Friday, September 2, 2011

Interesting Links

In a small pilot study, 18 overweight people ate six to eight small purple potatoes twice daily for a month and found their systolic and diastolic blood pressures (the top and bottom numbers on a blood pressure reading) dropped by 3.5 and 4.3 percent, respectively.

The potatoes were microwaved, with no toppings added.  I prefer mine steamed.  I usually eat 3 to 6 potatoes daily. 

I believe that potatoes frequently correlate with increased disease risks in epidemiological studies because people usually eat them fried or topped with fat and liberally salted, and they travel with otherwise poor quality food choices.  Hence, they tend to serve as a marker for poor diet choices that promote fat gain, metabolic syndrome, and diabetes.  The potatoes themselves are not to blame, they just happen to be at the scene of the crime.

This clinical study shows that the potato itself promotes cardiovascular health without weight gain.
 Potatoes have a very high potassium to sodium ratio (about 56:1 when microwaved, no salt added) and I suspect this potassium infusion provided the blood pressure correction.  However it is possible that potatoes contain some other phytochemical that affects blood pressure as well.  Whole foods are greater than the sum of their parts. 

In Costa Rica, "People who ate at least two servings of beans for every serving of white rice tended to be at lower risk for metabolic syndrome. In those who substituted a serving of beans for a serving of white rice the risk of metabolic syndrome was reduced by 35 percent, the researchers report in American Journal of Clinical Nutrition.”

This study suggests that we are metabolically better adapted to cooked dried beans than to white rice.  Legumes have a lower glycemic load, a higher proportion of protein, and a fiber profile more like fresh vegetables and fruits (higher in soluble fiber) than cereal grains.  

I think we have reason to believe that human ancestral diets included some fresh legumes and this use provided the segue into the use of dried legumes as a part of the agricultural evolution.  I think we are better adapted to fresh than dried legumes.  Dried legumes have more resistant starch than fresh legumes, and this feeds gut flora, resulting in bloating when you exceed your personal legume limit. 

Soaking and sprouting start converting the dried legume back into a fresh vegetable.  Among the dried legumes, the smaller varieties (lentils, adukis, mungs) and those in the pea family (peas, chickpeas) have lower proportions of the resistant starch.  

People who trained vigorously for 45 minutes at a level of effort that increased body temperature, raised heart rate, and induced sweating burned an average of 190 extra calories in the 14 hours following the training session.   They also burned about 590 total calories in the exercise session itself. This contrasts with low intensity exercise, which does not increase caloric expenditure in the hours following exercise sessions.  

As this article points out, if you need mental refreshment, a coffee break will probably backfire, but a growing body of research shows that making contact with live plants and animals, even if vicarious (photos of forests) is more effective than other diversions.   A little time enjoying the sights and sounds of nature also has proven successful at relieving depression and anxiety and boosting cognitive performance.

This makes sense from an ancestral perspective.  For millenia the human body-mind adapted to life surrounded by plants and animals in wild settings.  Our nervous systems are adapted to the stimuli provided by living environments.  Now in civilization we spend most of our time in less lively built environments.  Our nervous systems apparently go awry in such spaces.  

I suspect this contributes not only to mental illness, but also to disorders we tend to consider 'physical' like cardiovascular disease.  The great health of isolated tribes might have a lot to do with the fact that the human neuroendocrine system is adapted to their more natural surroundings.  I would guess that they have very different levels of various neuroendocrine chemicals (such as adrenaline and cortisol) found out of balance in diseases like metabolic syndrome.

This also means we can help ourselves by naturalizing our built environments.  The Chinese developed an art of building and arranging environments to make them more natural and conducive to human vitality.  They routinely incorporated natural sights and sounds--like stones, flowing water, fish ponds and tanks, plants and trees-- into built environments with the express intent of maximizing the beneficial impact on human health and awareness.  

This part of Feng Shui (literally translated, Wind Water) centers on understanding how various environmental elements affect the nervous system. Its not hocus-pocus.   It focuses on how to make built environments compatible with human needs by incorporating the 'five elements' of water, wood, fire, soil, and mineral, and balancing complementary such as bright and dark, wet and dry, hard and soft, heavy and light in ways that calm the nervous system or produce another desired effect, depending on location.  

By bringing the elements of wind, water, wood, sunlight or fire, earth, and stone into our home and work spaces, we make them more like our ancestral environment and beneficial to our health.  Then, we simply arrange them in the way than makes the space feel most comfortable and fitting for the use. 


BJ said...

So do you think that added fats to the potatoes are all bad? Disregarding food reward, would adding such things as grass fed butter or bacon fat be bad? I was kind of thinking that you meant vegetable oils and trans fats that they would normally be cooked with in restaurants and fast food joints.

mkedst said...

Hi Don,

The potato study mentions:
"The skin is key ... That's where the nutrients are."

It's also been considered a source of toxins.

What's your view on eating the potato skin?


Sarah Barracuda said...

Hi Don,

So do you have a definitive, traditional Asian diet-informed method of soaking legumes? Soaking in an acidic medium, as some recommend, doesn't square with my knowledge of traditional Asian diets. I would love to reintroduce legumes, but alas, my gut would beg to differ.


Don said...


Quantity, quality, context. I personally put a little olive tapenade, olives, cashew dressing, or less often, olive oil, with some black pepper or Thai garlic chili on them, just enough to give a good flavor.

You're right though, I was mainly referring to trans fats used in commercial.

Don said...


I usually take the skin off. There are plenty of nutrients in the flesh. I find the skin causes excessive gas.

Don said...


Definitive? No.

In Japan, they soak and cook beans with kelp. I find this helps a little.

Also important to skim off all the foam that surfaces when you first bring them to a boil.

Also, traditional legume-rich cuisines usually add plenty of carminative herbs to the pot: bay leaf, cumin, mustard, fennel, chili, etc. These help also.

And they usually eat the beans in small portions ~1/2 cup or so per serving.

But if something gives you discomfort, try reducing the dose or just avoid. Beans have beneficial properties in small doses, and they are better in some respects than grains, but I don't consider them essential.

Aaron Blaisdell said...

I enjoy potatoes on a regular basis. I always peel them first, then steam them or boil and nash them. I kinda figured out the skimming the foam off the surface of the boiling water idea on my own when I assumed they must be the saponins (sp), and thus act like soap.