Mashed potatoes. Four or more servings a week of
baked, boiled, or mashed potatoes was associated with an increased risk of
hypertension compared with less than one serving a month in women, but not in
men.
Higher intakes of boiled, baked, or mashed potatoes,
and French fries is associated with an increased risk of developing high blood
pressure (hypertension) in adult women and men, according to a study published
by The BMJ today.
The US-based researchers suggest that replacing one
serving a day of boiled, baked, or mashed potatoes with one serving of a
non-starchy vegetable is associated with a lower risk of developing
hypertension.
But a linked editorial argues that studying overall
dietary patterns and risk of disease is more useful than a focus on individual
foods or nutrients.
Potatoes are one of the world's most commonly
consumed foods -- and have recently been included as vegetables in US
government healthy meals programs, due to their high potassium content. But the
association of potato intake with hypertension has not been studied.
So researchers based at Brigham and Women's Hospital
and Harvard Medical School set out to determine whether higher long term intake
of baked, boiled, or mashed potatoes, French fries, and potato chips (crisps)
was associated with incident hypertension.
They followed over 187,000 men and women from three
large US studies for more than 20 years. Dietary intake, including frequency of
potato consumption, was assessed using a questionnaire. Hypertension was
reported by participants based on diagnosis by a health professional.
After taking account of several other risk factors
for hypertension, the researchers found that four or more servings a week of
baked, boiled, or mashed potatoes was associated with an increased risk of
hypertension compared with less than one serving a month in women, but not in
men.
Higher consumption of French fries was also
associated with an increased risk of hypertension in both women and men. However,
consumption of potato chips (crisps) was associated with no increased risk.
After further analyses, the researchers suggest that
replacing one serving a day of boiled, baked, or mashed potatoes with one
serving of a non-starchy vegetable is associated with a decreased risk of
hypertension.
The authors point out that potatoes have a high
glycaemic index compared with other vegetables, so can trigger a sharp rise in
blood sugar levels, and this could be one explanation for the findings.
They also acknowledge some study limitations and say
that, as with any observational study, no firm conclusions can be drawn about
cause and effect.
Nevertheless, they say their findings "have
potentially important public health ramifications, as they do not support a
potential benefit from the inclusion of potatoes as vegetables in government
food programs but instead support a harmful effect that is consistent with
adverse effects of high carbohydrate intakes seen in controlled feeding
studies."
In a linked editorial, researchers at the University
of New South Wales argue that, although diet has an important part to play in
prevention and early management of hypertension, dietary behaviour and patterns
of consumption are complex and difficult to measure.
"We will continue to rely on prospective cohort
studies, but those that examine associations between various dietary patterns
and risk of disease provide more useful insights for both policy makers and
practitioners than does a focus on individual foods or nutrients," they
conclude.
Story Source:
The above post is reprinted from materials provided
by BMJ. Note: Materials may be edited for content and length.
