Written by Marcia J. Egles, MD. This article discusses the finding that B vitamins: thiamine (vitamin B1) and folacin (folate, vitamin B-9) were associated with a decrease in blood pressure.
Dietary B vitamins may have favorable effects on blood pressure according to a “nutrient-wide” statistical study (1) published by the American Heart Association.
Hypertension, also known as “high blood pressure”, is the leading cause of heart disease worldwide (2). Risk for heart disease and stroke increases across a range of blood pressures, with substantial risk attributed to even high-normal blood pressure levels (1). Dietary habits including salt use are known to be related to blood pressure elevation (3), but the role of many nutrients is unclear despite research efforts (1).
A nutrient-wide association study is a broad statistical approach. Instead of testing a single nutrient at a time for associations with increased blood pressure, it evaluates multiple nutritional factors. The associations which emerge from one set of data are then validated across a different set of data.
Two large existing studies, “INTERMAP”(4) and “NHANES”(5) were used as data banks for this nutrient-wide association study. “INTERMAP” is an international collaborative study on macronutrients and micronutrients and blood pressure. This cross-sectional study of 4680 men and women aged 40-59 years from 17 countries including China, Japan and the United States was reported in 2003. Eighty-two nutrients from foods and supplements were tallied from dietary interviews.
A somewhat similar ongoing observational population study being done by the United States is the National Health and Nutrition Examination Survey or NHANES. Their data from 1999-2006 was used by the nutrient-wide study to validate associations found in the INTERMAP study.
The nutrient-wide study not only served to review and confirm the findings of INTERMAP and NHANES, but also to find new associations not previously reported. The nutrient-wide study again found alcohol consumption to be associated with elevations in blood pressure. It also again identified increased sodium to potassium intake ratios as pertinent to blood pressure increases. As previously reported (4, 5), dietary phosphorus, magnesium, and iron (non-heme iron) were inversely associated with blood pressure increases. (An inverse association means that those with higher intakes were more likely to be found with lower blood pressures.) The new findings not before noted by the prior studies centered on B vitamins. Thiamine (vitamin B1), folacin (folate,vitamin B-9) and riboflavin (vitamin B12) intakes were inversely associated with blood pressure.
The identification of an association is not the same as the identification of a cause, but the identification of associations does help direct future research. Further evaluations by clinical trials are required to determine if B vitamins might help prevent cardiovascular disease due to high blood pressure (1).
Source: Tzoulaki, Ioanna, et al. “A nutrient-wide association study on blood pressure.” Circulation (2012): CIRCULATIONAHA-112.
Copyright © 2012 American Heart Association, Inc. All rights reserved.
References:
- Tzoulaki, Ioanna , et al. A Nutrient-Wide Association Study on Blood Pressure, Circulation. 2012;126:2456-2464; originally published online October 23, 2012; doi: 10.1161/CIRCULATIONAHA.112.114058 Circulation is published by the American Heart Association.
- Hajjar I, Kotchen JM, Kotchen TA. Hypertension: trends in prevalence, incidence, and control. Annu Rev Public Health. 2006;27:465-9.
- Sacks, Frank MD et al. Effects on Blood Pressure of Reduced Dietary Sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet. N Engl J Med 2001; 344:3-10. DOI: 10.1056/NEJM200101043440101.
- Stamler J, Elliott P, Dennis B, Dyer AR, Kesteloot H, Liu K, Ueshima H, Zhou BF; INTERMAP Research Group. INTERMAP: background, aims, design, methods, and descriptive statistics (nondietary). J Hum Hypertens. 2003;17:591– 608.
- Centers for Disease Control and Prevention (CDC). National Health and Nutrition Examination Survey. http://www cdc gov/nchs/nhanes/ 2011; Accessed 03/06/2012.
