Low-Fat Foods And Eating Dairy Review
As usual, we reviewed two articles this week. One was published in Nutrition & Diabetes, while the other appeared in the British Journal of Nutrition.
Summary: This study found that reduced-fat or fat-free foods contain greater amounts of sugar than their full-fat versions.
Summary: This was a systematic review and meta-analysis of observational studies examining the association of dairy products and heart disease.
The study suggests that eating dairy products may reduce the risk of heart disease, coronary heart disease and stroke.
New Research From Around the World
Tons of new research came out this week. We have selected the most interesting or relevant papers and categorized them by subject.
- Obesity and Weight Loss
- Metabolic Syndrome
- Blood Sugar Control and Diabetes
- Heart Health
- Appetite and Eating
- Brain and Mental Health
- Digestive Health
- Kidney Health
- Bone Health
- Muscles and Physical Performance
- Women’s Health
- Longevity and Healthy Aging
- Nutrients, Vitamins and Minerals
1. Obesity and Weight Loss
This observational study suggests that better vitamin D status from infancy to age three is associated with a reduced risk of weight gain and obesity.
This review indicates that eating breakfast may help prevent excessive weight gain and obesity in children and adolescents. However, the quality of the evidence is poor, and higher-quality studies are needed.
This observational study indicates that dairy consumption reduces the risk of excessive weight gain and obesity among children.
2. Metabolic Syndrome
Retinoic acid is the active form of vitamin A in the body.
This observational study in Chinese people suggests that high circulating levels of retinoic acid may reduce the risk of metabolic syndrome, independently of obesity and insulin resistance.
Obesity and insulin resistance are linked with chronic inflammation in fat tissue and the liver. Emerging evidence suggests that this inflammation may be mediated by the gut microbiota.
For this reason, some scientists have speculated that the gut microbiota may be responsible for the inflammation in obesity and metabolic syndrome. This review takes a look at the evidence.
3. Diabetes and Blood Sugar Control
This randomized controlled trial showed that eating either fish or meat before a rice dish helped improve blood sugar control.
This systematic review and meta-analysis indicates that light and moderate alcohol consumption may lower the risk of type 2 diabetes. On the other hand, heavy drinking was not associated with type 2 diabetes.
This randomized, crossover trial found that eating khorasan wheat reduced fasting levels of LDL-cholesterol, insulin and glucose. In comparison, eating products made from modern, semi-whole wheat flour did not improve any of these health factors.
This randomized, crossover trial compared the effects of two types of fiber-rich breads that differed in their fiber particle sizes. To obtain bread with high fiber particle sizes, the researchers replaced some of the flour with broken wheat kernels.
Blood sugar increased similarly after both types of bread. However, the increase in glucagon-like peptide-1 (GLP-1) was much lower after the kernel bread. GLP-1 is a hormone that promotes insulin production and sensitivity.
This randomized, controlled trial in women with polycystic ovary syndrome examined the effects of meal frequency on blood sugar and insulin levels. It showed that six meals per day improved the results of an oral-glucose tolerance test.
Conversely, meal frequency did not have any effects on blood sugar, HbA1c, blood lipids, appetite or satiety.
4. Heart Health
This observational study suggests that low to moderate alcohol consumption may improve the blood lipid profile.
Endothelial function refers to the condition of the inner lining of the blood vessels. When the endothelium is dysfunctional, the tiny muscles lining the blood vessels make them either too narrow or too dilated.
This systematic review and meta-analysis concludes that supplementing with vitamin D does not improve endothelial function.
This observational study in Malaysian adolescents suggests that drinking lots of sugar-sweetened beverages may impair heart health.
Acute benefits of the microbial-derived isoflavone metabolite equol on arterial stiffness in men prospectively recruited according to equol producer phenotype: a double-blind randomized controlled trial.
Daidzein is an isoflavone found in soy products. In the colon, daidzein is changed into equol by intestinal bacteria. However, this only happens in about 30% of people in Western countries, since specific types of equol-producing bacteria are required.
Equol has been associated with several health benefits. This randomized controlled trial showed that eating soy reduced the stiffness of arteries in equol-producers. Reduced arterial stiffness is associated with a lower risk of heart disease.
Atrial fibrillation is a type of abnormal heart rhythm (arrhythmia), characterized by fast or irregular heartbeats. It is a risk factor for stroke and heart attacks.
This observational study suggests that eating a lot of fish or omega-3 polyunsaturated fats does not protect against atrial fibrillation. However, high consumption of lean fish was associated with a lower risk.
Taurine is an organic acid found in animal products, such as fish, meat and dairy. This randomized, controlled trial in people with moderately elevated blood pressure (pre-hypertension) showed that supplementing with taurine reduced blood pressure.
This observational study in overweight and obese individuals suggests that being overweight reduces the risk of death after a heart attack.
A similar association has been reported before, and is called the obesity paradox. However, this is controversial and not all previous studies agree.
This observational study indicates that eating a lot of antioxidant-rich foods may reduce the risk of aggressive prostate cancer.
Visceral obesity refers to the excessive accumulation of fat inside the abdominal cavity. This observational study indicates that high levels of visceral obesity may reduce survival among patients with pancreatic cancer.
This observational study shows that circulating levels of vitamin D are low in Tunisian patients with bladder cancer.
One-carbon metabolism is a process involved in the repair and synthesis of the genetic code (DNA), and the control of gene expression. Several nutrients are essential in this process. These include folate, vitamin B12, B6, B2 and choline.
This observational study examined whether any of these nutrients reduce the risk of pancreatic cancer. The findings suggest that higher intake of vitamin B6 and choline may be protective.
6. Appetite and Eating
Many French consumers add sugar to sweeten plain yogurts before they eat them. The participants in this study added 13.6 grams of sugar to their yogurt, on average.
This is higher than the 10.2 grams (per 125 grams) manufacturers usually add to their sugar-sweetened yogurts. The study also showed that consumers underestimate the amount of sugar they use.
This experiment examined people’s brain activity when they were looking at foods that differed in their calorie content or availability.
The study showed that high-calorie foods that are immediately available caused a stronger response in the reward centers of the brain, compared to lower-calorie foods, or foods that were not immediately available.
Restrained eating refers to abstaining or avoiding certain foods, ingredients or food groups. On the other hand, external eating refers to the inability to resist certain foods when they are immediately available.
This study showed that weight stigma and body dissatisfaction were associated with restrained eating and external eating in elementary school girls. Body dissatisfaction also had similar effects on restrained eating in boys, whereas weight stigma did not.
This randomized, controlled trial in 24 obese men and women showed that skipping breakfast did not increase calorie intake at a subsequent pasta lunch. What’s more, it did not seem to increase appetite in the afternoon.
However, morning fasting reduced the levels of satiety hormones during the lunch. It also reduced the levels of the hunger hormone ghrelin in the afternoon.
7. Brain and Mental Health
This Cochrane review showed that most studies have not found any links between dietary antioxidant intake and schizophrenia. However, there was some evidence thatGinkgo biloba had beneficial, short-term effects on psychotic symptoms.
8. Digestive Health
Guar gum is a type of dietary fiber made from guar beans. Partially hydrolyzed guar gum (PHGG) is a well-known prebiotic fiber that increases the growth of beneficial bacteria in the colon.
This randomized, controlled trial in patients with irritable bowel syndrome showed that supplementing with PHGG, 6 grams per day for 12 weeks, significantly reduced bloating.
Titanium dioxide is used in the production of paint, plastics, paper, toothpaste, pills and tablets. It is also used as a white food colorant in products such as cheese, sauces and sweets.
This study indicates that titanium dioxide may worsen symptoms in individuals with inflammatory bowel disease.
Previous studies have shown that iron deficiency is a common problem in patients with inflammatory bowel disease (IBD). However, supplementing with iron may worsen IBD symptoms.
This randomized trial in healthy people and patients with IBD showed that supplementing with iron significantly changed the composition of the gut microbiota, especially in IBD patients. The health relevance of this is unclear.
Crohn’s disease (CD) is a type of inflammatory bowel disease, characterized by stomach pain, diarrhea and weight loss. Animal studies indicate that glutamine, an amino acid important for intestinal health, may help treat CD.
This Cochrane review concludes that studies do not support the use of glutamine supplements in people with Crohn’s disease. However, further studies are needed before any solid conclusions can be reached.
9. Kidney Health
Previous studies indicate that certain toxins, mainly indoxyl sulfate (IS) and p-cresyl sulfate (PCS), impair kidney function. What’s more, some researchers suggest that these toxins are due an imbalanced gut microbiota.
This randomized controlled trial in patients with chronic kidney disease showed that supplementing with both probiotics and prebiotics significantly reduced levels of PCS, but not IS.
10. Bone Health
This observational study indicates that sodium intake is not associated with an increased risk of fractures or osteoporosis in postmenopausal women.
11. Muscles and Physical Function
The age-related loss of muscle mass is an important health issue among older people. Previous studies have shown that increased protein intake may help maintain muscle mass, but the effects of protein on strength are less clear.
This observational study suggests that high intake of protein may help maintain grip strength in people aged 60 years or older.
Weight loss not only leads to loss of fat mass, but also muscle. However, increased protein intake may help reduce muscle loss.
This randomized trial in overweight, older adults showed that increasing protein intake above the habitual intake levels of 0.9 grams/kg/day (about 2 grams/lb/day) did not preserve lean mass or strength during a 12-week calorie-reduced diet.
12. Women’s Health
A growing number of studies indicate that certain types of fat may improve fertility in women.
This observational study showed that a high intake of omega-3 docosapentaenoic acid was associated with higher progesterone levels and a lower risk of anovulation, which is when the ovaries fail to release eggs for more than three months.
13. Longevity and Healthy Aging
This observational study showed that a greater adherence to official dietary guidelines is associated with an increased chance of healthy aging.
This observational study in 150,969 adults, aged 45 years and over, suggests that eating lots of fruit and vegetables reduces the risk of death from all causes.
Acrylamide is a contaminant classified as “probably carcinogenic” in humans. It forms in starchy foods that are exposed to high heat.
This observational study suggests that food products, such as cookies, crackers and dry cakes, are the strongest determinants of circulating acrylamide in non-smoking, postmenopausal women in Europe.
15. Nutrients, Vitamins and Minerals
This review concludes that replacing salt lost in sweat during exercise may improve physical performance, but possibly decrease the long-term health benefits of physical activity.
This review discusses the safe upper intake levels of folic acid, and the risks associated with getting too much of it.
It points out that there is evidence of neurological damage from the long-term intake of folic acid, ranging from 0.5 to 1 mg per day, in people who suffer from vitamin B12 deficiency.