Nutrition and Aging: What to Eat for a Long and Healthy Life? 怎樣吃才可以促進健康長壽？

Nine hallmarks of aging

1. Genomic instability
2. Telomere attrition, otherwise known as “telomere shortening”
3. Epigenetic alterations, such as altered methylation
4. Loss of proteostasis
5. Deregulated nutrient sensing
6. Mitochondrial dysfunction
7. Cellular senescence
8. Stem cell exhaustion
9. Altered intercellular communication

衰老的九個重大指標:

1. 基因組不穩定
2. 端粒損耗，也稱為端粒縮短
3. 表觀遺傳改變，例如甲基化改變
4. 蛋白穩態降低
5. 營養素感應失控
6. 線粒體功能障礙
7. 細胞衰老
8. 幹細胞衰竭
9. 細胞間通訊不良

(想進一步閱讀上面九個重點的朋友可以點進去英文原版，用Google翻譯閱讀)

Inflammaging: A Cause and Effect of Aging

While not included on the list of nine hallmarks of aging, the phenomenon of “inflammaging” is also a central component of the aging process. Inflammaging (inflammation + aging) refers to the chronic, low-level inflammation characteristic of aging. Inflammaging sits at the confluence of multiple hallmarks of aging, linking cellular senescence with deregulated nutrient sensing and other age-related pathologies. Adverse changes in the gut microbiota may also contribute to inflammaging, suggesting that the gut microbiota may be an essential target for interventions designed to support healthy aging.

體內發炎是生理老化的原因也是後果

儘管沒有列入老化的九個標誌，但發炎現像也是老化過程的重要一環。 發炎 (inflammaging = “inflammation/aging”, 發炎+衰老) 是人體衰老過程中一種緩慢、長期、低度的發炎特徵。從病理學上來看，發炎位於上面列舉的九大衰老指標的交匯處，將細胞衰老與失調的養分感應和其他與年齡相關的病理現象串聯在一起。 不健康的腸道菌群變化也可能導致發炎，這也表示健康的腸道菌群可能是延緩衰老的重要指標。

Six Steps to Achieving Optimal Nutrition for Healthy Aging

1. Say “Goodbye” to the Standard American Diet
2. Eat a Nutrient-Dense, Anti-Inflammatory Paleo-Template Diet
3. Support Your Microbiome
4. Improve Blood Sugar Stability
5. Try Fasting and Time-Restricted Feeding
6. Consider a Ketogenic Diet

實現緩老化最佳飲食的六個步驟：

1. 對所謂的”美國標準飲食”說再見 (小編註：台灣、大陸、和東南亞大眾的飲食跟美國標準飲食非常類似)
2. 多吃高營養、抗發炎的遠古人類飲食 (Paleo Diet)
3. 多吃可以改善腸道菌群的飲食
4. 提高血糖穩定性(盡量少吃會快速讓血糖飆高的食物）
5. 嘗試斷食和限時進食
6. 考慮採行生酮飲食

How Dietary Protein and Glycine Impact Aging

Dietary protein is a contentious topic in discussions of both overall health and anti-aging and longevity. Several prominent scientists in the field of aging and longevity recommend avoiding or limiting animal protein and keeping overall protein intake low. I don’t agree with these recommendations for several reasons.

膳食蛋白質和甘氨酸如何影響衰老

飲食蛋白不管在整體健康或抗衰老領域裡都是一個高度爭議性議題。衰老和長壽領域裡有幾位傑出科學家建議避免或限制動物蛋白質，並保持蛋白質的總體攝入量低。但我不同意這些建議，等我在下面做說明。

First of all, the anti-protein and anti-animal protein sentiment in the aging space originates with a relatively one-dimensional observation, that animal protein increases IGF-1 (Insulin-like growth factor 1). As I mentioned before, IGF-1 has been inconsistently linked with accelerated aging. However, what some researchers and low-protein diet advocates fail to say is that carbs also increase IGF-1.

首先，在衰老的研究領域裡，反對攝取蛋白質或動物性蛋白質的看法，是來自一個有偏狹隘的觀點：即動物蛋白質會增加IGF-1 (Insulin-like growth factor 1, 胰島素樣生長因子1, 也被稱為生長調節素C)。但正如我之前在其他文章裡提到的，IGF-1與加速衰老的關聯性目前還是偏弱。另外，這些提倡低蛋白飲食可以幫助抗老化的研究人員卻沒有指出其實碳水化合物也會增加IGF-1。

Secondly, while amino acids from protein do activate mTOR (mammalian Target of Rapamycin), this isn’t always a bad thing! We need mTOR activation to build and maintain muscle mass, which is a crucial determinant of healthy aging. However, we don’t want mTOR activated all the time. This is where interventions such as fasting and periodic protein restriction, such as with the FMD, can come in handy because they downregulate mTOR and activate AMPK.

其次，儘管蛋白質中的氨基酸會激活mTOR (mammalian target of rapamycin, 哺乳動物雷帕黴素靶點，屬於一個重要的真核細胞信號，協調細胞生長、代謝，影響轉錄和蛋白質合成，調節細胞的凋亡、自噬等)，但這並不一定是一件壞事！我們必須靠激活mTOR來建立和維持肌肉質量，這是健康的衰老過程裡的一個關鍵因素。只是，長期過度激活mTOR對健康就會有害。所以，像斷食和定期限制蛋白質的攝取（例如FMD, Fasting Mimic Diet）之類的飲食措施可以派上用場，因為會有下調mTOR並激活AMPK的效果。

Glycine and Methionine Balance May Be Critical for Healthy Aging 甘氨酸和蛋氨酸的平衡可能對健康衰老至關重要

Finally, much of the research on animal protein and longevity has looked at one amino acid found in abundance in animal protein, methionine, in isolation. High-methionine diets are associated with worse health outcomes in aging whereas, in preclinical models, methionine restriction is associated with longevity.

最後，有關動物蛋白和壽命的許多研究都只單獨針對一種在動物蛋白中發現的氨基酸 – 蛋氨酸(Methionine)。高蛋氨酸飲食與衰老時健康狀況惡化有關聯性，而在臨床前模型中，限制蛋氨酸與長壽有關聯性。

When we take a cue from ancestral diets and balance our methionine intake with adequate glycine, an amino acid found in collagenous cuts of meat and bone broth, we may neutralize the possible detrimental effects of methionine excess on aging. In preclinical research, supplementation with glycine has been found to alleviate adverse changes in gene expression related to aging and extends lifespan to the same degree as methionine restriction. This occurs because glycine is a one-carbon donor that supports the methylation cycle by promoting the formation of the universal methyl donor S-adenosyl methionine (SAMe) and thus playing an intrinsic role in methylation. Glycine also protects against oxidative stress and inflammation, which contribute to aging. 

然而，當我們從遠古祖先的飲食中去尋找線索，卻發現如果在蛋氨酸攝入的同時也攝取適量的甘氨酸(Glycine, 在多筋肉類和骨肉湯的膠原蛋白切片中特別多的一種氨基酸)，讓這兩種氨基酸之間取得平衡時，就會中和蛋氨酸過量對衰老可能造成有害影響。在臨床前研究中，已發現補充甘氨酸可緩解與衰老相關的基因表達的負面變化，與限制蛋氨酸有相同的壽命延長效果。之所以會有這種的變化，是因為甘氨酸是一種單碳供體，通過促進通用甲基供體S-腺苷甲硫氨酸（SAMe）的形成來支持甲基化循環，從而在甲基化中發揮了作用。甘氨酸還可以防止氧化應激和體內發炎，而氧化和炎症兩者都是導致衰老重要因素。

Glycine is also crucial for the synthesis of purines, which are essential components of DNA and necessary for DNA repair.

甘氨酸對於嘌呤的合成也至關重要，嘌呤是DNA的必需成分，也是DNA修復所必需的。

Remark by Coach Denys:

The above 6 paragraphs regarding protein intake explain why eating red meat does not necessarily speed up ageing or causing cancer. Only if majority of your protein intake is red meat has such risk. The amino acid strongly associated with mTOR activation, methionine, abounds in red meat. To mitigate the negative health effects caused by methionine, it is important to balance it with glycine, which is found in the tendon and tissues connecting red muscle tissues to the bones, and many other parts of the animal, including skin, ear, tail and many organ meat. This is why the notion of “eating an animal from nose to tail” is super important for optimal health. Haven’t you heard about the teaching that whole food is much more nutrient dense?

Coach Denys 補充說明：

上面關於蛋白質攝入的六段文字解釋了為什麼吃紅肉並不一定會加速衰老或導致癌症。只有當您攝入的大部分蛋白質都是紅肉時才有這種風險。 與mTOR活化密切相關的氨基酸蛋氨酸在紅肉中特別多。 為了減輕蛋氨酸對健康的負面影響，重要的是要另外多攝取甘氨酸來達到平衡。甘氨酸在動物的筋和韌帶(將紅色肌肉組織連接到骨骼的細胞組織)以及許多其他部位的組織中，包括皮膚，耳朵，尾巴和許多內臟組織裡特別多。 這就是為什麼“食用動物就該從頭吃到尾整隻吃掉”的是健康飲食裡很重要的一個原則。 “從頭吃到尾“就是大家熟悉的吃全食(whole food)的概念，不是嗎？

Nutraceuticals that May Help Slow Aging

Finally, specific nutraceutical compounds may also be useful for slowing the aging process and promoting longevity.

STACs (Sirtuin Activating Compounds) such as quercetin, pterostilbene, and resveratrol improve sirtuin function by lowering the Km (Michaelis constant) value for sirtuin enzymes：

• Resveratrol
• Berberine
• Curcumin
• Sulforaphane found in cruciferous vegetables

有助於延緩衰老的保健食品

最後，特定的保健食品化合物也可用於減緩衰老過程並提高壽命。諸如槲皮素，蝶形萜和白藜蘆醇之類的STACs (Sirtuin Activating Compounds) 會通過降低瑟土因酶的Km（Michaelis常數）值來改善瑟土因功能：

• 白藜蘆
• 黃連素
• 薑黃素
• 十字花科蔬菜中發現的蘿蔔硫素 (小編註：十字花科蔬菜包括花椰菜、紫甘藍、結球甘藍、羽衣甘藍、芥菜、雪裡紅、蘿蔔、油菜、塌棵菜。 )