Too Many Sugary Sodas Might Harm Your Kidneys

Drinking lots of sweetened soda may increase the risk of developing chronic kidney disease, two new studies find.

“Consumption of 500 milliliters [16.9 fluid ounces] of a commercially available soft drink sweetened with high-fructose corn syrup increased vascular resistance in the kidneys within 30 minutes,” the researchers found.

In a second study, the investigators found changes in blood flow in the kidneys was caused by the corn syrup, not the caffeine, in the soda.

The two studies included a total of 25 healthy men and women, with an average age of 22 to 24.

Christopher Chapman, of the University at Buffalo in New York, and colleagues explained that vascular resistance occurs when blood vessels constrict, reducing blood flow in the kidneys and increasing blood pressure and impairing kidney function.

“Collectively, our findings indicate that [high-fructose corn syrup]-sweetened soft drink consumption increased renal vasoconstrictor tone at rest and during sympathetic activation,” the study authors said in a news release from the American Physiological Society.

The report was published online recently in the American Journal of Physiology–Renal Physiology.

Nearly 37 million Americans suffer from chronic kidney disease, according to the National Kidney Foundation. The foundation estimates kidney disease kills more people than breast cancer or prostate cancer.

Source: HealthDay


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Sugary Drinks Negatively Impact these Two Risk Factors for Heart Disease

There’s no sugarcoating it: Having too many sweet drinks may be linked to increased risk of cardiovascular disease in middle-aged and older adults, according to new research.

Drinking 12 ounces of sugary beverages more than once a day may lower “good” cholesterol and increase triglycerides, fat in the blood that can lead to heart disease.

“Reducing the number of or eliminating sugary drink consumption may be one strategy that could help people keep their triglyceride and good cholesterol at healthier levels,” lead study author Nicola McKeown said in a news release. McKeown is a nutrition epidemiologist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston.

Previous studies have shown added sugars increase heart disease risk. Beverages such as sodas, sports drinks and fruit-flavored drinks are the largest source of added sugar for Americans.

Researchers aimed to find out why and how these added sugars lead to heart disease. They hypothesized it could be a result of an unhealthy imbalance of cholesterol and triglyceride levels, a condition known as dyslipidemia that affects an estimated 40% to 50% of U.S. adults.

The observational study – published Wednesday in the Journal of the American Heart Association – examined medical data of nearly 6,000 people who were followed for an average of 12.5 years. Participants were classified into five groups according to how often they drank the different beverages, ranging from less than one serving per month to more than one serving per day.

The beverages were defined as: 12 ounces of sugary drinks, such as sodas, fruit-flavored drinks, sports drinks, and presweetened coffees and teas; 12 ounces of low-calorie sweetened beverages, including naturally and artificially sweetened “diet” sodas or other flavored drinks; or 8 ounces of 100% fruit juices, including orange, apple, grapefruit and other juices derived from whole fruits, with no added sugars.

Researchers found drinking more than 12 ounces per day of sugary beverages was associated with a 53% higher incidence of high triglycerides and a 98% higher incidence of low “good” cholesterol compared to those who drank less than 12 ounces per month.

Regularly drinking low-calorie sweetened beverages was not associated with increased dyslipidemia risk, nor was 100% fruit juice. However, researchers said more study is needed to back this finding.

“While our study didn’t find negative consequences on blood lipids from drinking low-calorie sweetened drinks, there may be health consequences of consuming these beverages on other risk factors,” McKeown said. “Water remains the preferred and healthiest beverage.”

Source: American Heart Association

Western Diet Rich in Fat and Sugar Linked to Skin Inflammation

A Western diet rich in fat and sugar may lead to inflammatory skin diseases such as psoriasis, a study by UC Davis Health researchers has found.

The study, published today in Journal of Investigative Dermatology, suggests that dietary components, rather than obesity itself, may lead to skin inflammation and the development of psoriasis. A common and chronic skin disease, psoriasis causes skin cells to form scales and red patches that are itchy and sometimes painful.

Diet and Skin Inflammation

Previous studies have shown that obesity is a risk factor for the development or worsening of psoriasis. The Western diet, characterized by a high dietary intake of saturated fats and sucrose and low intake of fiber, has been linked to the increased prevalence of obesity in the world.

“In our study, we found that short-term exposure to Western diet is able to induce psoriasis before significant body weight gain,” said Sam T. Hwang, professor and chair of dermatology at UC Davis and senior author on the study.

For the UC Davis Health study, which used a mouse model, Hwang and his colleagues found that a diet containing both high fat and high sugar (mimicking the Western diet in humans) was required to induce observable skin inflammation. In four weeks only, mice on Western diet had significantly increased ear swelling and visible dermatitis compared to mice fed a controlled diet and those on high fat diet alone.

“Eating an unhealthy diet does not affect your waistline alone, but your skin immunity too,” said Zhenrui Shi, visiting assistant researcher in UC Davis Department of Dermatology and lead author on the study.

Bile Acids and Skin Inflammation

The study detailed the mechanisms by which inflammation happens following a Western diet. It identified bile acids as key signaling molecules in the regulation of skin immunity. Bile acids are produced in the liver from cholesterol and metabolized in the intestine by the gut microbiota. They play an important role in dietary lipid absorption and cholesterol balance in the blood.

The study found that cholestyramine, a drug used to lower cholesterol levels by binding to bile acids in the intestine, helped reduce the risk of skin inflammation. The finding suggests that bile acids mediate the development of psoriasis. The binding of cholestyramine to bile acids in the gut and its subsequent release through the stool allows for lowering of skin inflammation.

Further studies are needed to understand the mechanism behind diet-induced skin inflammation and the interaction between metabolism, microbes and immunity.

Source: UC Davis

Study Examines the Relationship between Sugars and Heart Health

The impact of sugars on heart health depends on the dose and type of sugar consumed, suggests a new study led by researchers at St. Michael’s Hospital.

The team, led by Dr. John Sievenpiper, a staff physician in the Division of Endocrinology and Metabolism and a scientist at the Li Ka Shing Knowledge Institute, examined the relationship between total and added sugars that contain fructose on cardiovascular disease incidence and mortality.

Fructose is a naturally occurring sugar in many fruits and vegetables and makes up about half of the sugars in added sucrose and high-fructose corn syrup.

“We tend to think that sugars irrespective of the source are all bad, but this isn’t always the case,” said Dr. Sievenpiper. “Sugars behave differently depending on the type, dose and food source. Different sugars in varying amounts from different sources can have different effects on our health.”

Dr. Sievenpiper and his team wanted to find out whether there were harmful associations of fructose-containing sugars with heart health.

To do this, the team conducted a review of previous studies investigating the association between reported intakes of fructose-containing sugars derived from all reported sources and heart disease incidence and mortality.

The team found that different types of sugars showed different associations with cardiovascular disease. Higher intake of total sugars, fructose or added sugars was associated with increased death from cardiovascular disease, whereas higher intake of sucrose was associated with decreased death from cardiovascular disease.

The sugars that were associated with harm also showed thresholds for harm below which increased death from cardiovascular disease was not observed, ranging from 58 grams for fructose to 133 grams for total sugars.

Given the limitation that their data is largely observational in nature, Dr. Sievenpiper stressed that the certainty of their evidence is generally low and there is still a long way to go before fully understanding the relationship between sugars and heart health.

Next, the team plans to look at whether the differences seen by the type and dose of sugars can be explained by their food sources.

“We know that there are healthy and less healthy sources of sugar out there, but we want to know if these differences in sugars are driving the differences we’re seeing in the association with cardiovascular disease,” said Dr. Sievenpiper. “In other words, does it matter whether sugar comes from a healthier source such as fruit, yogurt, or a high-fibre, whole grain cereal versus a sugar-sweetened beverage.”

Source: EurekAlert!


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Drinking More Sugary Beverages of Any Type May Increase Type 2 Diabetes Risk

People who increase their consumption of sugary beverages—whether they contain added or naturally occurring sugar—may face moderately higher risk of type 2 diabetes, according to a new study from Harvard T.H. Chan School of Public Health. Drinking more sugar-sweetened beverages (SSBs), like soft drinks, as well as 100% fruit juices, was associated with higher type 2 diabetes risk.

The study also found that drinking more artificially sweetened beverages (ASBs) in place of sugary beverages did not appear to lessen diabetes risk. However, diabetes risk decreased when one daily serving of any type of sugary beverage was replaced with water, coffee, or tea. It is the first study to look at whether long-term changes in SSB and ASB consumption are linked with type 2 diabetes risk.

The study was published online October 3, 2019 in the journal Diabetes Care.

“The study provides further evidence demonstrating the health benefits associated with decreasing sugary beverage consumption and replacing these drinks with healthier alternatives like water, coffee, or tea,” said lead author Jean-Philippe Drouin-Chartier, postdoctoral fellow in the Department of Nutrition.

The study looked at 22–26 years’ worth of data from more than 192,000 men and women participating in three long-term studies—the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals’ Follow-up Study. Researchers calculated changes in participants’ sugary beverage consumption over time from their responses to food frequency questionnaires administered every four years.

After adjusting for variables such as body mass index, other dietary changes, and lifestyle habits, the researchers found that increasing total sugary beverage intake—including both SSBs and 100% fruit juice—by more than 4 ounces per day over a four-year period was associated with 16% higher diabetes risk in the following four years. Increasing consumption of ASBs by more than 4 ounces per day over four years was linked with 18% higher diabetes risk, but the authors said the findings regarding ASBs should be interpreted with caution due to the possibility of reverse causation (individuals already at high risk for diabetes may switch from sugary beverages to diet drinks) and surveillance bias (high-risk individuals are more likely to be screened for diabetes and thus diagnosed more rapidly).

The study also found that replacing one daily serving of a sugary beverage with water, coffee, or tea—but not with an ASB—was linked with a 2–10% lower risk of diabetes.

“The study results are in line with current recommendations to replace sugary beverages with noncaloric beverages free of artificial sweeteners. Although fruit juices contain some nutrients, their consumption should be moderated,” said Frank Hu, Fredrick J. Stare professor of nutrition and epidemiology and senior author of the study.

Source: Harvard T.H. Chan School of Public Health


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