Oats

A healthy diversity of gut microbiota is associated with numerous health benefits. To see how processing grains relates to the microbiome in animals, researchers analyzed the gut microbiota of pigs after feeding them whole grain barley and oats, or extruded whole grain barley and extruded oats. Extrusion is a process used to make pasta, cereal, croutons, and other grain products, by sending a flour and water mixture through a die to get uniform shapes. The gut microbiota of pigs eating the extruded grains showed less diversity and less presence of the microbes associated with health. The researchers concluded that “cereal extrusion affects the microbiota composition and diversity towards a state generally thought to be less beneficial for health.”
Food & Function. 2016 Feb;7(2):1024-32. (Moen B et al.)

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.)

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 grains (like rye, oats, and whole wheat) have a strong history in traditional Scandinavian cuisine, but as in other regions, the food landscape is changing and refined grains have replaced some traditional foods. To see how eating whole grains relates to mortality, researchers analyzed the diets of over 120,000 people in Denmark, Norway, and Sweden.  The scientists found that those who ate the most whole grains had significantly lower risk of death from all causes. When analyzing individual whole grains, the researchers found significantly lower mortality rates in those who ate the most whole grain breakfast cereals, whole grain bread, oats, rye (only statistically significant for men), and whole wheat. These findings support existing evidence that whole grains may contribute to longevity.
British Journal of Nutrition. 2015 July 23:1-16. (Johnsen NF et al.) [Epub ahead of print]