Recent Studies

Diets that contain buckwheat have been linked to lowered risk ofdeveloping high cholesterol and high blood pressure. The Yi people ofChina consume a diet high in buckwheat (100 grams per day, about3.5 ounces). When researchers tested blood lipids of 805 Yi Chinese,they found that buckwheat intake was associated with lower totalserum cholesterol, lower low-density lipoprotein cholesterol (LDL,the form linked to cardiovascular disease), and a high ratio of HDL(health-promoting cholesterol) to total cholesterol.

Buckwheat’s beneficial effects are due in part to its rich supplyof flavonoids, particularly rutin. Flavonoids are phytonutrients thatprotect against disease by extending the action of vitamin C andacting as antioxidants. Buckwheat’s lipid-lowering activity is largelydue to rutin and other flavonoid compounds. These compounds helpmaintain blood flow, keep platelets from clotting excessively (plateletsare compounds in blood that, when triggered, clump together, thuspreventing excessive blood loss, and protect LDL from free radicaloxidation into potentially harmful cholesterol oxides. All theseactions help to protect against heart disease.

Buckwheat is also a good source of magnesium. This mineralrelaxes blood vessels, improving blood flow and nutrient deliverywhile lowering blood pressure—the perfect combination for a healthycardiovascular system.

The nutrients in buckwheat may contribute to blood sugar control. In a test that compared the effect on blood sugar of whole buckwheat groats to bread made from refined wheat flour, buckwheat groatssignificantly lowered blood glucose and insulin responses. Wholebuckwheats also scored highest on their ability to satisfy hunger.

When researchers followed almost 36,000 women in Iowa duringa six-year long study of the effects of whole grains and the incidenceof diabetes, they found that women who consumed an average of 3servings of whole grains daily had a 21 percent lower risk of diabetescompared to those who ate one serving per week. Because buckwheatis a good source of magnesium, it is also important to note thatwomen who ate the most foods high in magnesium had a 24 percentlower risk of diabetes compared to women who ate the least.

Canadian researchers, publishing their findings in the Journalof Agricultural and Food Chemistry have found new evidence thatbuckwheat may be helpful in the management of diabetes. In aplacebo-controlled study, a single dose of buckwheat seed extractlowered blood glucose levels by 12-19% at 90 and 120 minutes afteradministration when fed to laboratory animals with chemicallyinduceddiabetes. No glucose reduction was seen in animals givenplacebo. The component in buckwheat responsible for its bloodglucose-lowering effects appears to be chiro-inositol, a compoundthat has been shown in other animal and human studies to play asignificant role in glucose metabolism and cell signaling. Whileresearchers do not yet know precisely how it works, preliminary evidence suggests chiro-inositol makes cells more sensitive to insulinand may even act as an insulin mimic. Results of the Canadianstudy were so promising that one of the lead investigators, RomanPrzbylski, is currently collaborating with Canadian-based KadeResearch to develop new buckwheat varieties with much higheramounts of chiro-inositol. Although the animals used in this studyhad the equivalent of Type 1 diabetes in humans, the researchers areconfident that buckwheat will exert similar glucose-lowering effectswhen given to animals with Type 2 diabetes, which is the next studyon their agenda. Type 2 or non-insulin dependent diabetes, which isby far the most common form in humans (90% of diabetes in humansis Type 2), is characterized by an inability of cells to respond properlyto insulin Table 1.

Table 1: Buckwheat, Nutritional value per 100 gm.

Buckwheat and other whole grains are also rich sources ofmagnesium, a mineral that acts as a co-factor for more than 300enzymes, including enzymes involved in the body’s use of glucoseand insulin secretion.

The FDA permits foods that contain at least 51% whole grainsby weight (and are also low in fat, saturated fat, and cholesterol) todisplay a health claim stating consumption is linked to lower riskof heart disease and certain cancers. Now, research suggests regularconsumption of whole grains also reduces risk of type 2 diabetes.(Van Dam RM, Hu FB, Diabetes Care).

In this 8-year trial, involving 41,186 participants of the Black Women’s Health Study, research data confirmed inverse associationsbetween magnesium, calcium and major food sources in relationto type 2 diabetes that had already been reported in predominantlywhite populations.

Risk of type 2 diabetes was 31% lower in black women whofrequently ate whole grains compared to those eating the least ofthese magnesium-rich foods. When the women’s dietary intakeof magnesium intake was considered by itself, a beneficial, butlesser—19%—reduction in risk of type 2 diabetes was found,indicating that whole grains offer special benefits in promoting healthyblood sugar control. Daily consumption of low-fat dairy foods wasalso helpful, lowering risk of type 2 diabetes by 13%. Get the benefitsof both buckwheat and dairy by enjoying a hearty breakfast of hotbuckwheat topped with low-fat milk and a spoonful of maple syrup.

Eating foods high in insoluble fiber, such as buckwheat, can helpwomen avoid gallstones, shows a study published in the AmericanJournal of Gastroenterology.

Studying the overall fiber intake and types of fiber consumed over a 16 year period by over 69,000 women in the Nurses Health Study, researchers found that those consuming the most fiber overall (both soluble and insoluble) had a 13% lower risk of developing gallstones compared to women consuming the fewest fiber-rich foods.

Those eating the most foods rich in insoluble fiber gained evenmore protection against gallstones: a 17% lower risk compared towomen eating the least. And the protection was dose-related; a5-gram increase in insoluble fiber intake dropped risk dropped 10%.

How do foods rich in insoluble fiber help prevent gallstones?Researchers think insoluble fiber not only speeds intestinal transittime (how quickly food moves through the intestines), but reducesthe secretion of bile acids (excessive amounts contribute to gallstoneformation), increases insulin sensitivity and lowers triglycerides(blood fats). Abundant in all whole grains, insoluble fiber is alsofound in nuts and the edible skin of fruits and vegetables includingtomatoes, cucumbers, many squash, apples, berries, and pears. Inaddition, beans provide insoluble as well as soluble fiber.

Research reported at the American Institute for Cancer Research(AICR) International Conference on Food, Nutrition and Cancer, byRui Hai Liu, M.D., Ph.D., and his colleagues at Cornell Universityshows that whole grains, such as buckwheat, contain many powerfulphytonutrients whose activity has gone unrecognized becauseresearch methods have overlooked them.

Despite the fact that for years researchers have been measuringthe antioxidant power of a wide array of phytonutrients, they havetypically measured only the “free” forms of these substances, whichdissolve quickly and are immediately absorbed into the bloodstream.They have not looked at the “bound” forms, which are attached to thewalls of plant cells and must be released by intestinal bacteria duringdigestion before they can be absorbed.

Phenolics, powerful antioxidants that work in multiple ways toprevent disease, are one major class of phytonutrients that have beenwidely studied. Included in this broad category are such compoundsas quercetin, curcumin, ellagic acid, catechins, and many others thatappear frequently in the health news.

When Dr. Liu and his colleagues measured the relative amountsof phenolics, and whether they were present in bound or free form,in common fruits and vegetables like apples, red grapes, broccoliand spinach, they found that phenolics in the “free” form averaged76% of the total number of phenolics in these foods. In whole grains,however, “free” phenolics accounted for less than 1% of the total,while the remaining 99% were in “bound” form.

In his presentation, Dr. Liu explained that because researchershave examined whole grains with the same process used to measureantioxidants in vegetables and fruits&mash;looking for their contentof “free” phenolics”—the amount and activity of antioxidants inwhole grains has been vastly underestimated.

Despite the differences in fruits’, vegetables’ and whole grains’content of “free” and “bound” phenolics, the total antioxidant activityin all three types of whole foods is similar, according to Dr. Liu’sresearch. His team measured the antioxidant activity of various foods,assigning each a rating based on a formula (micromoles of vitaminC equivalent per gram). Broccoli and spinach measured 80 and 81,respectively; apple and banana measured 98 and 65; and of the wholegrains tested, corn measured 181, whole wheat 77, oats 75, and brownrice 56.

Dr. Liu’s findings may help explain why studies have shown thatpopulations eating diets high in fiber-rich whole grains consistentlyhave lower risk for colon cancer, yet short-term clinical trials thathave focused on fiber alone in lowering colon cancer risk, often to thepoint of giving subjects isolated fiber supplements, yield inconsistentresults. The explanation is most likely that these studies have nottaken into account the interactive effects of all the nutrients in wholegrains—not just their fiber, but also their many phytonutrients. As faras whole grains are concerned, Dr. Liu believes that the key to theirpowerful cancer-fighting potential is precisely their wholeness. Agrain of whole wheat consists of three parts—its endosperm (starch),bran and germ. When wheat—or any whole grain—is refined, its branand germ are removed. Although these two parts make up only 15-17% of the grain’s weight, they contain 83% of its phenolics. Dr. Liusays his recent findings on the antioxidant content of whole grainsreinforce the message that a variety of foods should be eaten goodhealth. “Different plant foods have different phytochemicals,” hesaid. “These substances go to different organs, tissues and cells, wherethey perform different functions. What your body needs to ward offdisease is this synergistic effect—this teamwork—that is produced byeating a wide variety of plant foods, including whole grains.

One type of phytonutrient especially abundant in whole grainssuch as buckwheat are plant lignans, which are converted by friendlyflora in our intestines into mammalian lignans, including one calledenterolactone that is thought to protect against breast and otherhormone-dependent cancers as well as heart disease. In addition towhole grains, nuts, seeds and berries are rich sources of plant lignans,and vegetables, fruits, and beverages such as coffee, tea and wine alsocontain some. When blood levels of enterolactone were measuredin 857 postmenopausal women in a Danish study published inthe Journal of Nutrition, women eating the most whole grains werefound to have significantly higher blood levels of this protectivelignan. Women who ate more cabbage and leafy vegetables also had higher enterolactone levels.

Eating a serving of whole grains, such as buckwheat, at least 6times each week is an especially good idea for postmenopausalwomen with high cholesterol, high blood pressure or other signs ofcardiovascular disease (CVD).

A 3-year prospective study of over 220 postmenopausal womenwith CVD, published in the American Heart Journal, shows that thoseeating at least 6 servings of whole grains each week experienced both:

• Slowed progression of atherosclerosis, the build-up ofplaque that narrows the vessels through which blood flows, and

• Less progression in stenosis, the narrowing of the diameterof arterial passageways.

The women’s intake of fiber from fruits, vegetables and refinedgrains was not associated with a lessening in CVD progression.

Heart failure is the leading cause of hospitalization among theelderly in the United States. Success of drug treatment is only partial(ACE inhibitors and beta-blockers are typically used; no evidencehas found statins safe or effective for heart failure), and its prognosisremains poor. Follow up of 2445 discharged hospital patients withheart failure revealed that 37.3% died during the first year, and 78.5%died within 5 years.

Since consumption of whole grain products and dietary fiberhas been shown to reduce the risk of high blood pressure and heartattack, Harvard researchers decided to look at the effects of cerealconsumption on heart failure risk and followed 21,376 participants inthe Physicians Health Study over a period of 19.6 years.

After adjusting for confounding factors (age, smoking, alcoholconsumption, vegetable consumption, use of vitamins, exercise, andhistory of heart disease), they found that men who simply enjoyed adaily morning bowl of whole grain (but not refined) cereal had a 29%lower risk of heart failure.

When researchers looked at how much fiber 35,972 participantsin the UK Women’s Cohort Study ate, they found a diet rich in fiberfrom whole grains, such as buckwheat, and fruit offered significantprotection against breast cancer for pre-menopausal women. (CadeJE, Burley VJ, et al., International Journal of Epidemiology).

Pre-menopausal women eating the most fiber (>30 grams daily)more than halved their risk of developing breast cancer, enjoyinga 52% lower risk of breast cancer compared to women whose dietssupplied the least fiber (<20 grams/day).

Fiber supplied by whole grains offered the most protection. Premenopausalwomen eating the most whole grain fiber (at least 13 g/day) had a 41% reduced risk of breast cancer, compared to those withthe lowest whole grain fiber intake (4 g or less per day).

Fiber from fruit was also protective. Pre-menopausal womenwhose diets supplied the most fiber from fruit (at least 6 g/day) had a29% reduced risk of breast cancer, compared to those with the lowestfruit fiber intake (2 g or less per day).

Results of a prospective study involving 51,823 postmenopausalwomen for an average of 8.3 years showed a 34% reduction in breastcancer risk for those consuming the most fruit fiber compared tothose consuming the least. In addition, in the subgroup of womenwho had ever used hormone replacement, those consuming the mostfiber, especially cereal fiber, had a 50% reduction in their risk of breastcancer compared to those consuming the least.[2]

HEALTH BENEFITS

Buckwheat is having lots of beneficial effect on human body,which are as follows:

Buckwheat enhanced gluten-free bread a healthier glutenfreealternative

Buckwheat starch is a good energy source

Buckwheat protein shows promise for lowering blood glucose

Germinated buckwheat extract decreases blood pressure

Buckwheat provides prebiotic-like benefits and can beconsidered a healthy food

Eating buckwheat products produces lower GI response

lowered risk of diabetes

Lignans Protect against Heart Disease

Significant Cardiovascular Benefits for PostmenopausalWomen

Can be Protective against Breast Cancer

Protective against Postmenopausal Breast Cancer

Whole Grains and Fish Highly Protective against ChildhoodAsthma [3]