“Potatoes, Yams, and Sweet Potatoes: Good, Bad, or…?”

“Potatoes, Yams, and Sweet Potatoes:
Good, Bad, or…?”
By Dr. Carolyn McGaughey, N.D.
Fall is upon us, which means root vegetable season is also soon to be here…
…and what a soul-comforting feeling it is to fill our families’ bellies on a cool fall or winter night with oven-roasted yams, parsnips, potatoes, sweet potatoes, and more.
Unfortunately, living in the age we do, scientific scrutiny of foods seems to be the topic du jour, and our friends, the root vegetables, have not been exempt from such scrutiny.  They have, in fact, been labeled as a “bad” food in some circles.  One of my patients recently wrote me an email inquiring about the “bad for you” nature of her beloved potatoes and yams thanks to the suggestion of a friend.  It can, of course, be quite dismaying to find out that a whole food that you may have considered a staple in your diet has suddenly been demonized!
Here is my response to such accusations:
First of all, there are no "bad" foods.

There are foods, however, that are better in moderation; and, health-wise, some people do feel better eliminating certain foods permanently or semi-permanently.
One major example of this is in the case of patients with celiac disease, who literally become sick from eating gluten.

Other people have sensitivities to certain foods.  They may experience vague, non-specific symptoms such as fatigue, gas and bloating, muscle and joint aches, and other symptoms from eating these foods.

The most common food sensitivities are to foods that are genetically modified, over-processed, and non-organic.  The foods that top this list include wheat, corn, soy, dairy, and sugar; as well as non-organic apples, grapes, strawberries, celery, peaches, and spinach (among others).

The general rule of thumb from a health-minded perspective is to eat organic whole foods, since (by definition) they are not genetically modified and they have a lower level of pesticide residue. Organically-grown foods may also contain a greater level of nutrients than conventionally-grown foods, as soils that contain fewer pesticide residues typically have greater bio-diversity:  they contain more beneficial soil organisms that can promote higher nutrient uptake by the plants.
Now that we’ve cleared that up, let’s talk about the "Good or Bad" of potatoes and sweet potatoes (or yams) specifically. This debate stems from several factors, including the fact that root vegetables tend to be higher in starch than other vegetables, and are, therefore, more easily converted to simple sugars in the body.  This can be problematic for those people with blood sugar issues, such as diabetics.  
They also tend to have a high level of pesticide residue if they are conventionally grown: the top of the plant is literally killed with chemicals before the root tuber is harvested.  
Additionally, potatoes belong to the Solanaceae or "Night Shade" family, which has been shown to promote inflammation in the body in some people due to the presence of a group of chemicals called alkaloids. Sweet potatoes, on the other hand, belong to the Convolvulaceae family and yams belong to the Dioscorea family, both of which do not contain the same type of inflammation-promoting alkaloids as potatoes (at least in the edible members of these families).

The "good" of sweet potatoes is that they are an excellent sources of beta-carotene (pre- Vitamin A), Potassium, Magnesium, Pantothenic acid (vitamin B5), and Choline.  Yams are also very high in Vitamin C, Vitamin B6, Folate, and Potassium. These are nutrients that are known for their anti-inflammatory, nervous system, and immune system modulating properties.  Potatoes, on the other hand, are much lower in these nutrients than sweet potatoes and yams; though they still contain many very important trace and macro- minerals, including magnesium and potassium.
So, as you can see, our friends the Mighty Potato, Sweet Potato, and Yam are not all “Bad,” but the “Good” does depend on how they are grown and which ones you choose:  
Choose to eat only sweet potatoes, yams, and potatoes that are organically-grown.  Always eat them with fresh, organic green leafy vegetables, organic fats and oils, and organic herbs that can really boost their nutrient content:
Rosemary (along with other Mediterranean herbs) happens to be an extremely potent anti-inflammatory herb that supports kidney and liver function, and pairs perfectly with potatoes and other root vegetables!
As an aside, every year, the Environmental Working Group (http://www.ewg.org) puts out two lists called "The Dirty Dozen" and "The Clean Fifteen," which ranks conventionally-grown foods based upon the level of pesticides they contain.  Potatoes happen to be "Dirty Dozen" members, while sweet potatoes are members of the "Clean Fifteen" group. Yams didn’t even make the list. Certainly "Food for Thought"!
Yuan, J. Y. Ruan, B. Wang, et al. “Plant Growth-Promoting Rhizobacteria Strain Bacillus amyloliquefaciens NJN-6- Enriched Bio-Organic Fertilizer Suppressed Fusarium Wilt and Promoted the Growth of Banana Plants,” J Agric Food Chem. 2013 April 10.
Wikipedia: Solanacea family, Convolvulaceae family, and Dioscorea family.