AJCN Mar, 2012 – Details The most exciting articles in the American Journal of Clinical Nutrition (AJCN) this month:

THE GOOD: 1. The best dietary choice is drinking green tea! 5 cups of green tea daily are even better than 4.Design: We conducted a prospective cohort study in 13,988 Japanese individuals aged ≥65 y. The 3-y incidence of functional disability was 9.4% (1316 cases). The multiple-adjusted HR of incident functional disability was 0.90 among respondents who consumed 1–2 cups green tea/d, 0.75 for those who consumed 3–4 cups/d, and 0.67 for those who consumed ≥5 cups/d in comparison with those who consumed <1 cup/d.

2. Eating dark chocolate or cocoa is great for your health. Insulin resistance was improved by chocolate or cocoa due to significant reductions in serum insulin. Flow-mediated dilatation (FMD) improved after chronic and acute intakes.

3. Breastfeeding lowers infant obesity at 12 months of age. 4. Assertive and intrusive maternal feeding increases child adiposity. Assertive prompting and an intrusive style had small but significant associations with greater child adiposity. 5. Kids avoiding sweets/carbs get better nutrition. Children and adolescents who consume more low carb foods are more likely to meet most nutrient recommendations than those consuming higher Glycemic Index diets.

6. PUFA (polyunsaturated fats) intake reduces colorectal cancer risk 33%. Colorectal cancer is the second leading cancer-related death in the US. Higher intakes of marine-derived n−3 PUFAs are associated with lower risk of adenomatous polyps in women.

7. Extra riboflavin (1.6mg/day) lowers BP 10 points for 10% of people. Optimizing riboflavin status offers a low-cost targeted strategy for managing elevated BP in this genetically at-risk group.

THE BAD: 8. Alcoholism is 50% heritable. Whereas moderate drinking may have health benefits, excessive alcohol consumption causes many important acute and chronic diseases and is the third leading contributor to preventable death in the United States. Twin studies suggest that alcohol-consumption patterns are heritable (50%).

9. High salt intake increases cardiovascular risk factors. Evidence links dietary sodium to hypertension and cardiovascular disease (CVD), but investigation of its influence on cardiovascular function is limited. Conclusions: Habitual dietary sodium is inversely associated with CFR independent of CVD risk factors and shared familial and genetic factors. Our study suggests a potential novel mechanism for the adverse effects of dietary sodium on the cardiovascular system.

10. 62% of people over 64 years old in England were vitamin B-12 deficient. An age-related deterioration of vitamin B-12 status is evident in the UK population. The proportion of men and women with a plasma vitamin B-12 concentration <200 pmol/L increases from ∼23% in the adult population (1) to 62% in men and women aged ≥65 y (2). Poor vitamin B-12 status is associated with anemia, peripheral neuropathy, and cognitive impairment.

11. Celiac disease. Celiac disease (CD) is an immune-mediated systemic disorder elicited in genetically susceptible individuals by wheat gluten and related proteins of barley and rye, also known as prolamines for their high content of glutamine (30–40% of total amino acids) and proline (15–20% of total amino acids). The adaptive CD4+ T cell response to gluten has a major role in the pathogenesis of damage to the small intestine.

THE UGLY: 12. Processed 4 legged meat increases diabetes risk 63%, spam doubles risk. Intake of processed meat was associated with a higher risk of incident diabetes (OR: 1.63), after adjustment for potential confounders. The relation was particularly strong for spam (OR for the comparison of upper and lower quartiles: 2.06).

13. Average US adult (40-69 yrs old) gains 1 to 2 pounds per year, about half during the winter holidays. Sixty-five percent of men and 58% of women gained ≥0.5 kg BW, with ∼50% of both groups gaining ≥1% of preholiday BW. Obese men (BMI ≥30) gained more BW than did obese women.

14. Why sodas make people fat. [Our appetites and stomachs are satified by solid but not liquid calories.] Oral-liquid and perceived gastric-liquid preloads elicited greater postprandial hunger and lower fullness sensations, more rapid gastric-emptying and orocecal transit times, attenuated insulin and glucagon-like peptide 1 release, and lower ghrelin suppression than did responses after oral-solid and perceived gastric-solid treatments. 15. Eliminating caloric sodas for 6 months caused more than 2% weight loss.

INSIGHT: 16. Insight into interpretation of nutrition research. Evidence from observational studies shows that some dietary factors, such as sugar-rich soft drinks, refined high–glycemic index carbohydrates, and energy-dense, fat-rich fast foods, are associated with increased risk of weight gain and the development of overweight and obesity, whereas diet sodas, whole-grain and low–glycemic index carbohydrates, and protein-rich foods may decrease the risk. Many scientists believe that diet composition is an ineffective tool, that we simply need to exert willpower to prevent overeating, and that we should find alternative mechanisms to explain the obesity epidemic (eg, sedentary lifestyle, stress, shortened sleep, undesirable gut microbiota). The best evidence is thought to be gained from randomized, double-blind, placebo-controlled studies, but these cannot be fully implemented in dietary studies for several reasons…An important conclusion [from one major dietary study], which received worldwide media attention, was that it does not matter for weight loss which macronutrients a diet is composed of—it is all about reducing calorie intake… [However], in reality, the low- and high-protein groups consumed diets with the same protein content, and therefore the results do not support conclusions about the impact of protein on body fat loss.

– Roc, Nutrition Investigator

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