Pity the potato. It's widely
blamed for the fattening of America. But a small new study found that daily consumption of a certain
type of potato -- purple ones, that is --- can help lower blood
pressure, without causing weight gain.
The research, conducted by Joe Vinson, a chemistry professor at the
University of Scranton in Pennsylvania, tracked 18 overweight or obese,
hypertensive subjects who either ate six to eight small purple potatoes,
with skins, at both lunch and dinner
(for a daily total of 218 calories), or had no potatoes as part of
their "normal" diet for four weeks. Then the participants crossed over
to the other regimen.
On average, diastolic blood pressure -- the bottom number in a blood
pressure reading -- dropped by a statistically significant 4.3 percent
and systolic blood pressure -- the top number in a blood pressure
reading -- dropped by 3.5 percent.
While eating potatoes, most of the subjects -- even those on
anti-hypertensive medications -- experienced lower blood pressure, and
none of the subjects gained weight.
Although less popular than their white counterparts, purple potatoes —
increasingly available at supermarkets, specialty food stores and
farmers' markets — boast higher levels of polyphenol antioxidants that
protect body cells against free radical damage that can increase disease
risk. To preserve these powerful plant chemicals, subjects in Vinson’s
study were asked to microwave their potatoes instead of using other
cooking methods.
While research from larger sample sizes is needed, Vinson says the
findings "provide at least some evidence that eating potatoes might be
preventative like drinking coffee to reduce blood pressure." He notes
that, like coffee, potatoes are high in a specific polyphenol called
chlorogenic acid that has been shown to lower blood pressure in mice.
The study, not yet published, was presented this week at the American Chemical Society National Meeting in Denver.
The new research may help redeem the potato's nutritional rep. While a
recent Harvard study
found that having an extra daily serving of potatoes caused a
small but significant weight gain (1 to 2 pounds) over a four year
period, a closer look at the data reveals that weight gain from French
fries was 6 times higher (3.35 pounds) than from boiled, baked, or
mashed potatoes (0.6 pounds).
"The high cooking temperatures used to make French fries and potato
chips seem to destroy most of the healthy substances in potatoes and
leave mainly starch, fat and minerals," according to Vinson. Although
the new study didn't include unfried red- and white-skinned potatoes,
Vinson believes they will prove to produce similar body weight and blood
pressure effects in future, larger human studies.
Indeed, potatoes can be a healthful addition to any diet, even if
you’re trying to lose weight. They’re naturally low in calories, fat,
cholesterol, and sodium, and rich in vitamins and minerals including
vitamin C, an antioxidant that protects against cellular damage and
potassium, a mineral that helps balance body fluids and negate possible
blood pressure-raising effects of a high sodium diet. Potatoes also pack
in fiber that may promote fullness and aid weight management.
To maximize possible nutritional and health benefits and minimize
calories, lightly sauté, mash, or microwave potatoes instead of frying
them and watch how you dress them. My favorite potatoes are red
oven-roasted potatoes, cut in quarters, drizzled with extra virgin olive
oil, some balsamic vinegar, and a pinch each of garlic and onion
powder. Sweet potatoes cut into French fries and baked with a pinch of
paprika and sea salt are also smart options.
Some recommendations for preparing potatoes from Jackie Newgent, R.D., author of "Big Green Cookbook:"
- Hash browns: Combine diced or sliced unpeeled potatoes with shallots
and some chili pepper in a little olive oil. Cover first to steam, and
then remove the lid, add garlic and scallions, and sauté until done.
Finish with a handful of fresh herbs including parsley and rosemary.
- Mashed potatoes: Keep potato skins on to maximize nutrients and add
home-style appeal. For creamy moistness, use almond milk. Also add
roasted garlic for extra flavor (and potential heart-heath benefits).
- Baked or microwaved potatoes: Top with one pat of butter, a large
dollop of plain Greek yogurt, and a generous amount of fresh chives or
scallions. Or add zing with a dollop of tzatziki dip (a Greek dip made
with yogurt, chopped cucumber, and mint).
- Potato salad: For 2 pounds potatoes, use 4 tablespoons mayonnaise, 3
tablespoons stone-ground or Dijon mustard, 2 tablespoons plain Greek
yogurt, and 1 tablespoon white wine vinegar. Serves 6.
Elisa Zied, R.D. is the founder/president of Zied Health
Communications, LLC, author of "Nutrition at Your Fingertips" and
co-author of "Feed Your Family Right.”
For more information, visit elisazied.com
* * Peru - where Potatoes Originated * *
Purple Potatoes Lower Blood Pressure
Minus the Fatty Fixings, Antioxidants in Potatoes May Lower Blood Pressure
Aug. 31, 2011 -- A daily dose of purple potatoes served plain may help your heart. That is, if you steer clear of the deep fryer and fatty toppings.
A new study shows that people who ate plain purple potatoes
cooked in the microwave twice a day for a month lowered their blood
pressure by 3%-4% without gaining weight.
Researchers say the blood
pressure-lowering effects are likely due to the high concentration of
antioxidants found naturally in potatoes. Antioxidants protect your body
from molecules called “free radicals” that can damage healthy cells.
But the frying process destroys the healthy substances in potatoes.
"Mention 'potato' and people think 'fattening, high carbs, empty
calories.' In reality, when prepared without frying and served without
butter, margarine, or sour cream, one potato has only 110 calories and
dozens of healthful phytochemicals and vitamins,” researcher Joe Vinson,
PhD, of the University of Scranton, in Pennsylvania, says in a news
release. “We hope our research helps to remake the potato's popular
nutritional image."
Researchers say potatoes contain a variety of potentially
beneficial phytochemicals at similar levels as broccoli, spinach, and
Brussels sprouts.
Potatoes’ Surprising Effect
In the study, 18 overweight and obese people with high blood pressure
either ate six to eight small purple potatoes (about the size of a golf
ball) with the skins twice daily or no potatoes, as a part of their
normal diet for four weeks.
The results showed that people who ate purple potatoes lowered
their diastolic (the bottom number in a blood pressure reading) blood
pressure by an average of 4.3% and systolic (the top number) by 3.5%.
Researchers say that blood pressure-lowering effect is nearly the same as with oatmeal.
Although the study used purple potatoes, which can increasingly
be found in farmers markets, researchers say red and white potatoes may
have similar effects.
They say the results are especially noteworthy because 14 of the 18 people in the study were already taking drugs
to control their high blood pressure, yet still experienced a further
lowering of their blood pressure. No other changes in body weight or cholesterol were found as a result of adding potatoes to the peoples’ diet.
Researchers say the potato is the most eaten vegetable in the U.S., but it’s gotten a bad rap.
"The potato, more than perhaps any other vegetable, has an
undeserved bad reputation that has led many health-conscious people to
ban them from their diet," Vinson says.
The results of the study were presented this week at the national meeting of the American Chemical Society in Denver.