Carbohydrate Quality and Human Health: A Series of Systematic Reviews and Meta-Analyses
Heart disease, also known as cardiovascular diseases (CVD), contributes to numerous deaths worldwide. Some of these diseases include heart attack, coronary artery disease, irregular heart rhythm, heart valve disease, and Arial Filtration. Heart disease has been partly linked to dietary fiber. With this knowledge, fiber intake can be modified to prevent or lower the risk of CVD. In the article Carbohydrate Quality and Human Health: A Series of Systematic Reviews and Meta-Analyses, Reynolds et al. (2019), reviewed and analyzed studies of dietary fiber and its influence on mortality and risk factors of non-communicable-disease including coronary heart disease.
The researchers conducted a series of systematic reviews and meta-analysis to make dietary fiber recommendations for non-communicable disease. The study involved 158 research articles and 58 clinical trials from published in PubMed, Embase, Ovid MEDLINE, and the Cochrane Central Register of Controlled Trials (Reynolds et al., 2019). To qualify for review, the studies and the clinical trials were required to report on carbohydrate quality and the risk factors as well as mortality of non-communicable diseases. The team ensured to duplicate independent searches, bias assessment, and data extraction. Also, meta-regression, subgroup analyses, dose-response testing, and sensitivity analyses was used in the random-effect models when considering the robustness of the poled estimates. A total of 4635 adult participants were featured in the studies and the clinical trials.
The team revealed that people who consumed high levels of dietary fiber had a 15 – 30% lower risk to cardiovascular incidence and mortality compared to their counterparts. They also revealed a 16- 24% risk reduction of type 2 diabetes, stroke, coronary heart disease, and colorectal cancer among the participants who consumed high amounts of dietary fiber. The results translate into 13 lesser deaths per 1,000 participants and 6 lesser incidences of coronary heart disease (Reynolds et al., 2019). Additionally, the meta-analysis of the clinical trial showed that high fiber intake reduced body weight and cholesterol, relative to low fiber intake. Specifically, an 8g intake of dietary fiber consumed per day led to a 5-27% reduction of deaths and incidences related to coronary heart disease, colorectal cancer, and type 2 diabetes. The daily consumption of 15g of whole grains was also linked to a reduction of 2-19% in total deaths and incidences of coronary heart disease, colorectal cancer, and type 2 diabetes (Reynolds et al., 2019). The meta-analysis of clinical trials further revealed that the consumption of high amounts of whole grains reduced body weight, which is a significant factor in heart disease. Lastly, the study revealed that diets with high glycaemic index and high glycaemic load had a higher probability of preventing stroke and type 2 diabetes.
The relationship between fiber intake and heart disease has been extensively studied. Although I knew about the impact of fiber on heart disease, I did not have the specific knowledge of its effect on cholesterol level and body weight. These two factors are significant in heart disease risk. The present study has helped me understand the relationship between fiber intake and heart disease deeper. The study stands out due to its ability to investigate the key indicators of carbohydrate quality in relation to the results from the randomized trials and cohort studies in a single review. The selection of the studies was also carefully done and only valid databases were used. The findings imply that dietary intake should be increased to be safe from heart disease and whole grains should be consumed more than refined grains.
Reynolds, A., Mann, J., Cummings, J., Winter, N., Mete, E., & Morenga, L. (2019, Jan 10). Carbohydrate quality and human health: A series of systematic reviews and meta-analyses. The LANCET, 393(10170), 434-445. Retrieved from https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)31809-9/fulltext