Dietary Patterns

• Diversity of dietary patterns globally• Nutrition transition• Complementary proteins• Glycemic Index and Glycemic Load• Traditional Native foods and diabetes

Dietary patterns

Proportions of plant and animal foods in traditional diets of human cultures form a continuum from complete vegetarian (vegan) to mostly animal-based– India– Maasai, Inuit (“Eskimo”)

Nutrition TransitionChanges in lifestyle and urbanization can lead to changes in diet.

These changes are not always for the better.

Social status vs. nutrition– noodles and white rice in Andes– Sago, manioc, sweet potato

Urbanization and socioeconomic change– simplification of diet to a limited # of high-energy foods– increased diabetes, hypertension, cancer– decreased legumes, increased oils (fried street food)– in Kenya calories from oils 8% in 1963 to 20% in 1998– official national and international policies ignore wild and cultivated

biodiversity in developing regions– focus on single nutrient (Vitamin A) at the expense of other nutrients or

functional factors in a diverse diet

Timothy Johns (2003) African Journal Of Food, Agriculture, Nutrition And Development (AJFAND) 3(1):45-52http://www.ajfand.net/IssueIV%20files/IssueIV-Peer%20Reviewed%20Article%20-%20Johns.htm

Complementary proteins• Nine “essential” amino acids are needed in correct

proportion in human diet• Legumes are high in protein overall (thanks to nitrogen-

fixing Rhizobia in root nodules)– have adequate lysine and tryptophan– but low in sulfur-containing amino-acids (methionine & cysteine)– soybeans are unusual in having “complete” protein – similar to

animal proteins (meat, eggs, milk) in having good proportion of all 9 “essential amino acids”

• Grains (cereals) are lower in protein overall – adequate in methionine & cysteine– low in lysine

• Many cultures in the world have complementary grain/legume combination as primary staple: – maize & pinto beans, rice & soy, rice & black beans

Complementary proteins“Essential” amino acids:• valine• leucine• isoleucine• the sulfur-containing amino acids:

methionine and cysteine• the aromatic amino acids:

phenylalanine and tyrosine• tryptophan• threonine• lysine

Glycemic Index• GI measures the increase in blood

glucose in the 2 hours after consuming a food, per gram of carbohydrate.– Higher peak and higher overall blood glucose

response– two versions: 100 = glucose or white bread– depends on kinds of starch (amylose vs.

amylopectin)– other aspects or contents that slow digestion

or slow food from leaving stomach (oils, undercooking, fiber content, vinegar, trapping starches within pectins, etc.)

The effect on blood glucose from a high versus low glycemic index carbohydrate

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Glycemic Index• GI measures the increase in blood

glucose in the 2 hours after consuming a food, per gram of carbohydrate.– Higher peak and higher overall blood glucose

response– two versions: 100 = glucose or white bread– depends on kinds of starch (amylose vs.

amylopectin)– other aspects or contents that slow digestion

or slow food from leaving stomach (oils, undercooking, fiber content, trapping starches within pectins, etc.)

Starch: amylose vs amylopectin

http://www.majordifferences.com/2013/02/difference-between-amylose-and_17.html

Glycemic Index examples

• Low GI 55 or less – most fruit and vegetables (except potatoes),

wholegrains, basmati rice, long grain rice, pasta

• Medium GI 56 - 69 – sucrose, candy bar, croissant, some brown

rices • High GI 70

– corn flakes, baked potato, some white rices (e.g., jasmine), white bread

Glycemic Load

• GL = GI × carbohydrate content– example: banana vs. tortilla both GI = 52,– but 20% carbs vs. 48% carbs,– so GL of 10 vs. 25

• Long-term diet with high GL has high risks:– type 2 diabetes– cardiovascular disease, atherosclerosis– colon cancer, breast cancer, obesity

Traditional native foods and diabetes

• “As recently as the early 1960s, diabetes was unknown among the Tohono O'odham. Today, more than 50 percent of the population develops the disease, the highest rate in the world. As a degenerative disease, diabetes causes many subsequent health problems, including kidney failure, loss of eyesight, circulatory problems and severe organ damage.”

• “In… ‘The Desert Smells Like Rain,’ Gary Paul Nabhan notes that the O’odham still used traditional dry land methods to cultivate more than 10,000 acres as late as the 1920s. By 1949, that acreage had declined to 2,500 acres. Today that number is certainly less than 100 acres, perhaps not more than ten.”

– Quoted from:– http://www.oxfamamerica.org/whatwedo/where_we_work/united_states/news_publications/art4144.html

(accessed 2008, no longer at that URL)

Traditional native foods and diabetes

• “Traditional O'odham foods--such as tepary beans, mesquite beans, cholla (cactus) buds and chia seeds--help regulate blood sugar and significantly reduce both the incidence and effects of diabetes.”

http://www.desertharvesters.greenbicycle.net/images/mesquitebeans.jpghttp://image32.webshots.com/33/4/54/13/2136454130094247191Mzvpsy_fs.jpg

Traditional native foods and diabetes

• “Traditional O'odham foods--such as tepary beans, mesquite beans, cholla (cactus) buds and chia seeds--help regulate blood sugar and significantly reduce both the incidence and effects of diabetes.”

• “Diabetes Project Coordinator Felipe Molina, who is himself a member of the Yaqui nation, says that they focus on promoting five slow release foods. Slowly digested and absorbed, these are foods that are low on the glycemic index. These foods are beans—particularly tepary beans—chia seeds, prickly pear pad or nopalitos, mesquite flour, and acorns.” – Quoted from:– http://www.mendosa.com/seeds.htm

Traditional native foods and diabetes

• “Two primary attributes of traditional Tohono O’odham foods are thought to contribute to reductions in both the incidence and severity of diabetes.

• First, the soluble fiber, tannins and inulin in one group of traditional foods (which includes mesquite bean pods, acorns and tepary beans) helps reduce blood sugar levels, slow sugar absorption rates, and improve insulin production and sensitivity. Indeed, these foods are known to be among the 10 percent most effective foods at controlling blood-sugar levels.

• Second, a complimentary group of traditional foods (including prickly pear fruits and pads, cholla cactus buds, chia seeds and mesquite bean pods) contain mucilaginous polysaccharides gums that slow the digestion and absorption of sugary foods.” – COMMUNITY ATTITUDES TOWARD TRADITIONAL TOHONO

O’ODHAM FOODS by TOHONO O’ODHAM COMMUNITY ACTION AND TOHONO O’ODHAM COMMUNITY COLLEGE

http://www.tocaonline.org/Programs/Food%20System/images/usdareport.pdf

Tepary bean Phaseolus acutifolius

• Family: Fabaceae• More drought tolerant

than common bean (Phaseolus vulgaris)

• Native to southwest USA and Mexico

• antidiabetic• role in traditional

O’odham foods (in this lecture and in readings)

http://www.kcrw.com/etc/programs/gf/gf071215cities_of_spice_best/tepary-beans.jpghttp://www.eastvalleytribune.com/images/photos/2008/03/14/ckq7hx8k.jpg