Potatoes and Human Health
土豆与人类健康
by Stephan Guyenet PhD
http://wholehealthsource.blogspot.com/2010/09/potatoes-and-human-health-part-i.html?m=1
http://wholehealthsource.blogspot.com/2010/09/potatoes-and-human-health-part-ii.html?m=1
http://wholehealthsource.blogspot.com/2010/10/potatoes-and-human-health-part-iii.html?m=1
Potatoes: an Introduction土豆介绍
Over 10,000 years ago, on the shores of lake Titicaca in what is now Peru, a culture began to cultivate a species of wild potato, Solanum tuberosum. They gradually transformed it into a plant that efficiently produces roundish starchy tubers, in a variety of strains that suited the climactic and gastronomic needs of various populations. These early farmers could not have understood at the time that the plant they were selecting would become the most productive crop in the world*, and eventually feed billions of people around the globe.
10,000多年前,在现在秘鲁的的喀喀湖沿岸,一种文化开始种植一种野生土豆,即马铃薯。他们逐渐将其转化为一种植物,该植物能够有效地生产圆形淀粉块茎,其品种多样,适合不同人群的气候和美食需求。 这些早期的农民当时无法理解,他们选择的植物会成为世界上产量最高的作物*,并最终养活全球数十亿人。
Wild potatoes, which were likely consumed by hunter-gatherers before domestication, are higher in toxic glycoalkaloids. These are defensive compounds that protect against insects, infections and… hungry animals. Early farmers selected varieties that are low in bitter glycoalkaloids, which are the ancestors of most modern potatoes, however they didn't abandon the high-glycoalkaloid varieties. These were hardier and more tolerant of high altitudes, cold temperatures and pests. Cultures living high in the Andes developed a method to take advantage of these hardy but toxic potatoes, as well as their own harsh climate: they invented chuños. These are made by leaving potatoes out in the open, where they are frozen at night, stomped underfoot and dried in the sun for many days. What results is a dried potato with a low glycoalkaloid content that can be stored for a year or more. 野生土豆在驯化前很可能被狩猎采集者食用,其有毒配糖生物碱含量较高。 这些是防御性化合物,可防止昆虫、感染和……饥饿的动物。 早期的农民选择苦配糖生物碱含量低的品种,这是大多数现代土豆的祖先,但他们并没有放弃高配糖生物碱品种。 它们更耐寒,更能忍受高海拔、寒冷的气温和害虫。 生活在安第斯山脉高处的文化开发了一种方法来利用这些耐寒但有毒的土豆,以及他们自己恶劣的气候:他们发明了chuños。 这些是通过将土豆放在露天制成的,它们在晚上冷冻,踩在脚下并在阳光下晒很多天。 做成一种配糖生物碱含量低的干薯,可以储存一年或更长时间。
Nutritional Qualities营养质量
From a nutritional standpoint, potatoes have a bad reputation, but this is undeserved in my opinion. If I had to pick a single food to eat exclusively for an extended period of time, potatoes would be high on the list. One reason is that they contain an adequate amount of complete protein, meaning they don't have to be mixed with another protein source as with grains and legumes. Another reason is that a number of cultures throughout history have successfully relied on the potato as their principal source of calories, and several continue to do so. A third reason is that they're eaten in an unrefined, fresh state.
从营养的角度来看,土豆的名声很差,但在我看来这是不应该的。 如果我不得不选择一种食物专门吃很长一段时间,土豆会在名单上名列前茅。 一个原因是它们含有足量的完整蛋白质,这意味着它们不必像谷物和豆类那样与另一种蛋白质来源混合。 另一个原因是,历史上的许多文化都成功地将土豆作为热量的主要来源,并且有一些文化还在继续这样做。 第三个原因是它们是在未精制的新鲜状态下食用的。
Potatoes contain an adequate amount of many essential minerals, and due to their low phytic acid content (1), the minerals they contain are well absorbed. They're rich in magnesium and copper, two minerals that are important for insulin sensitivity and cardiovascular health (2, 3). They're also high in potassium, which helps control blood pressure, and vitamin C. Overall, they have a micronutrient content that compares favorably with other starchy root vegetables such as taro and cassava (4, 5, 6), and they offer considerably more micronutrients than refined carbohydrates such as white flour, white rice and white sugar.
土豆含有足量的多种必需矿物质,而且由于其植酸含量低,它们所含的矿物质很容易被吸收。它们富含镁和铜,这两种矿物质对胰岛素敏感性和心血管健康很重要。 它们的钾含量也很高,有助于控制血压和维生素C。总的来说,它们的微量营养素含量与芋头和木薯等其他淀粉类根菜类蔬菜相比更胜一筹,并且它们提供了相当多的比精制碳水化合物(如白面粉、白米和白糖)更多的微量营养素。
On the other hand, I don't have to eat potatoes exclusively, so what do they have to offer a mixed diet? They have a high glycemic index, which means they raise blood sugar more than an equivalent serving of most carbohydrate foods, although I'm not convinced that's a problem in people with good blood sugar control (7, 8). They contain adequate fiber, but less than some other sources of starch. For example, sweet potatoes, an unrelated species, contain more micronutrients and fiber, and have been a central food source for healthy cultures (9). However, the main reasons temperate-climate cultures throughout the world eat potatoes is they yield well, they're easily digested, they fill you up and they taste good.
另一方面,不需要只吃土豆,把它们作为混合饮食中的一部分。它们具有高血糖指数,这意味着它们比同等份量的大多数碳水化合物食物更能提高血糖,尽管我不相信这对血糖控制良好的人来说是一个问题。 它们含有足够的纤维,但少于其他一些淀粉来源。 例如红薯,一种不相关的物种,含有更多的微量营养素和纤维,并且一直是健康文化的主要食物来源。 然而,世界各地的温带气候文化食用土豆的主要原因是它们产量高、容易消化、能填饱肚子而且味道很好。
* In terms of calories produced per acre.
* 以每英亩产生的卡路里计算。
A simplified description. The process can actually be rather involved, with several different drying, stomping and leaching steps 简化说明。 这个过程实际上可能相当复杂,有几个不同的干燥、跺脚和浸出步骤
Glycoalkaloids in Commonly Eaten Potatoes土豆中的糖苷生物碱
Like many edible plants, potatoes contain substances designed to protect them from marauding creatures. The main two substances we're concerned with are alpha-solanine and alpha-chaconine, because they are the most toxic and abundant. Here is a graph of the combined concentration of these two glycoalkaloids in common potato varieties (1):
与许多可食用植物一样,土豆含有旨在保护它们免受掠夺生物侵害的物质。 我们关注的主要两种物质是α-茄碱和α-查茄碱,因为它们的毒性和含量最高。 这是这两种配糖生物碱在常见土豆品种中的总浓度图:
We can immediately determine three things from this graph:
我们可以立即从这张图中确定三件事:
* 不同的品种含有不同量的糖苷生物碱。
* 常见的商业品种,如赤褐色和白土豆,其配糖生物碱含量较低。
* 大部分配糖生物碱含量在土豆皮中(距离表面1毫米以内)。 幸运的是,人类有削皮器。
I'll jump the gun and tell you that the generally accepted safe level of potato glycoalkaloids is 200 mcg/g fresh weight (1). You can see that all but one variety are well below this level when peeled. Personally, I've never seen the Snowden variety in the store or at the farmer's market. It appears to be used mostly for potato chips.
我直接告诉你,土豆糖苷生物碱的普遍接受的安全水平是200mcg/g鲜重。 你可以看到,去皮时,除了一个品种外,所有品种都远低于这个水平。就个人而言,我从未在商店或农贸市场看到过斯诺登品种。 它似乎主要用于薯片。
Glycoalkaloid Toxicity in Animals动物体内的糖苷生物碱毒性
Potato glycoalkaloids are undoubtedly toxic at high doses. They have caused many harmful effects in animals and humans, including (1, 2):
土豆配糖生物碱在高剂量时无疑是有毒的。 它们对动物和人类造成了许多有害影响,包括:
* 死亡(人类和动物)
* 体重减轻、腹泻(人和动物)
* 贫血(兔子)
* 肝损伤(大鼠)
* 较低的出生体重(小鼠)
* 出生缺陷(注射配糖生物碱的动物)
* 增加肠道通透性(小鼠)
However, it's important to remember the old saying “the dose makes the poison”. The human body is designed to handle a certain amount of plant toxins with no ill effects. Virtually every plant food, and a few animal foods, contains some kind of toxic substance. We're constantly bombarded by gamma rays, ultra violet rays, bacterial toxins, free radicals, and many other potentially harmful substances. In excess, they can be deadly, but we are adapted to dealing with small amounts of them, and the right dose can even be beneficial in some cases.
然而,重要的是要记住一句老话“剂量成毒”。 人体旨在处理一定量的植物毒素而不会产生不良影响。 几乎每一种植物性食物,以及一些动物性食物,都含有某种有毒物质。 我们不断受到伽马射线、紫外线、细菌毒素、自由基和许多其他潜在有害物质的轰击。 过量让它们可能是致命的,但我们已经适应了处理少量它们,在某些情况下,正确的剂量甚至可能是有益的。
All of the studies I mentioned above, except one, involved doses of glycoalkaloids that exceed what one could get from eating typical potatoes. They used green or blemished potatoes, isolated potato skins, potato sprouts or isolated glycoalkaloids (more on this later). The single exception is the last study, showing that normal doses of glycoalkaloids can aggravate inflammatory bowel disease in transgenic mice that are genetically predisposed to it (3)*.
我上面提到的所有研究,除了一项,涉及的糖生物碱剂量超过了吃典型土豆所能获得的剂量。他们使用绿色或有瑕疵的土豆、分离的土豆皮、土豆芽或分离的糖苷生物碱(稍后会详细介绍)。唯一的例外是最后一项研究,该研究表明,正常剂量的糖苷生物碱会加重具有遗传倾向的转基因小鼠的炎症性肠病*。
What happens when you feed normal animals normal potatoes? Not much. Many studies have shown that they suffer no ill effects whatsoever, even at high intakes (1, 2). This has been shown in primates as well (4, 5, 6). In fact, potato-based diets appear to be generally superior to grain-based diets in animal feed. As early as 1938, Dr. Edward Mellanby showed that grains, but not potatoes, aggravate vitamin A deficiency in rats and dogs (7). This followed his research showing that whole grains, but not potatoes, aggravate vitamin D deficiency due to their high phytic acid content (Mellanby. Nutrition and Disease. 1934). Potatoes were also a prominent part of Mellanby's highly effective tooth decay reversal studies in humans, published in the British Medical Journal in 1932 (8, 9).
当你喂普通动物普通土豆时会发生什么? 不多。 许多研究表明,即使摄入量很高,它们也不会受到任何不良影响。这在灵长类动物中也得到了证明。 事实上,在动物饲料中,以土豆为基础的饮食似乎普遍优于以谷物为基础的饮食。早在1938年,Edward Mellanby博士就表明谷物会加重大鼠和狗的维生素A缺乏症,而不是土豆。 在此之前,他的研究表明,全谷物,而不是土豆,由于其植酸含量高,会加剧维生素 D 缺乏症。 土豆也是Mellanby高效逆转人类蛀牙研究的重要组成部分,该研究于1932年发表在英国医学杂志上。
Potatoes partially protect rats against the harmful effects of excessive cholesterol feeding, when compared to wheat starch-based feed (10). Potato feeding leads to a better lipid profile and intestinal short-chain fatty acid production than wheat starch or sugar in rats (11). I wasn't able to find a single study showing any adverse effect of normal potato feeding in any normal animal.
与小麦淀粉基饲料相比,土豆可部分保护大鼠免受过量胆固醇喂养的有害影响。 在大鼠中,与小麦淀粉或糖相比,土豆喂养导致更好的脂质分布和肠道短链脂肪酸的产生。 我无法找到一项研究表明,任何正常动物的正常土豆喂养有任何不利影响。
*Interleukin-10 knockout mice. IL-10 is a cytokine involved in the resolution of inflammation and these mice develop inflammatory bowel disease (regardless of diet) due to a reduced capacity to resolve inflammation.
*Interleukin-10 基因敲除小鼠。 IL-10是一种参与炎症消退的细胞因子,由于消炎能力降低,这些小鼠会患上炎症性肠病(无论饮食如何)。
Potato-eating Cultures: the Quechua吃土豆的文明:克丘亚人
The potato is thought to have originated in what is now Peru, on the shores of lake Titicaca. Native Peruvians such as the Quechua have been highly dependent on the potato for thousands of years. A 1964 study of the Quechua inhabitants of Nuñoa showed that they obtained 74% of their calories from potatoes (fresh and chuños), 10% from grains, 10% from Chenopodia (quinoa and cañihua), and 4% from animal foods. Total energy intake was 3,170 calories per day (1).
土豆被认为起源于现在的秘鲁,在的喀喀湖沿岸。数千年来,克丘亚人等秘鲁本土人一直高度依赖土豆。1964年对Nuñoa克丘亚居民的一项研究表明,他们74%的卡路里来自土豆(新鲜和chuños),10% 来自谷物,10% 来自藜麦和 cañihua,4%来自动物食品。总能量摄入量为每天3,170卡路里。
In 2001, a medical study of rural Quechua men reported an average body fat percentage of 16.4% (2). The mean age of the volunteers was 38. Body fat did increase slowly with age in this population, and by age 65 it was predicted to be about 20% on average. That's below the threshold of overweight, so I conclude that most men in this population are fairly lean, although there were a few overweight individuals.
2001年,一项针对农村克丘亚族男性的医学研究报告称,平均体脂百分比为16.4%。 志愿者的平均年龄为38岁。在这个人群中,身体脂肪确实随着年龄的增长缓慢增加,预计到65岁时平均增加约20%。这低于超重的门槛,所以我得出结论,尽管有一些超重的人,但这个人群中的大多数男性都相当瘦。
In 2004, a study in rural Quechua women reported a body fat percentage of 31.2% in volunteers with a mean age of 35 (3). Body fat percentage was higher in a group of Quechua immigrants to the Peruvian capital of Lima. Among rural women, average fasting insulin was 6.8 uIU/mL, and fasting glucose was 68.4 mg/dL, which together suggest good insulin sensitivity and glucose control (4). Insulin and glucose were considerably lower in the rural group than the urban group. Blood pressure was low in both groups. Overall, this suggests that overweight is common among Quechua women.
2004 年,一项针对农村克丘亚族妇女的研究报告称,平均年龄为35岁的志愿者的体脂百分比为31.2%。 一群前往秘鲁首都利马的克丘亚族移民的体脂百分比更高。 在农村妇女中,平均空腹胰岛素为6.8uIU/mL,空腹血糖为68.4mg/dL,这表明胰岛素敏感性和血糖控制良好。 农村组的胰岛素和葡萄糖明显低于城市组。两组的血压均较低。总体而言,这表明超重在克丘亚族女性中很常见。
Rural Quechua are characteristically short, with the average adult man standing no more than 5' 2“ (2). One might be tempted to speculate that this reflects stunting due to a deficient diet. However, given the fact that nearly all non-industrial populations, including contemporary hunter-gatherers, are short by modern standards, I'm not convinced the Quechua are abnormal. A more likely explanation is that industrial foods cause excessive tissue growth in modern populations, perhaps by promoting overeating and excessive insulin and IGF-1 production, which are growth factors. I first encountered this hypothesis in Dr. Staffan Lindeberg's book Food and Western Disease.
农村克丘亚人的特点是矮小,成年男子的平均身高不超过5英尺2英寸。人们可能会猜测这反映了由于饮食不足导致发育迟缓。然而,鉴于几乎所有非工业,包括当代狩猎采集者在内的人口以现代标准衡量都很矮,我不相信克丘亚人是异常的。一个更可能的解释是工业食品导致现代人口组织过度生长,可能是通过促进暴饮暴食和过量的胰岛素和IGF- 1生产,它们是生长因子。我第一次遇到这个假设是在Staffan Lindeberg博士的书《食物与西方疾病》中。
I don't consider the Quechua diet to be optimal, but it does seem to support a reasonable level of metabolic health. Rural Quechua men subsisting on potatoes are relatively lean, while women are often overweight, though less overweight than urban Quechua who eat fewer potatoes. Unfortunately, I don't have more detailed data on other aspects of their health, such as gastrointestinal health.
我不认为克丘亚饮食是最佳的,但它似乎支持合理水平的代谢健康。 以土豆为生的农村克丘亚人相对瘦弱,而女性通常超重,但比吃土豆少的城市克丘亚人的超重要轻。 不幸的是,我没有关于他们健康其他方面的更详细数据,例如胃肠道健康。
Potato-eating Cultures: the Aymara吃土豆的文明:艾马拉人
The Aymara are another potato-dependent people of the Andes, who span Peru, Bolivia and Chile. The first paper I'll discuss is titled “Low Prevalence of Type II Diabetes Despite a High Body Mass Index in the Aymara Natives From Chile”, by Dr. Jose Luis Santos and colleagues (5). In the paper, they show that the prevalence of diabetes in this population was 1.5%, and the prevalence of pre-diabetes was 3.6%. The prevalence of both remained low even in the elderly. Here's a comparison of those numbers with figures from the modern United States (6):
艾马拉人是安第斯山脉的另一个依赖土豆的人,他们横跨秘鲁、玻利维亚和智利。我将讨论的第一篇论文由Jose Luis Santos博士及其同事撰写,标题为“尽管来自智利的Aymara土著人的体重指数较高,但二型糖尿病的患病率较低” 。在论文中,他们表明该人群的糖尿病患病率为1.5%,糖尿病前期患病率为3.6%。 即使在老年人中患病率仍然很低。以下是这些数字与现代美国的数字的比较:
That's quite a difference! The prevalence of diabetes in this population is low, but not as low as in some cultures such as the Kitavans (7, 8).
那是相当的不同!该人群中糖尿病的患病率较低,但并不像Kitavans等一些文化中那样低。
Now to discuss the “high body mass index” referenced in the title of the paper. The body mass index (BMI) is the relation between height and weight, and often, but not always, reflects fatness. The average BMI of this population was 24.9, which is very close to the cutoff between normal and overweight (25).
现在来讨论论文标题中提到的“高体重指数”。 体重指数 (BMI) 是身高和体重之间的关系,通常但并非总是反映肥胖。该人群的平均BMI为24.9,非常接近正常体重和超重之间的分界值。
Investigators were surprised to find such a low prevalence of diabetes in this population, despite their apparent high prevalence of overweight. Yet if you've seen pictures of rural native South Americans, you may have noticed they're often built short and thick, with wide hips and big barrel chests. Could this be confounding the relationship between BMI and body fatness? To answer that question, I found another paper that estimated Aymara body fat using skinfold measurements (9). That study reported that both men and women remained relatively lean throughout life (ages 4-65), with only two of 23 subjects classified as overweight on the basis of body fat percentage, and none classified as obese.
调查人员惊讶地发现,这一人群中糖尿病的患病率如此之低,尽管他们的超重患病率明显很高。 然而,如果你看过南美农村原住民的照片,你可能已经注意到他们通常身材矮小,臀部宽阔,桶形胸大。 这是否会混淆BMI和体脂之间的关系? 为了回答这个问题,我发现了另一篇论文,该论文使用皮褶测量来估计艾马拉人的身体脂肪。 该研究报告称,男性和女性终其一生(4-65 岁)都保持相对瘦弱的状态,根据体脂百分比,23名受试者中只有两名被归类为超重,没有人被归类为肥胖。
Back to the first paper. In this Aymara group, blood pressure was on the high side. Serum cholesterol was also a bit high for a traditionally-living population, but still lower than most modern groups (~188 mg/dL). I find it very interesting that the cholesterol level in this population that eats virtually no fat was the same as on Tokelau, where nearly half of calories come from highly saturated coconut fat (10, 11). Fasting insulin is also on the high side in the Aymara, which is also interesting given their good glucose tolerance and low prevalence of diabetes. This could be related to differences in the measurement assay rather than a true difference in fasting insulin, since these assays were often not standardized between studies.
回到第一篇论文。 在这个艾马拉组中,血压偏高。 对于传统生活的人群,血清胆固醇也有点高,但仍低于大多数现代人群(~188 mg/dL)。 我发现非常有趣的是,这个几乎不吃脂肪的人群中的胆固醇水平与托克劳相同,那里将近一半的卡路里来自高度饱和的椰子脂肪。 空腹胰岛素在艾马拉人也偏高,鉴于其良好的葡萄糖耐受性和低糖尿病患病率,这也很有趣。这可能与测量测定的差异有关,而不是空腹胰岛素的真正差异,因为这些测定在研究之间通常没有标准化。
Together, this shows that a lifetime of high-carbohydrate, high-glycemic food does not necessarily lead to overweight or metabolic problems in the context of a traditional diet and lifestyle.
总之,这表明在传统饮食和生活方式的背景下,终生食用高碳水化合物、高血糖的食物不一定会导致超重或代谢问题。
Potato-eating Cultures: the Irish吃土豆的文明:爱尔兰人
Potatoes were introduced to Ireland in the 17th century. They were well suited to the cool, temperate climate, and more productive than any other crop. By the early 18th century, potatoes were the main source of calories, particularly for the poor who ate practically nothing else. In 1839, the average Irish laborer obtained 87% of his calories from potatoes (12). In 1845, the potato blight Phytophthora infestans struck, decimating potato plantations nationwide and creating the Great Famine.
土豆17世纪传入爱尔兰。它们非常适合凉爽、温带的气候,而且比任何其他作物的产量都更高。到18世纪早期,土豆是卡路里的主要来源,特别是对于几乎不吃其他食物的穷人而言。1839年爱尔兰工人平均87%的卡路里来自土豆。1845年土豆疫病致病疫霉袭击了全国的土豆种植园,并造成了大饥荒。
There isn't much reliable information on the health status of the Irish prior to the famine, besides reports of vitamin A deficiency symptoms (13) due to the fact that neither of the primary articles of diet, potatoes and buttermilk, provide significant vitamin A. However, the Irish at the time had a very high fertility rate, and anecdotal reports described them as healthy and attractive (14):
关于饥荒前爱尔兰人的健康状况没有太多可靠的信息,除了维生素A缺乏症状的报告,因为主要的饮食、土豆和酪乳都没有提供大量的维生素A。然而,当时的爱尔兰人生育率非常高,传闻称他们健康而有吸引力:
As far as fecundity is concerned, the high nutritional value of the potato diet might have played a significant role, but little supportive evidence has been presented so far… What is known is that the Irish in general and Irish women in particular were widely described as healthy and good-looking. Adam Smith's famous remark that potatoes were “peculiarly suitable to the health of the human constitution” can be complemented with numerous observations from other contemporary observers to the same effect.
就繁殖力而言,土豆饮食的高营养价值可能发挥了重要作用,但迄今为止几乎没有提供支持性证据……众所周知的是,爱尔兰人,尤其是爱尔兰妇女,普遍被形容健康又好看。 亚当·斯密(Adam Smith) 的名言土豆“特别适合人类体质的健康”,可以用其他当代观察家的大量观察来补充,以达到相同的效果。
Controlled Feeding Studies控制喂养研究
Starting nearly a century ago, a few researchers decided to feed volunteers potato-only diets to achieve various research objectives. The first such experiment was carried out by a Dr. M. Hindhede and published in 1913 (described in 15). Hindhede's goal was to explore the lower limit of the human protein requirement and the biological quality of potato protein. He fed three healthy adult men almost nothing but potatoes and margarine for 309 days (margarine was not made from hydrogenated seed oils at the time), all while making them do progressively more demanding physical labor. They apparently remained in good physical condition. Here's a description of one of his volunteers, a Mr. Madsen, from another book (described in 16; thanks to Matt Metzgar):
从近一个世纪前开始,一些研究人员决定为志愿者提供纯土豆饮食,以实现各种研究目标。 第一个这样的实验是由M. Hindhede博士进行的,并于1913年发表。 Hindhede的目标是探索人类蛋白质需求的下限和土豆蛋白质的生物学品质。 在309天里,他几乎只给三个健康的成年男性喂食土豆和人造黄油(人造黄油当时不是由氢化种子油制成),同时让他们做越来越苛刻的体力劳动。 他们显然保持良好的身体状况。 这是他的一位志愿者Madsen先生的描述,来自另一本书:
In order to test whether it was possible to perform heavy work on a strict potato diet, Mr. Madsen took a place as a farm laborer… His physical condition was excellent. In his book, Dr. Hindhede shows a photograph of Mr. Madsen taken on December 21st, 1912, after he had lived for almost a year entirely on potatoes. This photograph shows a strong, solid, athletic-looking figure, all of whose muscles are well-developed, and without excess fat. …Hindhede had him examined by five physicians, including a diagnostician, a specialist in gastric and intestinal diseases, an X-ray specialist, and a blood specialist. They all pronounced him to be in a state of perfect health.
为了测试严格的土豆饮食是否可以从事繁重的工作,马德森先生找了一份农场工人的工作……他的身体状况非常好。 在他的书中,欣德赫德博士展示了马德森先生于1912年12月21日拍摄的照片,当时他完全靠土豆生活了将近一年。 这张照片显示了一个强壮、结实、运动型的身材,他的所有肌肉都很发达,没有多余的脂肪。Hindhede让他接受了五位医生的检查,其中包括一名诊断师、一名胃和肠道疾病专家、一名X射线专家和一名血液专家。 他们都宣布他处于完美的健康状态。
Dr. Hindhede discovered that potato protein is high quality, providing all essential amino acids and high digestibility. Potato protein alone is sufficient to sustain an athletic man (although that doesn't make it optimal). A subsequent potato feeding study published in 1927 confirmed this finding (17). Two volunteers, a man and a woman, ate almost nothing but potatoes with a bit of lard and butter for 5.5 months. The man was an athlete but the woman was sedentary. Body weight and nitrogen balance (reflecting protein gain/loss from the body) remained constant throughout the experiment, indicating that their muscles were not atrophying at any appreciable rate, and they were probably not putting on fat. The investigators remarked:
Hindhede博士发现土豆蛋白质质量高,提供所有必需氨基酸和高消化率。仅土豆蛋白质就足以维持一个运动健将(尽管这并不能使其达到最佳状态)。 随后发表于1927年的土豆喂养研究证实了这一发现。两名志愿者,一个男人和一个女人,在5.5个月的时间里,几乎什么都不吃,只吃土豆加一点猪油和黄油。男人是运动员,但女人久坐不动。体重和氮平衡(反映身体蛋白质的增加/减少)在整个实验过程中保持不变,表明他们的肌肉没有以任何明显的速度萎缩,而且他们可能没有增加脂肪。调查人员表示:
The digestion was excellent throughout the experiment and both subjects felt very well. They did not tire of the uniform potato diet and there was no craving for change.
整个实验过程中消化非常好,两个受试者都感觉很好。他们不厌倦统一的土豆饮食,也不渴望改变。
In one of his Paleo Diet newsletters titled “Consumption of Nightshade Plants (Part 1)”, Dr. Loren Cordain referenced two feeding studies showing that potatoes increase the serum level of the inflammatory cytokine interleukin-6 (22, 23). However, one study was not designed to determine the specific role of potato in the change (two dietary factors were altered simultaneously), and the other used potato chips as the source of potato. So I don't find these studies particularly relevant to the question at hand.
在他的一篇题为“茄属植物的消耗”的Paleo Diet通讯中,Loren Cordain博士引用了两项喂养研究,这些研究表明土豆会增加炎症细胞因子白细胞介素6的血清水平。 然而,一项研究并非旨在确定土豆在变化中的具体作用(两个饮食因素同时改变),另一项研究使用薯片作为来源。所以我不认为这些研究与手头的问题特别相关。
Just yesterday, Chris Voigt of the Washington State Potato Commission embarked on his own n=1 potato feeding experiment as a way to promote Washington state potatoes. He'll be eating nothing but potatoes and a little fat for two months, and getting a full physical at the end. Check out his website for more information and updates (18). Mr. Voigt has graciously agreed to a written interview with Whole Health Source at the end of his experiment. He pointed out to me that the Russet Burbank potato, the most popular variety in the United States, is over 135 years old. Stay tuned for more interesting facts from Mr. Voigt in early December.
就在昨天,华盛顿州土豆委员会的Chris Voigt开始了他自己的n=1土豆喂养实验,作为推广华盛顿州土豆的一种方式。他将在两个月内只吃土豆和一点点脂肪,最后会恢复体力。查看他的网站以获取更多信息和更新。Voigt先生慷慨地同意在他的实验结束时接受Whole Health Source的书面采访。他向我指出,美国最受欢迎的品种Russet Burbank土豆已有135年的历史。请继续关注Voigt先生在12月初的更多有趣事实。
Observational Studies观察研究
With the recent interest in the health effects of the glycemic index, a few studies have examined the association between potatoes and health in various populations. The results are all over the place, with some showing positive associations with health, and others showing negative associations (19, 20, 21). As a whole, I find these studies difficult to interpret and not very helpful.
随着最近对血糖指数对健康影响的兴趣,一些研究检查了土豆与不同人群健康之间的关系。结果无处不在,有些与健康呈正相关,有些则与健康呈负相关。总的来说,我发现这些研究很难解释,也不是很有帮助。
Anecdotes轶事
Some people feel good when they eat potatoes. Others find that potatoes and other members of the nightshade family give them digestive problems, exacerbate their arthritis, or cause fat gain. I haven't encountered any scientific research to substantiate claims that nightshades aggravate arthritis or other inflammatory conditions. However, that doesn't necessarily mean there aren't individuals who are sensitive. If potatoes don't agree with you, by all means avoid them.
有些人吃土豆时感觉很好。 其他人发现土豆和茄属植物的其他成员会给他们带来消化问题、加剧关节炎或导致脂肪增加。 我还没有遇到任何科学研究来证实茄属植物会加重关节炎或其他炎症的说法。 然而,这并不一定意味着没有敏感的人。但如果你吃了土豆后不舒服,那一定要避开它们。
The Bottom Line底线
In my opinion, the scientific literature as a whole, including animal and human studies, suggests rather consistently that potatoes can be a healthy part of a varied diet for most people, and they probably do not generally promote digestive problems, fat gain, or metabolic dysfunction. Nevertheless, I wouldn't recommend eating nothing but potatoes for any length of time. If you do choose to eat potatoes, follow these simple guidelines:
在我看来,包括动物和人类研究在内的整个科学文献一致表明,土豆可以成为大多数人多样化饮食的健康组成部分,它们通常不会导致消化问题、脂肪增加或代谢问题。 功能障碍。 尽管如此,我不建议在任何时间内只吃土豆。 如果您确实选择吃土豆,请遵循以下简单指南:
* 不要吃发绿、发芽、有污点或损坏的土豆
* 将它们存放在阴凉、黑暗的地方。它们不需要冷藏,但会冷藏(3-5度)可以延长它们的寿命
* 如果您把它们作为主食,请在食用前将它们削皮
Enjoy your potatoes!
鲨补充:不要把土豆在PUFA中烹饪,toxic。
斯蒂芬·古内特 Stephan Guyenet
一万多年前,在现在秘鲁的的喀喀湖沿岸,开始种植野生土豆。他们逐渐将其转化为能够有效地生产圆形淀粉块茎的植物,品种多样,适合不同人群的气候和美食需求。 这些早期的农民当时不会知道他们选择的植物会成为世界上产量最高的作物*,最终养活全球数十亿人。
野生土豆在驯化前很可能被狩猎采集者食用,有毒茄碱含量较高。 茄碱是防御性化合物,可防止昆虫、感染和饥饿的动物。 早期的农民选择茄碱含量低的品种,这是大多数现代土豆的祖先,但并没有放弃高茄碱品种,这些更耐寒,更能忍受高海拔、寒冷的气温和害虫。 生活在安第斯山脉高处的人们开发了一种方法来利用这些耐寒但有毒的土豆,以及利用恶劣的气候发明了他们的薯片, 将土豆放在露天制成的薯片,在晚上冷冻,踩在脚下在阳光下晒很多天 * *,做成一种茄碱含量低的土豆干,可以储存一年或更长时间。
从营养的角度来看,土豆的名声差,但在我看来这是不应该的。 如果我不得不选择一种食物专门吃很长一段时间,土豆会在名单上排前列。 一个原因是土豆含有足量的完整蛋白质,这意味着土豆不必像谷物和豆类那样与另一种蛋白质来源混合。 另一个原因是,历史上的许多文化都成功地将土豆作为热量的主要来源,有一些还在继续这样。 第三个原因是土豆是可在未精制的新鲜状态下食用的。
土豆含有足量的多种必需矿物质,由于植酸含量低,所含的矿物质很容易被吸收。土豆富含镁和铜,这两种矿物质对胰岛素敏感性和心血管健康很重要。 钾含量也很高,有助于控制血压和维生素C。总的来说,土豆的微量营养素含量与芋头和木薯等其他淀粉类根菜类蔬菜相比更胜一筹,并且大量提供比精制碳水(如白面粉、白米和白糖)更多的微量营养素。
另一方面,不需要只吃土豆,把土豆作为混合饮食中的一部分。土豆具有高血糖指数,意味着比同等份量的大多数碳水食物更能提高血糖,尽管我不相信这对血糖控制良好的人来说是一个问题。 土豆含有足够的纤维,但少于其他一些淀粉来源,例如红薯是一种不相关的物种,含有更多的微量营养素和纤维,一直是健康文化的主要食物来源。 然而世界各地的温带气候文化食用土豆的主要原因土豆产量高、容易消化、能填饱肚子而且味道很好。
* 以每英亩产生热量计算。
* * 简化说明。 这个过程实际上可能相当复杂,有几个不同的干燥、跺脚和浸出步骤
Like many edible plants, potatoes contain substances designed to protect them from marauding creatures. The main two substances we're concerned with are alpha-solanine and alpha-chaconine, because they are the most toxic and abundant. Here is a graph of the combined concentration of these two glycoalkaloids in common potato varieties (1):
土豆与许多可食用植物一样,含有旨在保护免受掠夺生物侵害的物质。 主要关注的两种物质是α-茄碱和α-查茄碱,因为其毒性和含量最高。下面是这两种茄碱在常见土豆品种中的总浓度图:
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可以立即从这张图中确定:
I'll jump the gun and tell you that the generally accepted safe level of potato glycoalkaloids is 200 mcg/g fresh weight (1). You can see that all but one variety are well below this level when peeled. Personally, I've never seen the Snowden variety in the store or at the farmer's market. It appears to be used mostly for potato chips.
我直接告诉你,土豆的糖苷生物碱普遍接受的安全水平是鲜重 200mcg/g。 可以看到,除了一个品种外,去皮后所有品种都远低于这个水平。就个人而言,我从未在商店或菜场看到过斯诺登品种,似乎主要用于薯片。
Potato glycoalkaloids are undoubtedly toxic at high doses. They have caused many harmful effects in animals and humans, including (1, 2):
土豆茄碱在高剂量时无疑是有毒的,对动物和人类造成了许多有害影响,包括:
然而,重要的是要记住一句老话“离开剂量不谈毒性”。 人类的身体被设计为处理一定量的植物毒素而没有不良影响。 几乎每一种植物性食物,以及一些动物性食物,都含有某种有毒物质。 我们不断受到伽马射线、紫外线、细菌毒素、自由基和许多其他潜在有害物质的轰击。 过量可能是致命的,但我们已经适应了处理少量毒素,在某些情况下,合适的剂量甚至可能是有益的。
我上面提到的所有研究,除了一项,涉及的糖生物碱剂量超过了吃典型土豆所能获得的剂量。他们使用绿色或有瑕疵的土豆、分离的土豆皮、土豆芽或分离的糖苷生物碱(稍后会详细介绍)。唯一的例外是最后一项研究,该研究表明,正常剂量的糖苷生物碱会加重具有遗传倾向的转基因小鼠的炎症性肠病*。
给普通动物喂普通土豆时会发生什么? 没什么。 许多研究表明,即使摄入量很高, 也不会受到任何不良影响。这在灵长类动物中也得到了证明。 事实上,在动物饲料中,以土豆为基础的饮食似乎普遍优于以谷物为基础的饮食。早在1938年,爱德华·梅兰比(Edward Mellanby)博士就表明谷物会加重大鼠和狗的维生素A缺乏症,而不是土豆。 在此之前,他的研究表明,全谷物(而非土豆)由于植酸含量高,会加剧维生素 D 缺乏症。 土豆也是梅兰比高效逆转人类蛀牙研究的重要组成部分,该研究于1932年发表在英国医学杂志上。
与小麦淀粉基饲料相比,土豆可部分保护大鼠免受过量胆固醇喂养的有害影响。 在大鼠中,与小麦淀粉或糖相比,土豆喂养导致更好的脂质分布和肠道短链脂肪酸的产生。 我无法找到有研究会表明任何正常动物的正常土豆喂养有任何不利影响。
*Interleukin-10 基因敲除小鼠。 IL-10是一种参与炎症消退的细胞因子,由于消炎能力降低,这些小鼠会患上炎症性肠病(无论饮食如何)。
土豆被认为起源于现在的秘鲁喀喀湖沿岸。数千年来,克丘亚人等秘鲁土著人一直高度依赖土豆。1964年对努诺阿的克丘亚居民的一项研究表明,74%的热量来自土豆(新鲜和晒干),10% 来自谷物,10% 来自藜麦和苍白藜,4%来自动物食品。总能量摄入量为每天3,170卡。
2001年,一项针对农村克丘亚族男性的医学研究报告称,平均体脂百分比为16.4%。 志愿者的平均年龄为38岁。在这个人群中,体脂确实随着年龄的增长缓慢增加,预计到65岁时平均增加约20%。低于超重的门槛,所以我得出结论,尽管有一些超重的人,但这个人群中的大多数男性都相当瘦。
2004 年,一项针对农村克丘亚族妇女的研究报告称,平均年龄为35岁的志愿者的体脂百分比为31.2%。 一群前往秘鲁首都利马的克丘亚族移民的体脂百分比更高。 在农村妇女中,平均空腹胰岛素为6.8uIU/mL,空腹血糖为68.4mg/dL,这表明胰岛素敏感性和血糖控制良好。 农村组的胰岛素和葡萄糖明显低于城市组。两组的血压均较低。总体而言,这表明超重在克丘亚族女性中很常见。
农村克丘亚人的特点是矮小,成年男子的平均身高不超过5英尺2英寸。人们可能会猜测这反映了由于饮食不足导致发育迟缓。然而,鉴于几乎所有非工业包括当代狩猎采集者在内的人口以现代标准衡量都很矮,我不相信克丘亚人是异常的。一个更可能的解释是工业化食品导致现代人组织过度生长,可能是通过促进暴食和过量的胰岛素和生长因子IGF- 1的生产。我第一次遇到这个假设是在斯塔凡·林德伯格(Staffan Lindeberg)博士的书《食物与西方疾病》中。
我不认为克丘亚饮食是最佳的,但似乎支持合理水平的代谢健康。 以土豆为生的乡村克丘亚男性相对瘦弱,女性通常超重,但比吃土豆少的城市克丘亚人的超重要轻。 不幸的是,我没有关于他们健康其他方面的更详细数据,例如胃肠道健康。
艾马拉人是安第斯山脉的另一个依赖土豆的人群,横跨秘鲁、玻利维亚和智利。我讨论的第一篇是何塞·路易斯·桑托斯(Jose Luis Santos)博士团队撰写的题为《尽管智利艾马拉土著人的体重指数较高但二型糖尿病的患病率较低》论文,表明该人群的糖尿病患病率为1.5%,糖尿病前期患病率为3.6%。 即使在老年人中患病率仍然很低。以下是这些数字与现代美国的数字的比较:
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这是相当大的差别!该人群中糖尿病的患病率较低,但并不像基塔瓦(Kitavans)等一些文化中那样低。
现在来讨论论文标题中提到的“高体重指数”。 体重指数 (BMI) 是身高和体重之间的关系,通常但并非总是反映肥胖。该人群的平均BMI为24.9,非常接近正常体重和超重之间的分界值。
调查人员惊讶地发现,这一人群中糖尿病的患病率如此之低,尽管超重率明显很高。 然而,如果你看过南美农村原住民的照片,你可能已经注意到他们通常身材矮小,宽臀大胸。 这是否会混淆BMI和体脂之间的关系? 为了回答这个问题,我发现了另一篇论文,该论文使用皮褶测量来估计艾马拉人的体脂。 该研究报告称,男性和女性终其一生(4-65 岁)都保持相对瘦弱的状态,根据体脂百分比,23名受试者中只有两名被归类为超重,没有人被归类为肥胖。
回到第一篇论文。 在这个艾马拉人群组中,血压偏高。 对于传统生活的人群,血清胆固醇也有点高,但仍低于大多数现代人群(~188 mg/dL)。 我发现非常有趣的是,这个几乎不吃脂肪的人群中的胆固醇水平与托克劳人( Tokelau)相同,托克劳人将近一半的热量来自高度饱和的椰子脂肪。 空腹胰岛素在艾马拉人也偏高,鉴于其良好的葡萄糖耐受性和低糖尿病患病率,这也很有趣。这可能与测量设定的差异有关,而不是空腹胰岛素的真正差异,因为这些测量设定在研究之间通常没有标准化。
总之,这表明在传统饮食和生活方式的背景下,终生食用高碳水、高血糖指数食物不一定会导致超重或代谢问题。
土豆在17世纪传入爱尔兰。土豆非常适合凉爽、温带的气候,比其他任何作物的产量都更高。到18世纪早期,土豆是该地区的热量主要来源,特别是对于几乎不吃其他食物的穷人而言。1839年爱尔兰工人平均87%热量来自土豆。1845年土豆疫病袭击了全国的土豆种植园,并造成了大饥荒。
关于饥荒前爱尔兰人的健康状况没有太多可靠的信息,除了维生素A缺乏症状的报告,因为主要的饮食、土豆和酪乳都没有提供大量的维生素A。然而,当时的爱尔兰人生育率非常高,传闻称其健康而有活力:
就繁殖力而言,土豆饮食的高营养价值可能发挥了重要作用,但迄今为止几乎没有提供支持性证据,众所周知的是,爱尔兰人,尤其是爱尔兰妇女,普遍被形容健康又好看。 亚当·斯密(Adam Smith) 的名言称土豆“特别适合人类体质的健康”,可以用其他当代观察家的大量观察来补充,以达到相同的效果。
从近一个世纪前开始,一些研究人员决定为志愿者提供全土豆饮食,以实现各种研究目标。 第一个这样的实验是由米克尔·欣德赫德(M. Hindhede)博士于1913年发表。 欣德赫德的目标是探索人类蛋白质需求的下限和土豆蛋白质的生物学品质。 在309天里,他几乎给三个健康的成年男性只吃土豆和人造黄油(当时的人造黄油不是由氢化种子油制成),同时让他们做越来越高要求的体力劳动。 他们显然保持良好的身体状况。下面是其中一位志愿者马德森先生的描述,来自另一本书:
为了测试严格的土豆饮食是否可以从事繁重的工作,马德森先生找了一份农场工人的工作……他的身体状况非常好。 在他的书中,欣德赫德博士展示了马德森先生于1912年12月21日拍摄的照片,当时马德森完全靠土豆生活了将近一年。 这张照片显示了一个强壮、结实、运动型的身材,所有肌肉都很发达,没有多余的脂肪。欣德赫德让他接受了五位医生的检查,其中包括一名诊断师、一名胃肠道疾病专家、一名X射线专家和一名血液专家。 他们都宣布他处于完美的健康状态。
欣德赫德博士发现土豆蛋白的质量高,提供所有必需氨基酸和高消化率。仅土豆蛋白就足以维持一个运动健将(尽管这并不能使其达到最佳状态)。 随后发表于1927年的土豆喂养研究证实了这一发现。两名志愿者,一个男性和一个女性,在5个半月的时间里,只吃土豆加一点猪油和黄油。男性是运动员,但女性久坐不动。体重和氮平衡(反映身体蛋白质的增加/减少)在整个实验过程中保持不变,表明他们的肌肉没有以任何明显的速度萎缩,而且他们可能没有增加脂肪。调查人员表示:
整个实验过程中消化非常好,两个受试者都感觉很好。他们不厌倦单一的土豆饮食,也不渴望改变。
在洛伦·科丹(Loren Cordain)博士的一篇题为《茄属植物的摄入》的原始饮食通讯中,引用了两项喂养研究表明土豆会增加炎症细胞因子白细胞介素6的血清水平。 然而,其中一项研究并非旨在确定土豆在变化中的具体作用(两个饮食因素同时改变),另一项研究使用薯片作为来源。所以我不认为这些研究与该问题特别相关。
就在昨天,华盛顿州土豆委员会的克里斯·沃格特(Chris Voigt)开始了自己的n=1土豆实验,作为推广华盛顿州土豆的一种方式。他将在两个月内只吃土豆和一点点脂肪,最后会恢复体力。查看他的网站以获取更多信息和更新。沃格特先生慷慨地同意在他的实验结束时接受我的博客书面采访。他向我指出,美国最受欢迎的品种Russet Burbank土豆已有135年的历史。请继续关注沃格特先生在12月初的更多有趣事实。
随着我最近对血糖指数对健康影响的兴趣,一些研究检查了土豆与不同人群健康之间的关系。结果无处不在,有些与健康呈正相关,有些则与健康呈负相关。总的来说,我发现这些研究很难解释,也不是很有帮助。
有些人吃土豆时感觉很好,有些人发现土豆和茄属植物其他成员会给带来消化问题、加剧关节炎或导致体脂增加。 我还没有遇到任何科学研究来证实茄属植物会加重关节炎或其他炎症的说法。 然而,这并不一定意味着没有敏感的人。但如果你吃了土豆后不舒服,那一定要避开。
在我看来,包括动物和人类研究在内的整个科学文献一致表明,土豆可以成为大多数人多样化饮食的健康组成部分,通常不会导致消化问题、增肥或代谢功能障碍。 尽管如此,我不建议在任何时间范围内只吃土豆。 如果您确实选择吃土豆,请遵循以下简单指南:
享用您的土豆!
鲨补充:不要把土豆在PUFA中烹饪,toxic。
https://zhuanlan.zhihu.com/p/432991884
http://wholehealthsource.blogspot.com/2010/09/potatoes-and-human-health-part-i.html?m=1
http://wholehealthsource.blogspot.com/2010/09/potatoes-and-human-health-part-ii.html?m=1
http://wholehealthsource.blogspot.com/2010/10/potatoes-and-human-health-part-iii.html?m=1
我还没有机会审阅论文(设计、方法等)。看看运动在保持低血糖方面的作用会很有趣。该研究显然将群体分为“城市”和“郊区”,但该帖子没有详细说明这两个群体的久坐/非久坐习惯(必须假设郊区组相当不久坐)。
无论饮食类型如何,高度活跃的个体作为一个整体可能表现出相当低的空腹血糖水平,这当然是可能的。 换句话说,如果你用高蛋白、富含维生素的白面包(或其他一些高升糖食品)代替土豆,结果可能是一样的——假设所有其他东西都一样。 如果在评论(或博客文章中的某处)中回答了这个问题,我很抱歉,我错过了。 [[javascript:;|回复]]