Research Roundup

Noteworthy nutrition studies highlighted by members of The Chan School’s Department of Nutrition

1) Cardel M, Lema DJ, Jackson KH, et al. (2015) Higher intake of PUFAs is associated with lower total and visceral adiposity and higher lean mass in a racially diverse sample of children. Journal of Nutrition 145(9): 2146-52.

We know that eating a diet with adequate intake ofSONY DSC  polyunsaturated fats is important, but new finding suggest this may have important benefits for children.

  • In recent cross-sectional study of 311 US children between the ages of 7 and 12, children who ate the highest amount of polyunsaturated fats (both omega-3 and omega-6) had more lean body mass, a lower percentage of body fat, and less intra-abdominal fat.
  • Children also had a significantly lower body fat percentage and less intra-abdominal fat if they consumed more polyunsaturated fat than saturated fat. For this reason, keeping in mind sources of both of these types of dietary fat while preparing meals is key.
  • Cooking with olive oil, soybean oil, and other liquid vegetable oils, and providing your children with snacks like walnuts, peanut butter, or avocados may help a child minimize body fat and maximize lean muscle.

2) Fung TT, Pan A, Hou T, et al. (2015) Long-term change in diet quality is associated with body weight change in men and women. Journal of Nutrition 145(8): 1850-6.

We all know the importance of a healthy diet, but a recent study that included men and women from three different cohorts – the Nurses’ Health Studies I and II, and the Health Professionals Follow-Up Study – provided further support for that point when they investigated the effect of following one of three different healthy dietary patterns on weight change over time.

  • The investigators examined changes in adherence to three dietary patterns: a Mediterranean-type diet, a diet following the Healthy Eating Pyramid (Alternate Healthy Eating Index-2010), or the Dietary Approaches to Stop Hypertension (DASH) diet. All of these diets emphasize a high intake of fruits and vegetables, whole grains, and nuts.
  • Improvements in diet quality were associated with less weight gain over time among both men and women.
  • The benefits of improving diet quality were more profound among those who were overweight and obese compared to those who were of normal weight, and among women less than 55 years of age.
  • The importance of increasing physical activity along with diet quality was also examined, and those who had the highest amounts of physical activity along with an improved diet experienced the least amount of weight gain over time.
  • The findings of this study add further evidence that increasing intake of fruits, vegetables, whole grains, and nuts and lowering intake of refined grains, sweets, and red and processed meats will help keep weight in control.

3) Chew EY, Clemons RE, Agron E, et al. (2015) Effect of omega-3 fatty acids, lutein/zeaxanthin, or other nutrient supplementation on cognitive function: The AREDS2 randomized clinical trial. JAMA 314(8): 791-801.

Evidence from observational studies has suggested that omega-3 long-chain polyunsaturated fatty acids such a DHA and EPA may reduce cognitive decline, and that antioxidants such as lutein and zeaxanthin may have similar benefits.

  • However, the AREDS2 (Age-Related Eye Disease Study 2) study, a double-blind randomized clinical trial, found no significant differences in cognitive function over the course of the study between those who received supplementation – of omega 3s, lutein and zeaxanthin, or a combination of both – when compared to those who received no supplementation.
  • This may be because the study participants were, on average, already 72.7 years old, and the supplementation may have been initiated too late in the aging process or because the duration of the study – 5 years – may not have been long enough to see a significant effect from supplementation.

This month’s Research Roundup was compiled by Nathalie Marchand, a third year doctoral student who has been researching the many effects of diet on diseases of aging, such as osteoarthritis and dementia.