n-3 Fatty Acids

N-3 fatty acids are consists of α linoleic acid derived from cooking oil, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) derived from fish oil. Animals can not synthesize these fatty acids in their body, then the lack of n-3 fatty acids leads to dermatitis. N-3 fatty acids not only compete with n-6 fatty acids but also have its own physiological effect. Therefore, the reference intakes has been set.

Infant

The approximate amount for 0-5 months infant has been set to 0.9 g/d by multiplying the standard mammalian amount 0.78 L/d to n-3 fatty acids concentration of breast milk 1.16 g/L. The approximate amount for 6-11 months infant has been set to 0.8 g/d by calculating the average of the approximate amount of 0-5 months infant and of 1-2 years old child based on the National Health and Nutrition Survey in 2010 and 2011.

Child and Adult

The approximate amount has been set to the median of n-3 fatty acids intake based on the National Health and Nutrition Survey in 2010 and 2011.

Pregnant and Lactation

The approximate amount has been set to 1.8 g/d, the median of n-3 fatty acids intake based on the National Health and Nutrition Survey in pregnant and lactation from 20108 to 2011.

α linoleic acid

There is a report of negative correlation between α linoleic acid and cardiovascular disease, 1 g/d increase of α linoleic acid intake results 10 % decrease of cardiovascular death. However, there are not enough reports for Japanese subject, then the target amount has not been set. Although the risk of prostate cancer, negative association of egg function and negative possibility of fertility have been reported, they are not determined. The effect of long-term intake of α linoleic acid is not clear.

EPA and DHA

The results of meta analysis on the relationship between EPA and DHA and cardiovascular disease is not consisted. The reports for Japanese subject are JPHC, JACC study and JELIS. The intervention study for stroke in Japanese is JELIS, that has shown not primary prevention effect but secondary prevention. There are meta-analysis of breast cancer cohort studies and report of risk reduction in the meta-analysis of colorectal cancer cohort study. In Japanese, decrease of liver cancer incidence and risk reduced of proximal colon cancer has been reported in JPHC. The association between n-3 fatty acid and depression and dementia is not clear.

Fish include such heavy metals as mercury, cadmium, lead and tin and such toxins as PCB and dioxins. There are another criterion for these harmful substances. Therefore, the Dietary Reference Intakes does not take account into these harmful substances.

Although target amount of α-linoleic acid had been set in 2010 edition, it has not been set in 2015 edition. Although they recommended the intake of grater than 1 g/d of EPA and DHA in 2010 edition, they have not been set in 2015 edition.

2015 edition and 2010 edition of the dietary reference of n-3 fatty acids are following table.

The Dietary Reference Intakes of n-3 fatty acids (g/d) (2015 edition)
Gender Male Female
Age Approximate Amount Approximate Amount
0-5 M 0.9 0.9
6-11 M 0.8 0.8
1-2 0.7 0.8
3-5 1.3 1.1
6-7 1.4 1.3
8-9 1.7 1.5
10-11 1.7 1.4
12-14 2.1 1.8
15-17 2.3 1.7
18-29 2.0 1.6
30-49 2.1 1.6
50-69 2.4 2.0
70- 2.2 1.9
Pregnant 1.8
Lactation 1.8
The Dietary Reference Intakes of n-3 fatty acids (g/d) (2010 edition)
Gender Male Female
Age Approximate Amount (g/d) Target Amount (% energy) Approximate Amount (g/d) Target Amount (% energy)
0-5 M 0.9 0.9
6-11 M 0.9 0.9
1-2 0.9 0.9
3-5 1.2 1.2
6-7 1.6 1.3
8-9 1.7 1.5
10-11 1.8 1.7
12-14 2.1 2.1
15-17 2.5 2.1
18-29 ≤ 2.1 ≤ 1.8
30-49 ≤ 2.2 ≤ 1.8
50-69 ≤ 2.4 ≤ 2.1
70- ≤ 2.2 ≤ 1.8
Pregnant 1.9
Lactation 1.7

References:
The Dietary Reference Intakes for Japanese (2015 edition) Lipid (pdf)
The Dietary Reference Intakes for Japanese (2010 edition) Lipid (pdf)

n-3 系脂肪酸

 n-3 系脂肪酸には食用調理油由来の α リノレン酸と魚由来のエイコサペンタエン酸 (EPA), ドコサペンタエン酸 (DPA) およびドコサヘキサエン酸 (DHA) などがあります.これらの脂肪酸は生体内で合成できず,欠乏すると皮膚炎を発症します.n-3 系脂肪酸の生理作用は n-6 系脂肪酸と競合するだけでなく独自の作用をも持つため,独自の摂取基準を設定しました.

乳児

 0-5 ヶ月児の目安量は母乳中の n-3 系脂肪酸濃度 1.16 g/L に基準哺乳量 0.78 L/d を乗じて 0.9 g/d に設定しました.6-11 ヶ月児の目安量は 0-5 ヶ月児の目安量と平成 22 年および 23 年の国民健康・栄養調査に基づく 1-2 歳児の摂取量の中央値との平均値 0.8 g/d に設定しました.

小児・成人

 平成 22 年および 23 年の国民健康・栄養調査における n-3 系脂肪酸の総摂取量の中央値を目安量に設定しました.

妊婦・授乳婦

 平成 19 年から 23 年までの国民健康・栄養調査に基づく妊婦・授乳婦の n-3 系脂肪酸摂取量の中央値 1.8 g/d を目安量に設定しました.

α リノレン酸

 α リノレン酸と心血管疾患との間には弱い負の相関が報告されており,1 g/d のα リノレン酸摂取量の増加は心筋梗塞による脂肪を 10 % 減少させます.しかし日本人を対象とした十分な研究がないため,目標量は設定しませんでした.その他,前立腺がんのリスク,卵子機能との負の関連および妊娠可能性の低下の可能性など指摘されていますがいずれも確定したものではなく,α リノレン酸多量摂取の長期間の影響は分かっていません.

EPA および DHA

 EPA および DHA と冠動脈疾患との関連についてのメタ解析の結果は一致していません.日本人を対象とした研究には JPHC, JACC 研究JELIS などがあります.日本人における脳卒中への介入試験には JELIS があり,一次予防効果はなく二次予防効果のみ認められています.乳がんコホート研究のメタ解析結腸直腸がんコホート研究のメタ解析でのリスク減少の報告があります.日本人では JPHC 研究において近位大腸がんのリスク減少および肝がん罹患の減少が報告されています.認知症やうつ病については n-3 系脂肪酸との関連は分かっていません.

 魚には水銀,カドミウム,鉛やスズなどの重金属,PCB やダイオキシンなどの有害物質も含まれ,これらの有害物質については別の基準があります.そのため食事摂取基準では有害物質については考慮していません.

 n-3 系脂肪酸のうち α リノレン酸については 2010 年版では目標量が設定されていましたが 2015 年版では目標量は設定されていません.また EPA および DHA については 2010 年版では 18 歳以上において 1g/d 以上の摂取を推奨していましたが,2015 年版では目標量は設定されていません.

 n-3 系脂肪酸の食事摂取基準の 2015 年版および 2010 年版は下表のとおりです.

n-3 系脂肪酸の食事摂取基準 (g/d) (2015 年版)
性別 男性 女性
年齢 目安量 目安量
0-5 M 0.9 0.9
6-11 M 0.8 0.8
1-2 0.7 0.8
3-5 1.3 1.1
6-7 1.4 1.3
8-9 1.7 1.5
10-11 1.7 1.4
12-14 2.1 1.8
15-17 2.3 1.7
18-29 2.0 1.6
30-49 2.1 1.6
50-69 2.4 2.0
70- 2.2 1.9
妊婦 1.8
授乳婦 1.8
n-3 系脂肪酸の食事摂取基準 (2010 年版)
性別 男性 女性
年齢 目安量 (g/d) 目標量 (% energy) 目安量 (g/d) 目標量 (% energy)
0-5 M 0.9 0.9
6-11 M 0.9 0.9
1-2 0.9 0.9
3-5 1.2 1.2
6-7 1.6 1.3
8-9 1.7 1.5
10-11 1.8 1.7
12-14 2.1 2.1
15-17 2.5 2.1
18-29 ≤ 2.1 ≤ 1.8
30-49 ≤ 2.2 ≤ 1.8
50-69 ≤ 2.4 ≤ 2.1
70- ≤ 2.2 ≤ 1.8
妊婦 1.9
授乳婦 1.7

参照:
日本人の食事摂取基準(2015 年版)脂質 (pdf)
日本人の食事摂取基準(2010 年版)脂質 (pdf)

n-6 Fatty Acids

98% of the n-6 fatty acids that Japanese intake is linoleic acid. The organism can not synthesize n-6 fatty acids. Therefore, they must orally intake them. According to the National Health and Nutrition Survey in 2010 and 2011, the median of the n-6 fatty acids intake of Japanese were 10.0 g/d (4.3 %E) in male and 8.4 g/d (4.6 %E) in female, respectively. There are no reports required to set the Estimated Average Requirement for healthy people or no reports of dermatitis due to lack of n-6 fatty acids in usual diet, the approximate amount has been set.

Infant

The approximate amount for 0-5 months infant has been set to 4.0 g/d by multiplying the standard mammalian amount 0.78 L/d to n-6 fatty acids concentration of breast milk 5.16 g/L. The approximate amount for 6-11 months infant has been set to 4.3 g/d by calculating the average of the approximate amount of 0-5 months infant and of 1-2 years old child.

Adults and Child

The approximate amount has been set to the median of n-6 fatty acids intake based on the National Health and Nutrition Survey in 2010 and 2011.

Pregnant and Lactation

The approximate amount for pregnant has been set to 9 g/d based on the median n-6 fatty acids intake in pregnant in the National Health and Nutrition Survey from 2007 to 2011. The approximate amount for lactation has also been set to 9 g/d based on the median n-6 fatty acids intake in lactation.

It is not fully understood of the risk of linoleic acid that it is ingested in large amounts because it is easily oxidized than such monounsaturated fatty acids as oleic acid. And it is concerned of the safety of high intakes of linoleic acid because linoleic acid generate such inflammation including substance as prostaglandins and leukotrienes. Although the risk of overdose has been assumed for n-6 fatty acids, the approximate amount has not been set because there are no reports for Japanese subject.

The Dietary Reference Intakes of n-6 fatty acids in 2015 edition and 2010 edition are following table.

The Dietary reference Intakes of n-6 fatty acids (g/d) (2015 edition)
Gender Male Female
Age Approximate amount Approximate amount
0-5 M 4 4
6-11 M 4 4
1-2 5 5
3-5 7 6
6-7 7 7
8-9 9 7
10-11 9 8
12-14 12 10
15-17 13 10
18-29 11 8
30-49 10 8
50-69 10 8
70- 8 7
Pregnant 9
Lactation 9
The Dietary Reference Intakes of n-6 fatty acids (2010 edition)
Gender Male Female
Age Approximate (g/d) Target (% energy) Approximate (g/d) Target (% energy)
0-5 M 4 4
6-11 M 5 5
1-2 5 5
3-5 7 6
6-7 8 7
8-9 9 8
10-11 10 9
12-14 11 10
15-17 13 11
18-29 11 < 10 9 < 10
30-49 10 < 10 9 < 10
50-69 10 < 10 8 < 10
70- 8 < 10 7 < 10
Addition for Pregnant + 1
Addition for Lactation + 0

References:
The Dietary reference Intakes for Japanese (2015 edition) Lipid (pdf)
THe Dietary reference Intakes for Japanese (2010 edition) Lipid (pdf)

Lipid

The Dietary Reference Intakes have been set in lipids, saturated fatty acids, n-6 fatty acids and n-3 fatty acids. They have not been set in monounsaturated fatty acids, trans fatty acids, conjugated linoleic acid, diacylglycerol, medium chain triacylglycerol, plant sterols and cholesterol.

Especially, the Dietary Reference Intakes had been set for cholesterol in 2010 edition, such as 750 mg/d in male and 600 mg/d in female, they have been deleted in 2015 edition.

Lipid (fat energy ratio)

The Dietary Reference Intakes of lipid in 2015 edition and 2010 edition, the ratio of lipid in total energy (fat energy ratio), are following tables. The target amount in age group of grater than 30 years old has been revised. The Dietary Reference Intakes for pregnant and lactation have not been set.

The Dietary Reference Intakes of Lipid (% energy) (2015 edition)
Gender Male Female
Age Approximate amount Target amount (Median) Approximate amount Target amount (Median)
0-5 M 50 50
6-11 M 40 40
1-2 20-30 (25) 20-30 (25)
3-5 20-30 (25) 20-30 (25)
6-7 20-30 (25) 20-30 (25)
8-9 20-30 (25) 20-30 (25)
10-11 20-30 (25) 20-30 (25)
12-14 20-30 (25) 20-30 (25)
15-17 20-30 (25) 20-30 (25)
18-29 20-30 (25) 20-30 (25)
30-49 20-30 (25) 20-30 (25)
50-69 20-30 (25) 20-30 (25)
70- 20-30 (25) 20-30 (25)
Pregnant
Lactation
The Dietary Reference Intakes of Lipid (% energy) (2010 edition)
Gender Male Female
Age Approximate amount Target amount (Median) Approximate amount Target amount (Median)
0-5 M 50 50
6-11 M 40 40
1-2 20-30 20-30
3-5 20-30 20-30
6-7 20-30 20-30
8-9 20-30 20-30
10-11 20-30 20-30
12-14 20-30 20-30
15-17 20-30 20-30
18-29 20-30 20-30
30-49 20-25 20-25
50-69 20-25 20-25
70- 20-25 20-25
Pregnant
Lactation

References:
The Dietary reference Intakes for Japanese (2015 edition) Lipid (pdf)
THe Dietary reference Intakes for Japanese (2010 edition) Lipid (pdf)

脂質

 栄養学的に重要な脂質は脂肪酸,中性脂肪,リン脂質,糖脂質およびステロール類です.脂肪酸には二重結合を含まない飽和脂肪酸,二重結合が一つ存在する一価不飽和脂肪酸,二つ以上存在する多価不飽和脂肪酸があります.多価不飽和脂肪酸は二重結合の位置により n-3 系脂肪酸と n-6 系脂肪酸とに区別されます.不飽和脂肪酸には光学異性体があり,自然界にはシス型が大部分ですが,工業的に合成されるトランス型もあります.中性脂肪にはモノアシルグリセロール,ジアシルグリセロール,トリアシルグリセロールがあります.コレステロールはステロイド骨格を持ち炭化水素側鎖を持つ分子で,水にも油脂にも溶ける両親和性です.

 脂質は細胞膜の主要な成分でエネルギー産生の基質です.脂肪酸のエネルギー価は 9 kcal/g と炭水化物やたんぱく質の 2 倍以上です.また脂質は脂溶性ビタミン吸収を助けます.コレステロールは細胞膜の構成成分であり,肝臓で胆汁酸に変換されます.また性ホルモンや副腎皮質ホルモンなどのステロイドホルモン,ビタミン D の前駆体です.

 食事摂取基準が設定されたのは脂質,飽和脂肪酸,n-6 系脂肪酸,n-3 系脂肪酸のみです.一価不飽和脂肪酸やトランス脂肪酸,共役リノール酸,ジアシルグリセロールや中鎖トリアシルグリセロール,植物ステロール,コレステロールについては食事摂取基準は設定されていません.

 特にコレステロールについては 2010 年版では 18 歳以上の男性で 750 mg/d 未満,18 歳以上の女性で 600 mg/d 未満と食事摂取基準が設定されていましたが,2015 年版では撤廃されています.

脂質(脂肪エネルギー比率)

 2015 年版および 2010 年版における脂質の食事摂取基準,つまり脂質の総エネルギーに占める割合(脂質エネルギー比率)は下表のとおりです.2015 年版では 30 歳以上の目標量に変更がみられます.妊婦および授乳婦については摂取基準は設定されていません.

 0-5 ヶ月児の場合,母乳中の脂肪濃度は 3.5 g/100 g であり母乳 100 g 中の脂質由来のエネルギーは 31.5 kcal/100 g です.母乳 100g の総エネルギーは 65 kcal なので脂肪エネルギー比率は 48.46 % となり丸めて 50 %E と設定しました.6-11 ヶ月児の場合は 0-5 ヶ月児の目安量と 1-2 歳児の摂取量の中央値の平均値 37.9 %E に設定しました.1-2 歳児の摂取量は平成 22 年,23 年の国民健康・栄養調査に基づいています.

 小児および成人の脂質の目標量の下限値については,本文中に記載はありませんが,国民健康・栄養調査に基づいて 20 %E に設定されたようです.また欧米で低脂質とされるエネルギー比 30 %E 未満を目標量の上限値に設定したようです.

脂質の食事摂取基準 (% energy) (2015 年版)
性別 男性 女性
年齢 目安量 目標量(中央値) 目安量 目標量(中央値)
0-5 M 50 50
6-11 M 40 40
1-2 20-30 (25) 20-30 (25)
3-5 20-30 (25) 20-30 (25)
6-7 20-30 (25) 20-30 (25)
8-9 20-30 (25) 20-30 (25)
10-11 20-30 (25) 20-30 (25)
12-14 20-30 (25) 20-30 (25)
15-17 20-30 (25) 20-30 (25)
18-29 20-30 (25) 20-30 (25)
30-49 20-30 (25) 20-30 (25)
50-69 20-30 (25) 20-30 (25)
70- 20-30 (25) 20-30 (25)
妊婦
授乳婦
脂質の食事摂取基準 (% energy) (2010 年版)
性別 男性 女性
年齢 目安量 目標量(範囲) 目安量 目標量(範囲)
0-5 M 50 50
6-11 M 40 40
1-2 20-30 20-30
3-5 20-30 20-30
6-7 20-30 20-30
8-9 20-30 20-30
10-11 20-30 20-30
12-14 20-30 20-30
15-17 20-30 20-30
18-29 20-30 20-30
30-49 20-25 20-25
50-69 20-25 20-25
70- 20-25 20-25
妊婦
授乳婦

参照:
日本人の食事摂取基準(2015 年版)脂質 (pdf)
日本人の食事摂取基準(2010 年版)脂質 (pdf)