SEARCH HEALTH STUDIES

Replacing Potatoes with Whole Grains Can Lower Gestational Diabetes Risk

Healthy food choices can be an important way to help prevent gestational diabetes, a type of diabetes that occurs during pregnancy. To learn more about types of foods that might be helpful or harmful, Harvard researchers analyzed the diets and health outcomes of over 15,000 women. They found that replacing two servings per week of potatoes with whole grains lowered the risk of gestational diabetes by 12% (compared to 10% for replacing potatoes with legumes, and 9% for replacing potatoes with other vegetables).
British Medical Journal. 2016 Jan 12;h6898. (Bao W et al.)

Gluten Free Diet Has No Effect on Non-celiac Athletes

A common belief among athletes is that going gluten-free might help performance. To investigate this popular belief, Australian scientists randomly assigned 13 competitive cyclists without celiac disease to a 7 day gluten containing diet or a 7 day gluten free diet. The cyclists then went through a 10 day washout period, before trying the other diet, serving as their own controls. There was no significant difference in time trial performance of the athletes on either diet, nor were there significant differences in markers of inflammation or intestinal injury.
Medicine and Science in Sports and Exercise. 2015 Dec;47(12):2563-70.

Whole Grains for Breakfast Linked with Higher Test Scores in Elementary Students

Whole grains are a classic centerpiece to the morning meal for many families, but students may especially benefit from this practice. Researchers collected data from nearly 700 elementary school students in Kansas (average age = 7.5) to see how eating breakfast relates to standardized test scores. They found that while breakfast eaters scored significantly higher in all test areas, what the students ate made a big difference. Greater servings of whole grains were significantly related to higher scores in reading comprehension and fluency and math, while fruit juice was significantly correlated with lower math and reading comprehension and fluency scores.  
Journal of the American College of Nutrition. 2015 Dec 23:1-8 [Epub ahead of print] (Ptomey LT et al.)

Whole Grain Pasta Meal Reduces Appetite

There is more to healthy eating than just salads — whole grain pasta could be a great pick for dieters looking to curb hunger. In a small study, 8 healthy adults were assigned to a lunch of either a refined grain pasta, a refined grain pasta with lemon juice, a refined grain pasta with legumes, or a whole grain pasta – all with the same amount of calories. Each week, the participants were assigned to a different pasta meal, serving as their own controls. The researchers found that the whole grain pasta “resulted in significantly greater fullness and reduced hunger and prospective [later] food intake.” The scientists also found that whole grain pasta was just as popular among the participants as the other meals, noting that “palatability ratings did not differ.”
Applied Physiology, Nutrition, and Metabolism. 2015 Nov 16:1-7. (Cioffi I et al.)

 

 

Whole Grains Linked with Weight Loss in Children

In many parts of the developed world, approximately one third of children are overweight or obese, putting them at higher risk for health complications down the road. To determine which foods are most closely linked with excess weight gain in children, researchers analyzed the three-day food records and BMI of over 4,600 British children at ages 7, 10, and 13. Potato chips were most closely linked with excess weight gain in children, along with butter and margarine, battered or breaded fish, processed meats, French fries and roasted potatoes, desserts, and sweets. On the other hand, whole grains were the only food group to be consistently linked with weight loss, suggesting that whole grains may be particularly important for children struggling with their weight.
Health Affairs. 2015 Nov;34(11):1940-1948. (Dong D et al.)

Different Oat Products Elicit Different Glycemic Responses

The Glycemic Index is a measure of how much a food spikes your blood sugar (0-55 is low, 56-69 is medium and 70-100 is high). To see if different oat products have different effects on blood sugar, researchers from Quaker Oats tested the Glycemic Index of 72 oat products. They found that steel cut oatmeal, large flake oatmeal, muesli, and granola produced a significantly lower Glycemic Response (53-56, in the low/medium range) than quick cooking and instant oatmeal (71-75, in the medium/high range). The scientists concluded that “smaller particle size and increased starch gelatinisation appear to increase the glycemic response.”
British Journal of Nutrition. 2015 Oct 28;114(8):1256-62. (Tosh SM et al.)

Replacing Butter, Sugar, or Refined Grains with Whole Grains Cuts Heart Disease Risk

Harvard researchers followed over 120,000 adults for 24-30 years, tracking their diet and health records. The scientists found that replacing 5% of daily calories from saturated fat (like butter, cream, and red meat) with whole grains is associated with a 9% lower risk of heart disease, but replacing saturated fat with refined grains or added sugars does not lower heart disease risk. Additionally, they found that replacing 5% of daily calories from refined grains and added sugars with whole grains or polyunsaturated fats (found in fish, nuts, seeds, and safflower oil) can also significantly reduce heart disease risk. The researchers concluded, “Our findings provide epidemiological evidence of the current dietary guidelines, which recommend both “replacing saturated fatty acids with monounsaturated and polyunsaturated fatty acids” and “replacing refined grains with whole grains.””
Journal of the American College of Cardiology. 2015 Oct;66(14):1538-48. (Li Y et al.)

Whole Grains, Especially Oats, May Lower Cholesterol

Even modest reductions in cholesterol are thought to help prevent heart disease, so heart healthy diets are an important area of research. To determine the link between whole grains and cholesterol, scientists analyzed the results of 24 randomized controlled trials (totaling 2,275 participants). They found that eating whole grains is associated with lower LDL (“bad”) cholesterol and total cholesterol, with no significant effect on HDL (“good”) cholesterol or triglycerides (a type of fat in the blood). Whole grain oats specifically seemed to be linked with the greatest cholesterol lowering effects compared to other whole grain foods. The length of the study was also associated with positive changes in cholesterol, indicating health benefits are greater for those who make whole grains a regular part of their daily lifestyle.
The American Journal of Clinical Nutrition. 2015 Sept;102(3):556-72. (Hollaender PLB et al.)

Whole Grain Intake Linked with Lower Stroke Risk

It is estimated that up to 80% of strokes can be prevented, so food choices to protect against strokes are an important area of research. Scientists in China analyzed six large prospective studies following over 247,000 people to see how whole grain intake related to stroke risk. Those eating the most whole grains had a 14% lower risk of stroke than those eating the least whole grains. The authors concluded that “higher whole grain intake has a protective effect on stroke.”
International Journal of Clinical and Experimental Medicine. 2015 Sep 15;8(9):16978-83 (Fang L et al.)

Carbs (Like Whole Grains) Vital to Early Human Brains

Whole grains are important to our brain health today, but new evidence suggests that they were also vital to our brain development millions of years ago. Researchers in Europe and Australia examined diet’s role in the development of early humans, and found that carbohydrates (such as whole grains, root vegetables, and other starchy plant foods) were “necessary to accommodate the increased metabolic demands of a growing brain.” While most depictions of early human foods emphasize hunter-gatherer diets full of meat, the scientists argue that cooked starches permitted “the acceleration in brain size increase from the Middle Pleistocene onward.”
The Quarterly Review of Biology. 2015 Sept;90(3):251-268. (Hardy K et al.)

Whole Grains Offer Benefits Beyond Fiber

Whole grains are well known for their fiber; however, fiber is not the only benefit of a diet rich in whole grains. This study uses nutritional metabolomics (a field of that looks at how different foods affect metabolism) to explore how the different compounds in whole grains may affect metabolism, and suggests scientific reasons behind the health benefits of whole grains, beyond just their fiber content. Specifically, this analysis suggests that whole grains may have positive effects on insulin sensitivity and protein metabolism, and may contain other beneficial compounds, such as glycine betaine.
Proceedings of the Nutrition Society. 2015 Aug;74(3):320-7. doi: 10.1017/S0029665114001542. Epub 2014 Oct 23. (Ross AB et al.)

High Phytate Foods (Beans, Nuts, Whole Grains, etc.) May Help Young Women Better Absorb Iron over Time

Phytates are compounds found in many plant foods, especially in beans and whole grains. Although phytates are linked with health benefits, they can also block the absorption of non-heme iron (the type of iron found in beans and other plant sources). To see how eating these phytate-rich foods affects nutrition status, scientists in Iowa assigned 28 non-anemic young women to either a high phytate (lots of whole grains, beans, nuts, and tofu) or low phytate (refined grains, eggs, and cheese, avoiding high phytate foods) diet for eight weeks, then tested their iron levels. After consuming a high phytate diet for 8 weeks, there was a 41% increase in serum iron response (measured by area under the curve). This indicates that “habitual consumption of [a high phytate] diet can reduce the negative effect of phytate on non-heme iron absorption among young women with sub-optimal iron stores.”
Journal of Nutrition. 2015 Aug;145(8):1735-9. (Armah SM et al.)

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