Past Week in Nutrition Science: This is an overview of interesting nutrition studies published from Friday, Nov 13th, to Friday, Nov 20th.
Past Week in Nutrition Science (Nov 13th–Nov 20th)
This week, we reviewed two articles: one published in PLoS One, and the other from the International Journal of Obesity.
Science of Diet Review: Everything in Moderation: Helpful or Harmful Advice?
Summary: This was an observational study that examined how dietary diversity or quality is linked with the risk of weight gain and diabetes.
The study doesn’t support the idea that eating many types of food promotes better health. It suggests that people should focus on dietary quality, rather than diversity.
Science of Diet Review: Slow Down! Eating Too Fast May Cause Weight Gain.
Summary: This was a meta-analysis of observational studies examining the association between the speed of eating and obesity.
The study concluded that eating quickly may increase the risk of weight gain and obesity. However, randomized controlled trials are needed to confirm this findings.
New Research From Around the World
Currently, we follow over 100 journals in the field of nutrition and medicine, sifting through the headlines and bringing you summaries of the most interesting papers.
As usual, we organize the week’s selection by subject.
- Obesity and Weight
- Diabetes and Blood Sugar Control
- Heart Health
- Fitness, Diet and Sleep
- Women’s Health
- Brain and Mental Health
- Digestive Health
- Kidney Function
- Inflammation and Blood
- Vitamins, Minerals and Other Nutrients
Obesity and Weight
This prospective observational study suggests that adhering to the Nordic diet or the Mediterranean diet, at one point, does not predict future changes in body weight or waist circumference.
This rat study showed that yogurt sweetened with saccharin caused greater weight gain, compared to non-sweetened yogurt. This was despite a similar calorie intake.
This finding suggests that saccharin may lead to greater weight gain, without increasing calorie intake. There were no differences in leptin, peptide YY or insulin resistance between groups. However, the results need to be confirmed in humans.
Diabetes and Blood Sugar Control
This 2-week controlled crossover trial in people with pre-diabetes indicates that taking 30 grams of inulin per day may improve insulin sensitivity, compared to an equal amount of cellulose.
Supporting previous studies, these findings suggest that fermentable carbs, such as inulin, may help treat type 2 diabetes.
This randomized controlled trial showed that drinking 200 ml of probiotic soy milk each day, for 8 weeks, improved antioxidant status and decreased DNA methylation in type 2 diabetics. This indicates that probiotics may help treat type 2 diabetes.
This scientific review concludes that replacing saturated fat or trans fat with high-oleic acid oil may benefit the blood lipid profile and reduce the risk of heart disease. Omega-6 polyunsaturated fats may have similar effects.
This scientific review discusses the evidence about the beneficial effects of nutrients on the blood lipid profile. These include polyphenols, plant proteins, soluble fiber, monounsaturated fat and polyunsaturated fat.
This study indicates that a diet rich in plant protein may reduce heart disease risk, compared to a diet high in animal protein. However, this review also shows that the evidence supporting this is inconclusive.
This mouse study indicates that a high-fat diet may have negative effects on red blood cells. In turn, these cells may promote the development of heart disease.
Previous studies have shown that inflammation contributes to atherosclerosis. This observational study indicates that a pro-inflammatory diet may raise the risk of atherosclerosis, compared to an anti-inflammatory diet.
This small randomized trial compared the health effects of an energy drink and a placebo drink. The energy drink contained caffeine, taurine, and extracts of guarana seed, milk thistle and ginseng root.
After drinking the energy drink, blood pressure increased temporarily by an average of 6.4%. The authors suggested that these changes may promote an increased risk of heart disease.
This observational study suggests that adhering to the Mediterranean diet may reduce the risk of heart disease in Eastern European populations.
This scientific review concludes that consuming docosahexaenoic acid (DHA), which is an essential omega-3 fatty acid, may be useful in preventing non-alcoholic fatty liver disease (NAFLD). This, in turn, may reduce the risk of liver cancer.
This scientific review suggests that vitamins A, C, D, E and K may help treat pancreatic cancer. However, this needs to be confirmed in clinical trials before any strong conclusions can be made.
The favourable effects of long-term selenium supplementation on regression of cervical tissues and metabolic profiles of patients with cervical intraepithelial neoplasia: a randomised, double-blind, placebo-controlled trial.
Cervical intraepithelial neoplasia is the abnormal growth of cells on the surface of the cervix. A small amount of cases may turn into cervical cancer, if left untreated.
This randomized controlled trial found that selenium supplements — 200 mcg daily for 6 months — may help treat this condition.
This mouse study suggests that alpha-linoleic acid (ALA) may help prevent breast cancer.
This observational study indicates that a high intake of soy foods, or dietary isoflavones, may reduce the risk of colorectal cancer — especially rectal cancer.
Leukemia is a type of cancer that starts in bone marrow, causing abnormal numbers of white blood cells. This observational study in Chinese adults suggests that drinking green tea every day may reduce the risk of leukemia.
Fitness, Diet and Sleep
This review concludes that coffee, containing 3 to 8.1 mg/kg of caffeine, may temporarily help improve endurance performance.
This systematic review discusses the results of 7 randomized controlled trials, and one observational study, comparing the effects of vegetarian and omnivorous diets on physical performance.
It concludes that vegetarian diets did not improve or worsen physical performance in athletes, compared to omnivorous diets.
This observational study showed that organic food consumers in France were more likely to be vegetarian.
Organic food consumers had a lower risk of type 2 diabetes, heart disease and hypertension, but this only applied to men. Conversely, organic food consumers were more likely to report food allergies.
Obstructive sleep apnea is a common condition that is associated with snoring, pauses in breathing and sleep disturbances, leading to daytime fatigue.
This 16-week randomized trial shows that moderate calorie restriction may reduce the severity of obstructive sleep apnea.
Premenstrual syndrome may occur one or two weeks before women have their period. The symptoms include anxiety, insomnia, fatigue, headache, emotional sensitivity and mood swings.
This observational study suggests that the Western dietary pattern may increase the risk of premenstrual syndrome.
Polycystic ovary syndrome is a group of adverse symptoms caused by a hormonal imbalance in women. The symptoms may include irregular or no periods, acne and excess body hair.
This observational study indicates that going on a diet, especially a diet that is nutritionally inadequate, may increase the risk of polycystic ovary syndrome.
This observational study suggests that vitamin D deficiency during pregnancy may decrease the birth weight of the child. Additionally, women who were vitamin D deficient were more likely to become diabetic during pregnancy.
This observational study indicates that high body mass index before pregnancy, and high weight gain during pregnancy, may increase the risk of infant death. However, very low weight gain during pregnancy was also a risk factor.
This observational study found that obese, postmenopausal women had a higher bone mineral density and a lower risk of osteoporosis, compared to lean women.
The risk of fractures was significantly associated with higher age, lower body weight, lower bone mineral density and vitamin D deficiency.
Brain and Mental Health
This experimental study indicates that women are more attracted to the body odor of men who have recently eaten garlic, compared to those who haven’t.
This study suggests that those who generally like bitter-tasting foods and drinks are more likely to have antisocial personality traits.
This randomized controlled trial showed that drinking natural mineral water, rich in magnesium sulfate and sodium sulfate, reduced constipation and improved regularity, compared to a placebo.
This review discusses the potential of using probiotics in the treatment of chronic kidney disease. Test-tube experiments and animal studies have provided some promising evidence, but clinical trials are still lacking.
This mouse study indicates that too much vitamin D may have adverse effects on kidney function.
Inflammation and Blood
C-reactive protein (CRP) and interleukin-6 (IL-6) are inflammatory markers involved in the development of heart disease, type 2 diabetes and metabolic syndrome.
This scientific review discusses the association of CRP and IL-6 and dietary factors. The Mediterranean diet appears to be very effective against inflammation. The DASH diet and vegetarian diets may also be beneficial.
Myelodysplastic syndrome is a group of diseases that adversely affect the production of blood cells in bone marrow.
This observational study in Chinese adults suggests that a high intake of isoflavones, which are found in high amounts in soy foods, may reduce the risk of myelodysplastic syndrome.
Vitamins, Minerals and Other Nutrients
This study estimated the dietary intake of choline in Europe and identified its main dietary sources. The average daily intake of choline in adults was 291–468 mg. The main dietary sources of choline were meat, milk, grains, eggs and fish.
This study in US adults indicates that linoleic acid (LA) in fat tissue has increased by 136%, on average, during the last half century. This is linked to an increase in dietary LA, but the health implications are unclear.