The pros and cons of munching on raw potatoes | UTSanDiego.com
QUESTION:
I grew up on a farm in Minnesota, and I always used to like eating raw
potatoes like apples. I still like them better raw than cooked, with a
little salt on them. My mother always said they were healthier that way.
Was she right?
ANSWER:I grew up on a farm in Minnesota, and I always used to like eating raw
potatoes like apples. I still like them better raw than cooked, with a
little salt on them. My mother always said they were healthier that way.
Was she right?
Although not a common component in the American diet, the eating of
raw potatoes has footing in some family traditions. There are some
considerations and interesting science regarding eating them this way.
The potato plant produces a number of defensive (toxic) substances in
the upper plant (leaves, stems and above-ground fruit), but they are
not in the below-ground tubers, which are the “potatoes” we're familiar
with. However, a potato (tuber) that's been injured, exposed to
sunlight or stored for an extended period of time might begin to sprout
or develop patches of green. The green is chlorophyll, produced by
photosynthesis.
the upper plant (leaves, stems and above-ground fruit), but they are
not in the below-ground tubers, which are the “potatoes” we're familiar
with. However, a potato (tuber) that's been injured, exposed to
sunlight or stored for an extended period of time might begin to sprout
or develop patches of green. The green is chlorophyll, produced by
photosynthesis.
Chlorophyll is not toxic, but if photosynthesis has begun, it means
that toxic alkaloids, such as solanine, will be also present. Green
potatoes and especially potato sprouts, should never be eaten. Cooking
does not deactivate these toxins.
that toxic alkaloids, such as solanine, will be also present. Green
potatoes and especially potato sprouts, should never be eaten. Cooking
does not deactivate these toxins.
The raw potato also contains antinutrients that act as enzyme
(protease) inhibitors. This might be a consideration if you don't eat
well and crunching on raw spuds is a regular part of your diet.
(protease) inhibitors. This might be a consideration if you don't eat
well and crunching on raw spuds is a regular part of your diet.
The August 2006 issue of the Journal of Food Science looked at three
of the enzyme inhibitors found in raw potatoes and how they decreased
during cooking. These substances tend to be in the peel, so you might
consider removing the peel. You'll also lose some of the nutrients, but
it's a reasonable trade.
of the enzyme inhibitors found in raw potatoes and how they decreased
during cooking. These substances tend to be in the peel, so you might
consider removing the peel. You'll also lose some of the nutrients, but
it's a reasonable trade.
Unlike cooked potatoes, some of the starch in raw potatoes is digested
poorly. Called “resistant starch,” it passes through the small
intestine into the large intestine, where it ends up being fermented by
the flora that live there.
poorly. Called “resistant starch,” it passes through the small
intestine into the large intestine, where it ends up being fermented by
the flora that live there.
Similar to what happens when we eat legumes, this can result in
increased fecal bulk, bloating and possibly some undesirable
gastrointestinal effects. All this has a positive side in that the
fermentation of resistant starches increases the production of
butyrate, a fatty acid that is associated with favorable effects on
diseases in the colon.
increased fecal bulk, bloating and possibly some undesirable
gastrointestinal effects. All this has a positive side in that the
fermentation of resistant starches increases the production of
butyrate, a fatty acid that is associated with favorable effects on
diseases in the colon.
A study in the March 2009 issue of Gut reported how resistant starch
had positive effects in colon cancer patients. Another benefit is that
raw potatoes don't increase blood sugar like their cooked counterpart.
had positive effects in colon cancer patients. Another benefit is that
raw potatoes don't increase blood sugar like their cooked counterpart.
Interestingly, a study in the November 2005 issue of the European
Journal of Clinical Nutrition reported that if you chill a cooked
potato, you regain some of this effect. (In that study, they served the
chilled potatoes with a vinegar dressing.)
Journal of Clinical Nutrition reported that if you chill a cooked
potato, you regain some of this effect. (In that study, they served the
chilled potatoes with a vinegar dressing.)
The bottom line is that if you want to eat raw potatoes, aside from
peeling them, look for fresh, unblemished, unsprouted potatoes with no
hint of green. If you have a choice, opt for potatoes that are grown
organically.
peeling them, look for fresh, unblemished, unsprouted potatoes with no
hint of green. If you have a choice, opt for potatoes that are grown
organically.
There is a complete list of potato nutrients at tinyurl.com/dyerf5.
This list represents the nutrients in the raw potato. Cooked potatoes
have less vitamin C, thiamine and riboflavin. When eating cooked
potatoes, include the skin if you can.
This list represents the nutrients in the raw potato. Cooked potatoes
have less vitamin C, thiamine and riboflavin. When eating cooked
potatoes, include the skin if you can.
Ed Blonz, Ph.D., is a
nutritional scientist based in Northern California. General-interest
questions about nutrition can be mailed to: Ed Blonz, Focus on
Nutrition, P.O. Box 120191, San Diego, CA 92112-0191, or sent via
e-mail to UTFood@blonz.com.
nutritional scientist based in Northern California. General-interest
questions about nutrition can be mailed to: Ed Blonz, Focus on
Nutrition, P.O. Box 120191, San Diego, CA 92112-0191, or sent via
e-mail to UTFood@blonz.com.
