Past Week in Nutrition Science: This is an overview of interesting nutrition research published from Friday, Dec 31st, 2015, to Friday, Jan 8th, 2016.
Past Week in Nutrition Science (Dec 31st–Jan 8th)
In the past week, we reviewed two articles: one from Obesity Reviews, and the other from Nutrition & Diabetes.
Summary: This was a review of the body clock’s role on weight maintenance, and how disrupting it may lead to weight gain. Abnormal sleeping patterns and irregular eating should be avoided.
Summary: This was a randomized, controlled trial examining how phosphorus supplementation affected weight loss. Supplementing with phosphorus for 12 weeks led to significant weight loss, compared to a placebo.
New Research From Around the World
Every week, we go over hundreds of recent articles published in nutrition and medical journals, selecting the most interesting and relevant ones.
Below is this week’s selection, categorized by subject.
- Obesity and Weight Loss
- Blood Sugar Control and Diabetes
- Heart Health
- Metabolic Syndrome
- Brain and Mental Health
- Appetite and Eating
- Muscles and Physical Performance
- Lung Health
- Skin Health
- Women’s Health
Obesity and Weight Loss
This study calculated the weight loss that would take place if the sugar content of all soft drinks was reduced by 40%, over a 5-year period.
The study found that body weight in British adults would, on average, decrease by 1.20 kg (2.6 lbs), reducing the prevalence of adult obesity from 35.5% to 34.5%.
This prospective, observational study of young twins examined the association of protein intake, BMI and obesity from the age of 2 to 5.
The study suggests that high protein intake at the age of 2, shortly after weaning, is associated with increased incidence of obesity when they are 3 years of age. This association was not significant when the children were 5 years old.
Blood Sugar Control and Diabetes
This meta-analysis of observational studies suggests that eating eggs does not increase the risk of type 2 diabetes.
However, eating more than 3 eggs per day, on average, may cause a modest increase in the risk of type 2 diabetes. This association was significant only in US studies, but not in other countries.
This study of obese adults indicates that physical activity is just as important as calorie restriction when it comes to improving insulin sensitivity.
Green Tea Extract and Catechol-O-Methyltransferase Genotype Modify Fasting Serum Insulin and Plasma Adiponectin Concentrations in a Randomized Controlled Trial of Overweight and Obese Postmenopausal Women.
This large, randomized controlled trial compared the effects of decaffeinated green tea extract to a placebo in overweight and obese adults.
The study found no significant differences in body weight, BMI or waist circumference across groups. However, the green tea extract reduced fasting insulin levels in those who had elevated insulin at the start of the study.
This observational study examined the association of probiotic supplementation andislet autoimmunity in children genetically predisposed to type 1 diabetes (T1D).
The study suggests that supplementing with probiotics early in life may reduce the risk of islet autoimmunity for children who have a high risk of T1D.
This randomized, controlled trial in overweight or obese adults examined the effects of drinking a beverage containing 361 mg of polyphenol antioxidants, every day for 4 weeks, on risk markers for vascular disease.
The beverage, which contained flavonoids, hydroxycinnamates and vitamin C, had no beneficial effects on risk factors for vascular disease.
This randomized, crossover trial in healthy individuals compared the effectiveness of the standard DASH diet and the high-fat, low-carb DASH diet.
The study showed that the high-fat, low-carb DASH diet lowered blood pressure similarly to the standard DASH diet.
This observational study suggests that a high intake of dairy products may reduce the risk of metabolic syndrome.
When full-fat and low-fat dairy products were investigated separately, only full-fat dairy products reduced the risk of metabolic syndrome.
This mouse study found that table sugar intake promoted breast cancer growth, compared to a placebo.
Brain Function and Mental Health
This review discusses the role of the omega-3 fats, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the prevention of major depression and Alzheimer’s disease.
This observational study in women indicates that better iron status may lead to faster reaction time and better planning ability. Conversely, better iron status was associated with worse working memory.
This observational study suggests that an unhealthy dietary pattern may increase the risk of depression during pregnancy or after delivery. An unhealthy diet was low in fish, fruit, vegetables and whole grains.
This meta-analysis of observational studies suggests that higher coffee consumption may protect against the development of Alzheimer’s disease.
This meta-analysis of observational studies indicates that eating fish may reduce the risk of dementia.
Additionally, the omega-3 fat docosahexaenoic acid (DHA) was associated with a lower risk of dementia and Alzheimer’s disease.
Isoflavones are a class of plant compounds found in legumes. This observational study suggests that higher isoflavone intake may improve sleep duration and quality in Japanese people.
Working memory is an important brain function responsible for processing new and old information (memories), and plays an essential role in learning, comprehension and reasoning. It is impaired in people with pre-diabetes.
This observational study suggests that cinnamon may improve working memory in people with pre-diabetes.
Appetite and Eating
This experiment showed that appetite, and changes in appetite after a meal, estimated using an MRI scan, are very similar in monozygotic twins.
These results suggest that at least some aspects of appetite may be inherited.
This 6-week study in obese people showed that a low-fat or a portion-controlled diet increased sensitivity to the taste of fat. This applied especially to the low-fat diet, but following these diets did not change food preferences.
These results support previous studies suggesting that excess fat intake makes people less sensitive to the taste of fat.
This experiment found that when meal portion sizes were increased, people were more likely to select foods that were of low or medium calorie density.
This small, randomized crossover study showed that eating small, frequent meals does not reduce appetite, compared to eating fewer, larger meals.
Capsaicin, found in chili peppers, has been associated with increased fullness after meals. This small, randomized controlled trial showed that the fullness is caused by digestive distress — pain, nausea and bloating.
Muscles and Physical Performance
This randomized trial showed that supplementation with branched-chain amino acids(BCAAs) helps people maintain muscle mass while on an 8-week, calorie-restricted strength exercise program.
A few studies have investigated the effects of nutrition on tendon injuries, suggesting that protein and certain amino acids may be useful. This review discusses the available evidence.
Inactivity leads to a rapid loss of muscle mass and strength, especially in older adults. Leucine is an amino acid that may help people maintain their muscle mass.
This randomized, controlled trial in middle-aged adults showed that a leucine supplement, 0.06 grams per kg of body weight, protected muscle mass during 14 days of bed rest.
This 24-week, randomized controlled trial in healthy older adults showed that supplementing with milk protein, 0.165 grams for per kg body weight, increased lean body mass by 0.45 kg, compared to a reduction of 0.27 kg in the control group.
These results suggest that supplementing with protein may help preserve lean mass, including muscle mass, in healthy older adults.
Cystic fibrosis is a genetic disorder that mostly affects the lungs, leading to difficulty breathing and frequent lung infections. It also adversely affects the digestive system, liver and kidneys.
This Cochrane review concludes that supplementing regularly with omega-3 fatty acids may benefit people with cystic fibrosis. However, there is still not enough evidence for any solid conclusions.
Cocoa is rich in antioxidants, such as flavanols. This randomized controlled trial examined the effects of drinking a cocoa beverage, containing 320 mg of cocoa flavanols, on facial wrinkles and skin elasticity.
The study showed that drinking this high-flavanol cocoa beverage for 24 weeks improved both wrinkles and skin elasticity.
Atopic dermatitis, also called eczema, is a skin condition that causes the skin to become dry and itchy. Scratching then causes it to become red, cracked and swollen.
This randomized, controlled trial found that supplementing with melatonin, 3 mg/day for 4 weeks, reduced the severity of atopic dermatitis in children. It also reduced the time it took for them to fall asleep at night.
Congenital ichthyosis (CI) is a genetic skin disorder characterized by dry, flaky or cracked skin. Severe vitamin D deficiency is very common in children with this condition.
This study shows that children with CI benefit from high-dose vitamin D supplementation. After one month, their skin had become almost normal, indicating that vitamin D supplementation may be an effective treatment for CI.
Cervical neoplasia is characterized by abnormal growth of the cells lining the cervix. It is not a cancer, but may increase the risk of cervical cancer if left untreated.
This observational study suggests that high vitamin C intake may reduce the risk of cervical neoplasia. This association was dose-dependent.
This observational study indicates that high blood levels of antioxidants, including vitamins C and E, may improve women’s reproductive health.
Pregnancy and Infant Health
This observational study shows that deficiency in red blood cells (or hemoglobin) is a major cause of ill health and death among pregnant women in developing countries. Anemia can be treated with an iron-rich diet or supplements.
Prenatal supplementation with Corn Soya Blend Plus reduces the risk of maternal anemia in late gestation and lowers the rate of preterm birth but does not significantly improve maternal weight gain and birth anthropometric measurements in rural Cambodian women: a randomized trial.
Corn Soya Blend Plus is a dietary supplement, enriched with vitamins, that helps women meet their nutritional requirements during pregnancy.
This randomized trial in pregnant Cambodian women showed that Corn Soya Blend Plus reduced the risk of anemia during pregnancy and preterm birth, compared to women who got a normal diet. However, it also increased the risk of fetal loss.