Beans and rice, the classic food combo in many parts of the
world, canreduce postprandial glycemic elevations in people with type 2
diabetes,according to an American study published in the Nutrition journal.
Diet and lifestyle
changes arevery important interventions to prevent and control type 2 diabetes.
Beans are high in
protein,omega-3 fatty acids and anti-oxidants, and low in fat. They are also
goodsources of iron, folate, magnesium and zinc. Earlier studies found that
beanshave some action similar to the diabetes medication, acarbose.
It is also known that
beans havea low glycemic index (GI) which means they produce a relatively low
rise inblood glucose after a meal. However, white rice has a high GI and can
causepostprandial glycemic elevations, which damage the tissues and other
organs.
So, to find out if
thepostprandial glucose values are lowered by beans and rice combo diet,
Americanresearchers, Sharon Thompson, Donna Winham, and Andrea Hutchins,
compared theglycemic response of beans and rice meals with rice alone in adult
type 2diabetics.
Data from seventeen
men and women, with type 2 diabetescontrolled on metformin or diet / exercise,
between the ages of 35 and 70 yearswas analysed in this study. The researchers
selected pinto beans (GlycemicIndex = 45), black beans (GI = 20) and red kidney
beans (GI = 20) and long grainwhite rice (GI = 80) for their study.
Participants received the four test mealsin random order. Three meals included
pinto beans, black beans or dark redkidney beans along with half a cup of white
long grain rice respectively. Theamount of beans was standardized to provide
50g of carbohydrates while theweight of the white rice was kept constant. The
fourth meal was the controlmeal which included 180g of steamed long grain white
rice. Meals were consumedat breakfast after a 12-hour fast.
Capillary blood
glucose concentrations at baseline and at30 minute intervals up to 180 minutes
following the meal were collected. Theresults of the study were analyzed
statistically.
The results showedthat postprandial glucose concentrations
were significantly lower for all threetraditional bean and rice meals as
compared with the white rice meal.
The findings are in
agreementwith other studies that show intermediate responses with mixed meals
of highand low GI foods.
The results also show
that -
. All three test meals reduced the average
2-hourpostprandial glucose below 140 mg/dl, the International Diabetes
Federationrecommended glycemic control goal.
. Counseling patients to exclude cultural foods like thebean
and rice combination may be unwarranted for persons with type 2
diabetes,especially in the U.S.,
Latin America, and Mediterranean and Middle
Eastcountries.
. The three different beans varieties exhibitedsignificantly
different levels of glycemic response. The pinto and black beanand rice
combinations produced a lower glycemic response overall than the darkred kidney
bean and rice meal.
The authors suggested
that it is important to investigatemultiple bean varieties rather than assuming
all are the same.
'Dietary recommendations,
materialsand counseling should be culturally sensitive and take into account
valuedtraditional foods such as beans, especially when the scientific
evidencesupports their beneficial role in the diet', concluded the researchers.
They further add -
'While promotingtraditional foods is a non-pharmacological way to manage type 2
diabetes,knowing which beans are most effective can help improve dietary
adherence withan appropriate cultural twist'.
Source: Thompson SV, Winham DM, Hutchins AM. Bean and ricemeals reduce postprandial glycemic response in adults with type 2 diabetes: across-over study. Nutr J. 2012 Apr 11;11(1):23.http:www.nutritionj.com/content/pdf/1475-2891-11-23.pdf