Busting belly fat may be yet another of blueberries’ health benefits.
A new study shows rats who ate a diet rich in blueberries lost abdominal fat -- the kind of fat linked to heart disease and diabetes -- as well as experienced other health benefits like lowered cholesterol and improved glucose control even if their diet wasn’t otherwise heart-healthy.
"Some measurements were changed by blueberry even if the rats were on a high-fat diet," researcher E. Mitchell Seymour, MS, of the University of Michigan’s Cardioprotection Research Laboratory, says in a news release.
Researchers say the results suggest that antioxidant-rich blueberries may change how the body stores and processes glucose or sugar for energy, thereby reducing the risk of both heart disease and diabetes.
"The benefits of eating fruits and vegetables have been well researched, but our findings in regard to blueberries show the naturally occurring chemicals they contain, such as anthocyanins, show promise in mitigating these health conditions," researcher Steven Bolling, MD, of the University of Michigan, says in the release.
In the study, presented at Experimental Biology 2009, researchers fed rats bred to become obese either a high-fat or low-fat diet enriched with whole blueberry powder or carbohydrates as 2% of their total diet.
After 90 days, the rats fed blueberries had less abdominal fat, lower cholesterol, and improved glucose control and insulin sensitivity. The latter two factors are markers of how well the body processes sugar for energy and are related to diabetes risk.
These health benefits of blueberries were evident in rats fed both high- and low-fat diets enriched with the blueberry powder. But the benefits were greatest among those who ate a low-fat diet.
In addition to the other heart health benefits of blueberries, those fed the low-fat blueberry diet also lost body weight and fat mass compared to those on the high-fat diet.
Although more research is needed to confirm these results in humans, a related study presented at the same conference showed that men with risk factors for heart disease who drank wild blueberry juice for three weeks seemed to experience slight improvements in glucose and insulin control.
消除腹部脂肪可能并不是藍(lán)莓的保健功能,因?yàn)樾卵芯堪l(fā)現(xiàn)的攝入豐富藍(lán)莓后的小鼠減去腹部的脂肪是一類與心臟病和糖尿病有關(guān)的脂肪。即使小鼠自身的飲食對(duì)于心臟并不健康,同時(shí)食用藍(lán)莓也能降低膽固醇和促進(jìn)對(duì)血糖控制。密西根大學(xué)心肌研究實(shí)驗(yàn)室的研究員E.Mitchell Seymour在新聞發(fā)布中提出,即使小鼠攝入高脂肪膳食,藍(lán)莓也能改變一些心臟機(jī)能的測(cè)量結(jié)果。
研究員認(rèn)為其原因很可能是具有強(qiáng)抗氧化性的藍(lán)莓能影響人體中糖類的能量代謝和貯藏,從而減低了患心臟病和糖尿病的危險(xiǎn)。
來(lái)自密西根大學(xué)的研究員Steven Bolling在另一新聞發(fā)布中提到,對(duì)于食用水果和蔬菜對(duì)人體健康帶來(lái)的有利之處已經(jīng)得到了廣泛地深入研究,而我們對(duì)于藍(lán)莓的研究旨在對(duì)其含有的天然化學(xué)成分分析,如藍(lán)莓中的花青素能減輕心臟病和糖尿病等不利于健康的狀況。
2009年發(fā)表在《生物實(shí)驗(yàn)》的研究中,研究人員利用高脂肪和低脂肪的膳食把小鼠培育成肥胖體形,并分成四組,每?jī)山M分別加入質(zhì)量為總攝入量2%的藍(lán)莓粉和碳水化合物。90天以后,喂養(yǎng)了藍(lán)莓的小鼠的腹部脂肪得到減少,膽固醇降低,血糖控制和胰島素敏感性得到提高。
后兩個(gè)結(jié)果均影響體內(nèi)糖類能量的代謝以及與患糖尿病的風(fēng)險(xiǎn)有關(guān)。在都加入了藍(lán)莓粉的高脂肪和低脂肪膳食培育的小鼠身上證明了藍(lán)莓的保健功能。
而且,藍(lán)莓的保健功效在低脂肪膳食的小鼠身上得到最大得體現(xiàn)。除了藍(lán)莓對(duì)心臟健康的功能以外,均攝入了藍(lán)莓粉的低脂肪膳食小鼠與高脂肪膳食小鼠相比,其體重和脂肪的減少更為明顯。
盡管藍(lán)莓的這些保健功效仍需要進(jìn)一步地在人體上進(jìn)行研究才能得以證實(shí),一個(gè)在同一會(huì)議中發(fā)表的相關(guān)研究表示,有患心臟病風(fēng)險(xiǎn)的人在飲用野生藍(lán)莓汁三周后,其血糖和胰島素的控制得到輕微的促進(jìn)。