A study published July 13, 2021 in the Journal of Nutrition examined how both whole and refined grain intake over time impacted five different heart disease risk factors: blood pressure, blood sugar, waist size, HDL level (the "good cholesterol"), and triglyceride levels. This study examined these factors in middle-to older-aged adults over the years from 1991 - 2014. The researchers found that adults who ate at least 3 servings of whole grains every day had smaller increases in blood pressure, blood sugar, and waist size over time when compared to adults who ate less than a half serving daily. There were around 3100 participants in this long-term study, mostly white and in their mid-50's, on average, at the start of the study. The five factors were evaluated every four years and included four different whole grain intake categories, ranging form 3 servings daily to the lowest half serving per day.
The same study also looked at the five risk factors across four categories involving intake of refined grains, ranging from a low of less than 2 servings daily to over 4 servings per day. Those participants who had lower refined grain intake showed a lower average waist size increase and a higher decline in triglyceride levels at each 4 year interval when compared to those consuming more than 4 servings per day.
When looking at the data, the most common whole grain foods were whole-wheat breads and whole-grain breakfast cereals, while the refined grains were mostly white bread and pasta. The whole grains are less processed, leading to a high fiber content and inclusion of antioxidants, B vitamins, and even healthy fats in small amounts. Refining these grains leads to the overly processed foods that are stripped of the nutrients and leave behind only high-starch refined grains. Sadly, the average American consumes around 5 servings of refined grains each day, well above any healthy amount. And honestly, there really isn't a healthy amount of refined grains.
So what is the takeaway? Eat more whole grains! If you currently eat refined grains every day, find ways to slowly change to whole grains. Eat a whole grain cereal in the morning instead of that donut or bagel. If you eat a lot of pasta, cut back and add whole grain options instead. These kinds of changes will keep you healthier in the long run, and thinner too.
