: Most sodium in the U.S. diet comes from commercially processed and restaurant foods. Sodium reduction in these foods is key to several recent public health efforts. In this paper, we provide an overview of a program led by Nutrient Data Laboratory, USDA, in partnership with CDC and FDA to monitor sodium contents in commercially processed and restaurant foods in United States.

We track about 125 highly consumed, sodium-contributing foods, termed “Sentinel Foods” annually using information from food manufacturers and periodically by nationwide sampling and laboratory analyses. In addition, we monitor over 1,100 other commercially processed and restaurant food items, termed “Priority-2 Foods,” biennially using information from food manufacturers. These foods serve as indicators for assessing changes in the sodium content of commercially processed and restaurant foods in the U.S. In addition to sodium, we are monitoring related nutrients (potassium, total dietary fiber, total and saturated fat, total sugar) because their levels may change when manufacturers and restaurants reformulate their products to reduce their sodium content.

We sampled all Sentinel Foods nationwide and reviewed all Priority-2 Foods in 2010–2013 to determine baseline sodium concentrations. The results of sodium reduction efforts, based on re-sampling of the Sentinel Foods or re-review of P2Fs, will become available in 2015 on our website. The updated data are also released in USDA food composition databases, National Nutrient Database for Standard Reference and Food and Nutrient Database for Dietary Studies.

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Some Athletes May Need Salt Supplementation During Endurance Events

MedicalResearch.com Interview with:
Juan Del Coso Garrigós
Profesor CC. de la Act. Física y del Deporte
Responsable del Laboratorio de Fisiología del Ejercicio
UNIVERSIDAD CAMILO JOSÉ CELA

MedicalResearch: What is the background for this study? What are the main findings?

Response: From a scientific point of view, it is well known that salt (either in capsules or included in a drink) can improve physical performance and several other physiological factors such as plasma volume maintenance, thermoregulation, etc in endurance activities.  These effects are more evident when the amount of salt ingested during exercise matches the amount of salt lost by sweating.  By using only sports drinks, it is impossible to replace all the salt lost by sweating because they only contain a relatively small amount of salt in their compositions (between ½ and 1/3 of the amount of salt lost by sweating).

In fact, some of the investigations that determined the effectiveness of ingesting salt in sports have been financed by most popular sport drinks trademarks.  However, sports drink companies only include a part of the salt lost by sweating because for them, taste is elemental for their markets!  I suppose that, if they include more salt in their commercially available drinks, they would be more effective to prevent dehydration and performance decline, but at the same time, the taste of the drink would diminish the amount of beverage ingested worldwide.

In this case, in the sport drinks market there is a well- established balance between taste and physiological effectiveness.

As an example, most “salted” sport drinks contain 20-25 mM of sodium while it is well known that sweat sodium concentration ranges from 20 to 60 mM (salty sweater can reach 100 mM!!).  This is not a regulatory limitation, because UE considers sports drinks to carbohydrate-electrolyte solutions that contain sodium between 20 and 50 mM.

Our main finding is: To ingest salt capsules, in addition to the habitual rehydration routines with sports drinks, improves performance in a triathlon.  This ergogenic effect was mediated by better maintenance of body water and electrolytes balances.

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More Medical Advice May Help Patients Reduce Salt Intake

Dr. Sandra L. Jackson, Ph.D., M.P.H Epidemic intelligence service fellow Centers for Disease Control and Prevention, Chamblee, GAMedicalResearch.com Interview with:
Dr. Sandra L. Jackson, Ph.D., M.P.H
Epidemic intelligence service fellow
Centers for Disease Control and Prevention, Chamblee, GA

Medical Research: What is the background for this study? What are the main findings?

Dr. Jackson: With more than 90 percent of U.S. adults exceeding recommended sodium intake levels, healthcare providers can play a key role in counseling patients on the importance of limiting salt in the diet.

To assess the impact of medical advice on an individual’s efforts to reduce sodium intake, CDC researchers examined self-reported telephone survey information from nearly 174,000 U.S. adults. Overall, more than half of the respondents reported watching or reducing their sodium intake in 2013 – but less than one quarter (23 percent) said they received advice from a doctor or healthcare professional about sodium reduction. Of those that received the medical advice, 82 percent reported taking action to limit their sodium intake. In comparison, only 44 percent of respondents who reported not receiving medical advice said they took steps to reduce sodium.

The substantial proportion of patients who are not receiving medical advice (77%), according to these findings, reveals a missed opportunity to reduce sodium intake, particularly among groups that have a higher risk of developing cardiovascular disease. This includes African Americans, and those with high blood pressure, diabetes or chronic kidney disease.

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Sodium Reduction Not Linked To Higher Fasting Glucose Concentrations

Sheena M. Patel, MPH, ORISE, Fellow Division for Heart Disease and Stroke Prevention CDCMedicalResearch.com Interview with:
Sheena M. Patel, MPH, ORISE, Fellow
Division for Heart Disease and Stroke Prevention
CDC

MedicalResearch: What is the background for this study? What are the main findings?

Dr. Patel: Although significant evidence reveals reduced sodium intake lowers blood pressure, some studies report that sodium reduction could have a negative impact on insulin resistance and glucose tolerance. As a result, we conducted a comprehensive meta-analysis of intervention studies to examine the effect of sodium reduction on glucose tolerance and provide direction for future research.

Overall, our research found sodium reduction did not lead to higher average fasting glucose concentrations, a measure of insulin resistance. This suggests that the current recommendations to reduce sodium intake are unlikely to cause harm related to hyperglycemia or insulin resistance. It’s important to note that, in some cases, sodium reduction was associated with higher average insulin concentrations. However, this finding varied significantly across studies, suggesting caution in interpreting this result.

To determine these findings, we reviewed previously published randomized and non-randomized prospective intervention trials. In randomized trials, people have an equal chance of being in each group examined. The data was pulled from five databases with research spanning from January 1950 to August 2014 and included 38 trials.

MedicalResearch: What should clinicians and patients take away from your report?

Dr. Patel: This study is meaningful because it suggests short-term large reductions in sodium intake might not affect fasting glucose concentrations, a measure of insulin resistance.  These findings can help clinicians, patients and public health representatives focus efforts as needed.

Due to the overwhelming evidence in favor of reducing sodium intake, CDC continues to support sodium reduction as an achievable and effective public health strategy to lower blood pressure and improve heart health nationwide.

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Patel: This meta-analysis revealed no evidence that, in trials with a short intervention and large reductions in sodium, circulating glucose concentrations differed between groups. Further research could more rigorously examine the impact of sodium reduction on glucose tolerance, including ensuring that participants are randomly assigned to interventions, test longer intervention durations, incorporate sodium intake levels relevant to population reduction initiatives, and examine the longer-term measures of glucose tolerance, e.g., glycated hemoglobin.

Citation:

Dietary Sodium Reduction Does Not Affect Circulating Glucose Concentrations in Fasting Children or Adults: Findings from a Systematic Review and Meta-Analysis

Sheena M Patel, Paul Cobb, Sharon Saydah, Xuanping Zhang, Janet M de Jesus, and Mary E Cogswell

Nutr. 2015 jn.114.195982; first published online January 21, 2015. doi:10.3945/jn.114.195982

MedicalResearch.com Interview with:, & Sheena M. Patel, MPH, ORISE, Fellow (2015). Sodium Reduction Not Linked To Higher Fasting Glucose Concentrations MedicalResearch.com

Brain Functions May Be Affected By Chronic High Salt Intake

Charles Bourque PhD James McGill Professor Centre for Research in Neuroscience Montreal General Hospital Montreal QC, CanadaMedicalResearch.com Interview with:
Charles Bourque PhD
James McGill Professor
Centre for Research in Neuroscience
Montreal General Hospital Montreal QC, Canada

Medical Research: What is the background for this study? What are the main findings?

Dr. Bourque: Previous work has established that there is a link between a high level of dietary salt intake and the development of hypertension. In particular, so-called “salt-sensitive” individuals display increases in blood pressure that correlate with significantly increased levels of serum sodium concentration. Increased sodium levels are known to cause an excitation of vasopressin (VP)-releasing neurons of the hypothalamus. We therefore tested the hypothesis that this increase can contribute to the increase in blood pressure associated with high sodium intake in rats.

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Is Strict Salt Limit Necessary For Older Adults?

Andreas Kalogeropoulos, MD MPH PhD Assistant Professor of Medicine (Cardiology) Emory University School of Medicine Emory Clinical Cardiovascular Research Institute Atlanta GA 30322MedicalResearch.com Interview with:
Andreas Kalogeropoulos, MD MPH PhD

Assistant Professor of Medicine (Cardiology)
Emory University School of Medicine Emory Clinical Cardiovascular Research Institute
Atlanta GA 30322

Medical Research: What is the background for this study? What are the main findings?

Dr. Kalogeropoulos: There is ongoing debate on how low should we go when it comes to dietary sodium (salt) restriction recommendations. In this study, we examined the association between self-reported dietary sodium intake and 10-year risk for death, cardiovascular disease, and heart failure in approximately 2,600 adults 71-80 years old. The subjects (women: 51.2%; white: 61.7%; black: 38.3%) were participants of the community-based Health, Aging, and Body Composition Study, which is sponsored by NIH and focuses on aging processes, i.e. was not specifically designed to address the issue of dietary salt intake. Also, it is important to note that salt intake was self-reported (not objectively measured) using a food frequency questionnaire, which underestimates salt intake. Keeping these limitations in mind, we did not observe a significant association between self-reported sodium intake and 10-year mortality, cardiovascular disease, and heart failure. Ten-year mortality was lower in the group reporting 1500–2300 mg daily sodium intake (30.7%) compared to those reporting daily intake less than 1500 mg (33.8%) or over 2300 mg (35.2%); however, this difference was not statistically significant. The 10-year event rates for cardiovascular disease (28.5%, 28.2%, and 29.7%) and heart failure (15.7%, 14.3%, and 15.5%) were also comparable across the <1500-mg, 1500-2300-mg, and >2300-mg dietary sodium intake groups.

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Salt Intake Reduced By Warnings on Salt Containers

MedicalResearch.com Interview with: Zvonko Rumboldt, MD, PhD Professor emeritus Split University School of Medicine; Split, CroatiaMedicalResearch.com Interview with:
Zvonko Rumboldt, MD, PhD Professor emeritus
Split University School of Medicine;
Split, Croatia

Medical Research: What is the background for this study? What are the main findings?

Dr. Rumboldt: Arterial hypertension is the major common denominator of a number of cardiovascular diseases and untoward outcomes including stroke, myocardial infarction, terminal renal insufficiency, heart failure and death. Excessive salt intake is the leading causative factor of blood pressure elevation across the world. It has been shown beyond any reasonable doubt that reduction in salt consumption decreases the prevalence of arterial hypertension and eases its management. Therefore many endeavors and campaigns aimed at moderation in salt ingestion have been launched with fair but less than expected results. The main source of ingested salt in developed countries is processed food, while in transitional and developing countries it is addition during food preparation (cooking), serving and salting at the table.

This study, executed in Mostar, Bosnia and Herzegovina, and Split, Croatia, was designed to evaluate the effects of emphasized warning, consisting in self-adhesive stickers with clear, short message, put on household salt containers. Analyzed were 150 treated hypertensives, randomized in two groups, both receiving oral information and written leaflet concerning salt-hypertension relationship; the intervention group received in addition warning labels to be put on salt containers. In both groups measured were 24-hour urinary sodium excretion (natriuria), blood pressure, and several other parameters at inception of the trial, and one and two months later. In the intervention group observed was a marked decrease in sodium excretion (e.g. from 211 mmol/l at the beginning to 176 mmol/l at two months), much less (from some 207 to 200 mmol/l) in the control group. At the same time, the  mean blood pressure (already fairly well controlled) was reduced by additional 4 mm Hg in the intervention group (from 104 to 100 mm Hg), which was not the case in the control group (from 104 to 103 mm Hg).

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How Much Salt Intake Is Recommended For Patients With Heart Disease?

Jordi Salas-Salvadó Professor of Nutrition Human Nutrition Unit Department of Biochemistry & Biotechnology IISPV School of Medicine. Rovira i Virgili University CIBERobn, Instituto Carlos IIIMedicalResearch.com Interview with:
Jordi Salas-Salvadó Professor of Nutrition
Human Nutrition Unit Department of Biochemistry & Biotechnology
IISPV School of Medicine.
Rovira i Virgili University CIBERobn, Instituto Carlos III

Medical Research: What is the background for this study? What are the main findings?

Response: Excess sodium intake is associated with high blood pressure, a major risk factor for cardiovascular disease (CVD). The 2010 Dietary Guidelines for Americans recommended a sodium intake below 2300 mg per day (equivalent to less than 1 teaspoon of salt per day) in the general population. However it is unknown whether decreasing sodium intake below 2300 mg/d has an effect on CVD or all-cause mortality. The recent Institute of Medicine (IOM) explicitly concluded that studies on health outcomes are inconsistent in quality and insufficient in quantity to determine that sodium intake below 2300 mg/d may increase or decrease the risk of heart disease, stroke or all cause of mortality.

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Multiple Sclerosis: High Salt Intake Linked to More Relapses

MedicalResearch.com Interview with:
Dr. Mauricio Farez
Department of Neurology, Raúl Carrea Institute for Neurological Research
Buenos Aires, Argentina

Medical Research: What are the main findings of the study?

Dr. Farez: Our study shows that patients with Multiple Sclerosis (MS) with moderate to high sodium (salt) intake have also increased disease activity (more clinical relapses and more lesions on MRIs).

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