高フォドマップ（FODMAP）食の果糖(フルクトース)について

 

日本「低フォドマップ食」推進会：宇野良治
 

 

「低フォドマップ食」では、果糖（フルクトース）の摂取を制限しています。



 

それは、以下の理由です。
 

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フルクトース（果糖）は、
グルコースの3倍吸収が遅いが、代謝が早いので、グルコースよりも蓄積されやすく高脂血症や肥満、心疾患と関係している。
 

果糖のほとんどは、通常、小腸で吸収され、門脈から肝臓に送られる。
 

そして、
 

　小腸での果糖の吸収が不十分で症状を来すものを「果糖吸収不全症」という。
 

Fructose malabsorption、"dietary fructose intolerance" (DFI)
 

これは、先天的に酵素が欠落している「遺伝性果糖不耐症」とは全く異なる疾患であり、成人に発症するものである。
 

Fructose malabsorption is not to be confused with hereditary fructose intolerance , a potentially fatal condition in which the liver enzymes that break up fructose are deficient.

 

（この疾患については、日本の医学界での認識がほとんどないため、日本の過敏性腸症候群、不明な下痢症、慢性便秘などに、この「果糖吸収不全症」が存在している可能性は少なくないと、私は考えます。この後、そのことが明らかになると予想します。）

 

小腸で吸収されなかった果糖は、大腸に到達し、大腸の腸内細菌により発酵を生じ、水素ガス、メタンガスを発生させる。そのガスによって、さまざまな症状を来す。
 

　症状は、腹部膨満感、下痢や便秘、鼓腸、腹痛、嘔気や嘔吐、うつ症状である。
 

1食で３ｇ以上の果糖は症状を来す可能性があるとされる。
 

Foods with >3 g of fructose per serving are termed a 'high fructose load' and possibly present a risk of inducing symptoms.
 

しかし、果糖と同量のグルコースを含有している果物は、果糖吸収不全症の症状を来しにくいとされている。
 

The USDA food database reveals that many common fruits contain nearly equal amounts of the fructose and glucose, and they do not present problems for those individuals with fructose malabsorption.

 

そのため、低フォドマップ食においては、
 

グルコースよりもフルクトースが多い果実を制限対象としている。
 

Some fruits with a greater ratio of fructose than glucose are apples, pears and watermelon, which contain more than twice as much fructose as glucose.



 

フルクトース吸収不良の管理のための食生活指針 

モナッシュ大学（オーストラリア）では、IBSを有する個人のために、フルクトースの吸収不良を管理するために以下としている。

不利な食品（グルコースより多いフルクトースのある果実など）

·         果物- りんご 、 梨 、 グアバ 、 甘露メロン 、 ナシ梨 、 パパイヤ 、 パパイヤ 、 マルメロ 、 スターフルーツ 、 スイカ 。

·         ドライフルーツ-リンゴ、スグリ、 date 、 イチジク 、ナシ、 レーズン 、 サルタナ 。

·         強化ワイン

·         糖含有食品アガベネクター 、いくつかのコーンシロップ 、濃縮フルーツジュース。

 

また、異性化糖（果糖ぶどう糖液糖など）の摂取も制限しなければなりません
(米国、メイヨークリニックの発信）。

http://www.mayoclinic.org/fructose-intolerance/expert-answers/faq-20058097

 

＜資料＞

http://translate.google.co.jp/translate?hl=ja&sl=en&u=http://en.wikipedia.org/wiki/Fructose_malabsorption&prev=search

 

http://translate.google.co.jp/translate?hl=ja&sl=en&tl=ja&u=http%3A%2F%2Fnourishbyashlyn.com%2Ffructose-malabsorption-the-low-fodmap-diet%2F&anno=2

 

United European Gastroenterol J. 2014 Feb;2(1):14-21. doi: 10.1177/2050640613505279.

Fructose transporters GLUT5 and GLUT2 expression in adult patients with fructose intolerance.

http://www.ncbi.nlm.nih.gov/pubmed/24918004

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J Am Diet Assoc. 2005 Oct;105(10):1559-66.

Fructose intake at current levels in the United States may cause gastrointestinal distress in normal adults.

Beyer PL¹, Caviar EM, McCallum RW.

Author information

Abstract

OBJECTIVE:

Fructose intake has increased considerably in the United States, primarily as a result of increased consumption of high-fructosecorn syrup, fruits and juices, and crystalline fructose. The purpose was to determine how often fructose, in amounts commonly consumed, would result in malabsorption and/or symptoms in healthy persons.

DESIGN:

Fructose absorption was measured using 3-hour breath hydrogen tests and symptom scores were used to rate subjective responses for gas, borborygmus, abdominal pain, and loose stools.

SUBJECTS/SETTING:

The study included 15 normal, free-living volunteers from a medical center community and was performed in a gastrointestinal specialty clinic.

INTERVENTION:

Subjects consumed 25- and 50-g doses of crystalline fructose with water after an overnight fast on separate test days.

MAIN OUTCOME MEASURES:

Mean peak breath hydrogen, time of peak, area under the curve (AUC) for breath hydrogen and gastrointestinal symptoms were measured during a 3-hour period after subjects consumed both 25- and 50-g doses of fructose.

STATISTICAL ANALYSES:

Differences in mean breath hydrogen, AUC, and symptom scores between doses were analyzed using paired t tests. Correlations among peak breath hydrogen, AUC, and symptoms were also evaluated.

RESULTS:

More than half of the 15 adults tested showed evidence of fructose malabsorption after 25 g fructose and greater than two thirds showed malabsorption after 50 g fructose. AUC, representing overall breath hydrogen response, was significantly greater after the 50-g dose. Overall symptom scores were significantly greater than baseline after each dose, but scores were only marginally greater after 50 g than 25 g. Peak hydrogen levels and AUC were highly correlated, but neither was significantly related to symptoms.

CONCLUSIONS:

Fructose, in amounts commonly consumed, may result in mild gastrointestinal distress in normal people. Additional study is warranted to evaluate the response to fructose-glucose mixtures (as in high-fructose corn syrup) and fructose taken with food in both normal people and those with gastrointestinal dysfunction. Because breath hydrogen peaks occurred at 90 to 114 minutes and were highly correlated with 180-minute breath hydrogen AUC, the use of peak hydrogen measures may be considered to shorten the duration of the exam.

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（The Complete Low-FODMAP Diet. Shepherd S, Gibson P）

 

As long as the fructose in a food is balanced with glucose, or there is more glucose than fructose, you can moderate amounts without experiencing IBS symptoms.

Foods are considered a problem for IBS sufferers if they contain more than 0.2 gram fructose in excess of glucose per serving.

Foods and beverages with 0.1 to 0.2 gram more fructose than glucose per serving do not usually induce symptoms.  The main food sources of excess fructose are fruits.

All good things should be enjoyed in moderation.

The gut can b overloaded by lots of fructose even if glucose is in balance with the fructose.

So you should not only choose fruits in which fructose and glucose are in balance, but also limit the amount of such fruit you eat in one sitting. 

The total fruit quantity should be approximately equal to size of an average orange. You can enjoy several servings of fruit per day. But ensure they are spread out, with at least two hours between.