Folate cuts hypertension

[Guest guest]

Hi All,

It seems that the folate or folic acid level of

our diets as foods and supplements predicts

whether women will develop high blood

pressure. Being younger was important,

but even those with low folate from foods

had the same about half the level high

blood pressure after eight years for the

younger women.

Relative body mass indexes (BMIs) were important.

Those with </= BMI of 25 had greater benefits from folate than

did those women whose BMI was greater than 25.

Values at the greatest versus least levels of total

folate were 0.38 versus 0.7 for younger women,

who were less than 35 versus over 41 years old,

respectively.

Note, that:

" Assessment of Hypertension

The baseline and follow-up biennial

questionnaires asked participants to re-port

whether a clinician had made a new

diagnosis of hypertension during the pre-ceding

2 years, and were also asked

whether they had undergone a physical

examination or screening examination.

Self-reported hypertension was shown to

be highly reliable in the NHS I cohort.

In a subset of women who reported hy-pertension,

medical record review con-firmed

a documented systolic and dia-stolic

blood pressure higher than 140 and

90 mm Hg, respectively, in 100% and

higher than 160 mm Hg and 95 mm Hg

in 77%; additionally, self-reported hy-pertension

was predictive of subse-quent

cardiovascular events.25 A partici-pant

was considered to have prevalent

hypertension if she reported this diag-nosis

on any questionnaire up to and

including the 1991 (NHS II) or 1990 (NHSI)

questionnaires. Women with preva-lent

hypertension were excluded. Cases

included individuals who first reported

hypertension on subsequent question-naires

and whose year of diagnosis was

after the return of the 1991 or 1990 ques-tionnaires. "

Also note, that:

" Folate intake, as well as other dietary

variables, was adjusted for total energy intake. "

The study being a prospective study lends

credence to the results, I believe.

This Week in JAMA

JAMA. 2005;293:269.

Folate Intake and Hypertension

Folic acid supplementation reportedly reduces systolic and

diastolic blood pressure, but whether folate intake modifies the risk

of incident hypertension is not known. Using food frequency data from

women enrolled in 2 prospective cohort studies, Forman and colleagues

examined the risk of incident hypertension in relation to dietary

folate and folic acid supplement intake. During 8 years of follow-up,

the risk of incident hypertension was significantly decreased in

women who consumed at least 1000 µg/d of total folate.

(SEE ARTICLE)

Folate Intake and the Risk of Incident Hypertension Among US Women

P. Forman, MD; B. Rimm, ScD; Meir J. Stampfer, MD, DrPH;

C. Curhan, MD, ScD

JAMA. 2005;293:320-329.

ABSTRACT

... Two prospective cohort studies of 93 803 younger women aged 27

to 44 years in the Nurses' Health Study II (1991-1999) and 62 260

older women aged 43 to 70 years in the Nurses' Health Study I (1990-

1998), who did not have a history of hypertension. Baseline

information on dietary folate and supplemental folic acid intake was

derived from semiquantitative food frequency questionnaires and was

updated every 4 years.

... during 8 years of follow-up.

Results We identified 7373 incident cases of hypertension in

younger women and 12 347 cases in older women. After adjusting for

multiple potential confounders, younger women who consumed at least

1000 µg/d of total folate (dietary plus supplemental) had a decreased

risk of hypertension (relative risk [RR], 0.54; 95% confidence

interval [CI], 0.45-0.66; P for trend <.001) compared with those who

consumed less than 200 µg/d. Younger women's absolute risk reduction

(ARR) was approximately 8 cases per 1000 person-years (6.7 vs 14.8

cases). The multivariable RR for the same comparison in older women

was 0.82 (95% CI, 0.69-0.97; P for trend = .05). Older women's ARR

was approximately 6 cases per 1000 person-years (34.7 vs 40.4 cases).

When the analysis was restricted to women with low dietary folate

intake (<200 µg/d), the multivariable RR for younger women with total

folate intake at least 800 µg/d compared with less than 200 µg/d was

0.55 (95% CI, 0.32-0.94; P for trend = .03), and 0.61 (95% CI, 0.34-

1.11; P for trend = .05) in the older cohort. Among women who did not

take folic acid–containing supplements, dietary folate intake of 400

µg/d or more was not significantly associated with risk of

hypertension.

Conclusion Higher total folate intake was associated with a

decreased risk of incident hypertension, particularly in younger

women.

Cheers, Al Pater