Study under review: Whole grain cereals for the primary or secondary prevention of cardiovascular disease
Whole grains are touted as the definitively healthier choice when compared to refined grains. The U.S. Dietary Guidelines advise people to get 50% of their grains from whole grain sources as part of a healthy diet. Eating whole grains has been associated with weight management, prevention of diabetes, and improved heart health. As shown in Figure 1, it’s also been associated with mortality. In fact, the FDA approved some food packaging health claims stating an association between whole grain intake and better cardiovascular health. The idea that whole grains are heart healthy is repeated so frequently that it seems intuitive.
Whole grains have healthful components shown to have an effect on surrogate markers for heart disease, including viscous fiber such as β-glucans, which is found in oats and barley and lowers serum LDL levels by increasing fecal excretion of bile acids. The fiber also possibly contributes to the positive effect of whole grains on glycemic control, though the evidence on this is mixed.
However, advice to increase whole grain intake for heart health stems not from biochemical, but epidemiological research, which shows whole grain intake associated with lower heart disease risk. While epidemiology is important to the study of nutrition, randomized controlled trials (RCTs) in humans are needed to establish a causal link between increased whole grain intake and protection from cardiovascular disease.
In the study examined here, authors pooled data from all qualifying RCTs testing the effects of whole grains on cardiovascular disease or cardiovascular disease risk markers. Their goal, as part of a Cochrane review, was to assess the quality and quantity of experimental evidence that exists on this issue.
Whole grains are widely believed to be beneficial to health, particularly cardiovascular health. Most advice recommending high intakes of whole grains is based on epidemiological evidence, which links higher intake of whole grains with lower rates of cardiovascular disease. There is less experimental evidence to back up health claims for whole grains, however. In the study examined here, authors conducted a meta-analysis on existing experimental data looking at whole grain intake and heart disease.
Other Articles in Issue #37 (November 2017)
Interview: Matt Stranberg, MA, RD, CSCS
In this interview, we chat with Matt about the utility of personal genomics for nutrition, how to keep up with nutrition research, what leads to successful dieting, and much more.
Interview: Mike Howard
Personal trainer and mindset performance coach Mike Howard shares his wisdom on how to stick with goals, his thoughts on Whole30, and more.
Aspartic acid on trial: no, it doesn’t boost testosterone
The evidence for D-aspartic acid boosting testosterone has been mixed. This trial used a high dose for a longer time to help settle the matter.
Vitamin D for athletes
Even athletes are subject to vitamin D deficiency. How much do they need to reach sufficiency, and does vitamin D supplementation have an effect on performance?
Can riboflavin reduce muscle soreness?
Most research on riboflavin in athletics has focused on its effects on performance. Its effect on recovery are less well studied.
Can magnesium supplementation reduce cardiovascular disease risk factors in people with diabetes?
Observational, mechanistic, and animal evidence suggests that magnesium deficiency could raise the risk of CVD and diabetes. Could supplementation help?
Is exercise enough to improve the metabolic syndrome?
Diet and exercise combined can make an impact on factors of the metabolic syndrome. But could exercise by itself be enough to make a meaningful improvement?