Past Week in Nutrition Science (March 18th – 25th)

This is an overview of interesting nutrition research published from Friday, March 18th, to Friday, March 25th, 2016.

Woman With Fruit Background

Research Reviews

This week, we reviewed two articles: one from the International Journal of Obesityand the other from the Nutrition Journal.

Review: Gluten Increased Weight Gain in Mice.

Article: Wheat gluten intake increases weight gain and adiposity associated with reduced thermogenesis and energy expenditure in an animal model of obesity.

Summary: This was a controlled experiment examining the effects of a gluten-rich diet on weight gain in mice.

The study showed that feeding the mice with high amounts of gluten caused them to gain more weight, compared to a gluten-free diet. Whether gluten has similar effects in humans is unknown.

Review: Matured Hop Extract May Reduce Belly Fat.

Article: Matured hop extract reduces body fat in healthy overweight humans: a randomized, double-blind, placebo-controlled parallel group study.

Summary: This randomized controlled trial examined the effects of supplementing with matured hop extract on body weight and belly fat.

The study found that matured hop extract caused a slight loss of belly fat, compared with a placebo.

New Research From Around the World

Lots of new papers came to our attention this week. Here are summaries of the most interesting or relevant studies, categorized by subject.

1. Obesity and Weight Loss

Administration of Antibiotics to Children Before Age 2 Years Increases Risk for Childhood Obesity.

For decades, antibiotics have been used to promote weight gain in livestock. It is unclear if they have a similar effect in humans.

This observational study in children showed that three or more courses of antibiotics before the age of two were linked with an increased risk of obesity at age four.

Antibiotic Exposure During the First 6 Months of Life and Weight Gain During Childhood.

Previous animal experiments show that exposure to antibiotics early in life promotes weight gain through its effects on the gut microbiota. Observational studies in humans have provided inconsistent results.

This observational study suggests that taking antibiotics during the first six months of life does not predispose children to weight gain up to age seven.

School breakfast and body mass index: a longitudinal observational study of middle school students.

This observational study in children showed that eating breakfast at school was linked with a lower risk of obesity. The same applied to children who had two breakfasts each weekday.

2. Metabolic Syndrome

The Intestinal Immune System in Obesity and Insulin Resistance.

Growing evidence indicates that the gut microbiota and the intestinal immune system may be involved in the development of metabolic disease, obesity and insulin resistance.

This review discusses the possible links between intestinal immunity, obesity-related insulin resistance and metabolic disease.

3. Blood Sugar Control and Diabetes

Adherence to the DASH and Mediterranean diets is associated with decreased risk of gestational diabetes mellitus.

This observational study found that adhering to the DASH diet or the Mediterranean diet is associated with a reduced risk of developing diabetes during pregnancy.

Rye-Based Evening Meals Favorably Affected Glucose Regulation and Appetite Variables at the Following Breakfast; A Randomized Controlled Study in Healthy Subjects.

This randomized controlled trial showed that eating whole rye kernel bread late in the evening improved blood sugar control at the following breakfast, compared to eating bread made of white wheat flour.

What’s more, eating whole rye kernel bread reduced subjective appetite ratings, suggesting that it may be useful for those trying to lose weight.

Consumption of dairy foods in relation to impaired glucose metabolism and type 2 diabetes mellitus: the Maastricht Study.

This observational study suggests that eating lots of low-fat and fermented dairy products improves blood sugar metabolism.

Additionally, high total dairy intake was linked with a reduced risk of developing type 2 diabetes, whereas high intake of full-fat dairy was linked with an increased risk of type 2 diabetes.

Effect of multi-strain probiotics (multi-strain microbial cell preparation) on glycemic control and other diabetes-related outcomes in people with type 2 diabetes: a randomized controlled trial.

This randomized controlled trial in people with type 2 diabetes showed that supplementing with multi-strain probiotics for three months modestly improved fasting insulin and glycated hemoglobin (HbA1c), a marker of blood sugar control.

4. Heart Health

Greater flavonoid intake is associated with improved CVD risk factors in US adults.

Flavonoids are a large group of antioxidants found in virtually all plant-derived foods, especially fresh vegetables, fruits, legumes and whole grains.

This observational study suggests that a high intake of flavonoid-rich foods improves heart disease risk factors in US adults. These associations were moderate in strength.

5. Cancer

Consumption of Red/Processed Meat and Colorectal Carcinoma: Possible Mechanisms Underlying the Significant Association.

Observational and experimental studies suggest that diets high in red or processed meat are linked with an increased risk of colon cancer.

This scientific review discusses the potential mechanisms underlying these associations.

6. Brain and Mental Health

Sugar-sweetened soft drinks are associated with poorer cognitive function in individuals with type 2 diabetes: the Maine–Syracuse Longitudinal Study.

This observational study suggests that drinking a lot sugar-sweetened soft drinks may worsen mental performance in people with type 2 diabetes.

Higher dietary diversity is related to better visual and auditory sustained attention.

This observational study in Iranian women indicates that eating lots of different foods, or a high Dietary Diversity Score (according to FAO), is linked with better attention.

7. Liver Health

High serum carotenoids are associated with lower risk for developing elevated serum alanine aminotransferase among Japanese subjects: the Mikkabi cohort study.

This observational study in Japanese adults suggests that high circulating levels of pro-vitamin A carotenoids may help prevent the early development of non-alcoholic liver disease.

Low vitamin D levels and non-alcoholic fatty liver disease, evidence for their independent association in men in East China: a cross-sectional study (Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China)).

This observational study in Chinese adults suggests that high circulating levels of vitamin D may protect against non-alcoholic fatty liver disease.

8. Kidney and Urinary Health

The effects of high-dose vitamin E supplementation on biomarkers of kidney injury, inflammation and oxidative stress in patients with diabetic nephropathy: a randomized, double-blind, placebo-controlled trial.

This randomized controlled trial in patients with diabetic kidney disease showed that supplementing with vitamin E, 1200 IU/day for 3 months, reduced oxidative stress and inflammation, and had positive effects on markers of kidney injury.

Coffee and tea consumption in relation to estimated glomerular filtration rate: results from the population-based longitudinal Doetinchem Cohort Study.

Glomerular filtration rate (GFR) is a measure of how much blood is flowing through the kidneys’ filtering system. It is often used to estimate how well the kidneys are working.

This observational study found that drinking coffee was linked to a slightly elevated GFR. However, the study’s authors concluded that moderate coffee consumption is unlikely to be a concern for kidney health.

9. Muscles and Physical Performance

Effects of mate tea consumption on muscle strength and oxidative stress markers after eccentric exercise.

Mate tea is a beverage made by steeping yerba mate leaves in water. Yerba mate is a South American plant that is rich in caffeine and antioxidants.

This small, randomized, crossover trial found that drinking mate tea sped up strength recovery after eccentric strength training. It also increased the amount of antioxidants in the bloodstream.

10. Women’s Health

Dietary supplements for pain during menstruation.

This Cochrane review discusses the effectiveness of supplements for treating period pain. Most of the available studies come from Iran, where researchers have examined a variety of herbal medicines and non-herbal supplements.

Limited evidence suggests that fenugreek, ginger, valerian, zataria, zinc sulfate, fish oil and vitamin B1 may reduce period pain. None of the evidence is strong and most of the studies are small and low-quality.

11. Vitamins, Minerals and Other Nutrients

Beta-palmitate – a natural component of human milk in supplemental milk formulas.

This review discusses the health benefits of beta-palmitate in breast milk, and its importance as a constituent of supplemental milk formulas for infants.

Beta-palmitate is a type of fat that may have benefits for fatty acid metabolism, calcium absorption, bone mineral density and stool consistency. Additionally, it promotes the development of a healthy gut microbiota.