Reference Number: 686
Year: 2018
Link: Link to original paper
Health: Blood pressure
Nutrition: Whole grain
Summary
Abstract
The aim of this systematic review and meta-analysis was to summarize the evidence on the relation of the intakes of 12 major food groups, including whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSBs) with the risk of hypertension. PubMed, Scopus, and Web of Science were searched systematically until June 2017 for prospective studies having quantitatively investigated the above-mentioned foods. We conducted meta-analysis on the highest compared with the lowest intake categories and linear and nonlinear dose-response meta-analyses to analyze the association. Summary RRs and 95% CIs were estimated by using a random-effects model. Overall, 28 reports were included in the meta-analysis. An inverse association for the risk of hypertension was observed for 30 g whole grains/d (RR: 0.92; 95% CI: 0.87, 0.98), 100 g fruits/d (RR: 0.97; 95% CI: 0.96, 0.99), 28 g nuts/d (RR: 0.70; 95% CI: 0.45, 1.08), and 200 g dairy/d (RR: 0.95; 95% CI: 0.94, 0.97), whereas a positive association for 100 g red meat/d (RR: 1.14; 95% CI: 1.02, 1.28), 50 g processed meat/d (RR: 1.12; 95% CI: 1.00, 1.26), and 250 mL SSB/d (RR: 1.07; 95% CI: 1.04, 1.10) was seen in the linear dose-response meta-analysis. Indication for nonlinear relations of the intakes of whole grains, fruits, fish, and processed meats with the risk of hypertension was detected. In summary, this comprehensive dose-response meta-analysis of 28 reports identified optimal intakes of whole grains, fruits, nuts, legumes, dairy, red and processed meats, and SSBs related to the risk of hypertension. These findings need to be seen under the light of very-low to low quality of meta-evidence. However, the findings support the current dietary guidelines in the prevention of hypertension.
Summary of Findings
This study set out to answer a straightforward but important question: Which foods are linked to a higher or lower risk of developing high blood pressure (hypertension)? Although this research has some research flaws due to being based on meta-analysis, instead of running a new experiment, the researchers analysed results from many long?term population studies that followed people over time and recorded what they ate and whether they later developed hypertension.
They systematically searched the scientific literature and included 28 prospective cohort studies, covering more than 1.2 million adults. These studies tracked people for years and looked at how different food groups related to their risk of developing high blood pressure.
The researchers found clear patterns showing that certain foods are consistently linked to a lower risk of developing hypertension:
Foods associated with lower hypertension risk
- Whole grains: People who ate more whole?grain foods had a significantly lower risk of developing high blood pressure. The relationship showed a dose?response pattern — meaning the more whole grains people ate, the lower their risk tended to be.
- Low?fat dairy: Higher intake was linked to a reduced risk of hypertension.
- Vegetables and fruits: Both were associated with a lower risk, again with a dose?response effect.
- Legumes (beans, lentils, peas): Also showed a protective association.
Foods associated with higher hypertension risk
- Red meat and processed meat: Higher consumption was linked to an increased risk of developing hypertension.
- Sugar?sweetened beverages: Consistently associated with higher risk.
- Alcohol: Higher intake increased risk, especially at moderate?to?high levels.
Neutral or unclear associations
Some food groups did not show consistent or strong associations, including:
- Fish
- Nuts
- Whole-fat dairy
The authors note that differences in how studies measured diet may explain some of these inconsistencies.
Significance for the baker
Overall, the study provides evidence that dietary patterns rich in whole grains, fruits, vegetables, legumes, and low?fat dairy are linked to a lower long?term risk of developing high blood pressure. Conversely, diets high in red and processed meats, sugary drinks, and alcohol increase risk. Whilst a broad based paper, this can help the baker suggest symbiotic recipes to serve with the bread.
