每天两把坚果比每天一把坚果更能降低血液中的胆固醇和甘油三酯，越来越多的研究表明吃坚果可以降低胆固醇。对于大多数人来说，每天吃两把坚果的效果比吃一把更好。

研究用的是树生坚果，例如核桃、杏仁、开心果、澳洲坚果、榛子、花生。尽管花生实际上属于豆科植物，但花生被认为含有同核桃、杏仁及其他树生坚果一样丰富的营养成分。

研究人员发现，对于普通人来说，两把树生坚果比一把更能降低血液中的胆固醇和甘油三酯。

已经有25个研究调查过吃坚果对健康的影响。研究人员在查阅了这25个研究结果后发现，吃坚果使被测试者的血脂水平有相当于一剂量的降低。

{zx1}研究的主导者，加利福尼亚州洛玛连达大学营养系的教授和主席，琼·萨贝德说，“研究确定坚果实际上能降低血液中的胆固醇。”萨贝德博士，是{dy}位在几年前就把吃坚果与降低心脏病风险联系起来的人。

这些研究使得食品和xx管理局在2003年允许生产商在标签上写道：“每天吃43毫升的坚果。。。。。。作为低脂肪及低胆固醇的饮食的一部分可以降低患心脏病的风险。”

萨贝德博士说，研究表明对于普通人来说，数量稍多的坚果-大约67克，或者两把-在降低胆固醇和甘油三酯方面比一把坚果更好。

然而，他说，“我们并不需要太多的量。”一把杏仁大约是8个，一把像花生这样小小的坚果就是15-20个。

萨贝德博士的分析有将近600名高胆固醇或者正常胆固醇的参与者。当中没有任何一位参与者在吃降低胆固醇的xx。

这个分析是三组吃不同数量坚果的人群的对比。

一组是每天吃67克坚果。这组人血液中胆固醇总浓度有平均5.1%的下降，低密度脂蛋白或是LDL或是“有害的”胆固醇也下降了7.4%。

每天吃43克坚果的那组人，总胆固醇浓度下降了3.2%，“有害的”胆固醇下降了4.9%-一剂左右的下降量。

每天吃28克坚果的第三组人，总胆固醇浓度下降了2.8%，“有害的”胆固醇下降了4.2%。

然而，过度肥胖的人没有出现胆固醇的下降-这是个新发现

需要更多的研究来说明为什么坚果对于过度肥胖的人在降低血液胆固醇浓度方面效果并不明显，研究人员说道。

萨贝德博士说，血脂水平降低最明显的人群是有较高的胆固醇的人群，以及高脂肪肉类、乳制品、细粮为主的“西式”饮食人群。相比之下，“地中海式”饮食着重粗粮、水果、蔬菜、鱼以及相对较少的红肉。

研究人员写到：“坚果对“西式”饮食的人群能明显降低血脂水平，而对于较健康的“地中海式”饮食或低脂肪的饮食的人群则效果并不明显。”

25个研究中，约三分之二的研究是用杏仁或者核桃。剩下的三分之一是澳洲坚果、开心果、榛子或者花生。这些研究没有包括松仁或者巴西坚果。

这个研究由加利福尼亚洛玛连达大学以及国际树生坚果营养研究与教育基金会赞助。国际树生坚果营养研究与教育基金会是一个代表树生坚果行业的国际性组织。

More research backing up the cholesterol-lowering benefits of eating nuts indicates that for most people, consuming two handfuls of nuts a day appears to work better than one.

The findings apply to tree nuts such as walnuts, almonds, pistachios, macadamias, hazelnuts and peanuts. Although peanuts actually belong to the legume family, they are considered to have many of the same nutritional components as walnuts, almonds and other tree nuts.

Researchers found that, for the average person, about two servings of tree nuts did a better job of reducing blood cholesterol and triglycerides than one serving.

Researchers who examined the results of 25 previous studies on the health effects of nut consumption found a dose-related improvement in participants' blood-lipid levels.

The lead author of the latest research, Joan Sabaté, says the study "confirms that nuts, indeed, lower cholesterol." A professor and the chairman of the department of nutrition at Loma Linda University, in Loma Linda, Calif., Dr. Sabaté was among the group of researchers that first linked nut consumption to a lower risk of heart attack several years ago.

That finding and others led the Food and Drug Administration in 2003 to allow processors to state on labels that "eating 1.5 ounces per day of most nuts ... as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease."

Dr. Sabaté said the research indicated that for the average person, a slightly higher amount of nuts—about 2.4 ounces, or two servings—does a better job than one serving of lowering cholesterol and triglycerides, another type of fat in the blood.

Still, he said, "we do not need many to get the benefit." One serving of almonds is about eight nuts; a serving of smaller nuts such as peanuts is about 15 to 20 nuts.

Dr. Sabaté's analysis involved nearly 600 people with high or normal blood cholesterol levels. None of the study participants were taking cholesterol-lowering medications.

The analysis compared a control group with two groups assigned to consume two different quantities of nuts.

People in one of the nut groups consumed an average of 67 grams of nuts, or about 2.4 ounces, per day. These people had an average reduction in total blood cholesterol concentration of 5.1%, and a reduction in low-density lipoprotein, or so-called LDL or "bad" cholesterol, of 7.4%.

For the people who consumed about 1.5 ounces of nuts, total cholesterol fell by 3.2%, while "bad" cholesterol fell by 4.9%—suggesting a dose-related response.

Those who consumed about one ounce daily of nuts, total cholesterol fell by 2.8% while LDL cholesterol fell by 4.2%.

Significantly, however, the drops in cholesterol weren't seen in people considered obese—a new finding.

More studies are needed to understand why nuts are less effective at lowering blood cholesterol concentration among obese people, the researchers said.

Dr. Sabaté said the biggest improvement in blood lipid levels were seen among people who started out with higher cholesterol levels, as well as among those who consumed a "Western" diet of high-fat meats, dairy products and refined grains, compared with people consuming a "Mediterranean" diet emphasizing whole grains, lots of fruits and vegetables, fish and relatively little red meat.

"For the general population consuming a Western diet, the incorporation of nuts into their daily diet will result in greater improvement of blood lipid levels than for individuals already following a healthy Mediterranean or low-fat diet," researchers wrote.

Of the 25 studies, about two-thirds of them involved almonds or walnuts. The other one-third of studies looked at either macadamia, pistachio, hazelnuts or peanuts. The studies didn't include pine nuts or Brazil nuts.

The study was funded by Loma Linda University in California and by the International Tree Nut Council Nutrition Research and Education Foundation, an international group that represents the tree nut industry.