What Your Diet Means For Your Hairline

呂思雨

We all know the dangers of a diet thats high in fat. From hypertension to diabetes， heart disease to even some forms of cancer， the range of ailments that can be laid squarely at the feet of eating poorly and being overweight or obese. But a new study from researchers at the Toyko Medical and Dental University （TMDU） in Japan have now found having a fat-heavy diet can also accelerate hair loss.

In the average healthy adult， the hair follicle stem cells（HFSCs） renew themselves regularly which is why your hair grows back when you cut it and also why it becomes longer. As with most things in the human body， though， the onset of age doesnt do the HSFCs any favours and， as you get older， the stem cells lose their ability to replenish as efficiently as they once did， leaving the hair to thin or fall out.

In the study carried out by TMDUs department of stem cell biology， mice that had been given a high-fat diet（HFD） were more susceptible to inflammatory responses in the body which， in turn， blocked follicle regeneration， leading to hair loss. What was surprising was that the deterioration in the hair follicles could happen in as little as four days spent on a high-fat diet and that the problem seemed to be worse in older mice.

“High-fat diet feeding accelerates hair thinning by depleting HFSCs， especially in old mice，”explains Hironobu Morinaga， the studys lead author.“We compared the gene expression in HFSCs between HFD-fed mice and standard diet-fed mice and traced the fate of those HFSCs after their activation.

Its not just the fat content of your food that can play havoc with your hair as what you consume can really affect how your hair grows and even whether men will keep it， as consultant dermatologist DrAliaAhmed explains.

Nutritional deficiencies are often the root cause of many hair problems， adds Dr Ahmed.“Iron， zinc， niacin， folic acid， biotin， vitamin A， vitamin D， vitamin E—there are so many nutrients implicated in hair disorders，”she says.“Its not just genetics.”

If youve got a sweet tooth， for example， you may need to think about putting down those Percy Pigs. Not only is sugar bad for your hair， but it can cause your blood sugar levels to spike which， in men， can raise the levels of the hormone androgen， leading to follicle damage and potential hair loss.

But dont make the mistake of swapping sugar for artificial sweeteners. Take diet fizzy drinks that replace processed sugar with artificial sweeteners like Aspartame， for instance. In their analysis of aspartame， the United States Food and Drug Administration （FDA） has listed hair thinning and hair loss as one of the main side effects of excessive aspartame consumption.

Drinking alcohol might not lead to hair loss in men（largely because it acts to suppress testosterone） but the condition of your locks will certainly be affected by one too many as it reduces your bodys ability to absorb key nutrients like folic acid and zinc， making your hair prone to damage like split ends and brittleness. Go easy on salt too. Its been shown to cause hair shedding as well.

我們都知道高脂肪飲食的危害。高血壓、糖尿病、心臟病，甚至一些癌癥都可以直接歸咎于飲食不健康或肥胖。但日本東京醫(yī)科齒科大學（TM？ DU）研究人員的一項新研究發(fā)現(xiàn)，高脂肪飲食也會加速脫發(fā)。

一般健康成年人的毛囊干細胞會定期自我更新，這就是為什么你剪掉的頭發(fā)會長回來，也是頭發(fā)會變長的原因。然而，與人體內的大多數情況一樣，年齡對毛囊干細胞沒有任何好處，隨著年齡的增長，干細胞失去了以前那樣的更新能力，導致頭發(fā)變少或脫發(fā)。

在東京醫(yī)科齒科大學干細胞生物學系開展的研究中，高脂飲食喂養(yǎng)的小鼠更容易受到體內炎癥反應的影響，而炎癥反應會阻礙毛囊再生，導致掉毛。令人驚訝的是，短短四天的高脂肪飲食就可讓毛囊發(fā)生退化，而老年鼠的問題似乎更嚴重。

該研究的主要作者Hironobu Morinaga解釋說：“高脂肪飲食喂養(yǎng)讓毛囊干細胞變少，特別是老年小鼠。我們比較了高脂肪飲食喂養(yǎng)的小鼠和標準飲食喂養(yǎng)的小鼠之間毛囊干細胞的基因表達，并追蹤了這些毛囊干細胞激活后的命運。

皮膚科顧問醫(yī)生艾莉亞·艾哈邁德博士解釋稱，不僅僅是食物中的脂肪含量會破壞你的頭發(fā)，吃的東西會影響頭發(fā)的生長，甚至影響男人能否保住頭發(fā)。

艾哈邁德博士補充說，營養(yǎng)缺乏往往是許多頭發(fā)問題的根本原因?！拌F、鋅、煙酸、葉酸、生物素、維生素A、維生素D、維生素E——頭發(fā)疾病涉及到太多營養(yǎng)素。不僅僅是遺傳因素?！?/p>

例如，如果你喜歡吃甜食，你可能需要考慮放棄那些橡皮糖。糖不僅對你的頭發(fā)有害，而且會導致血糖水平升高，而男性的血糖升高會導致雄激素水平升高，導致毛囊損傷和潛在的脫發(fā)。

但用人工甜味劑代替糖是錯誤的，不要這么做。以阿斯巴甜等人工甜味劑代替加工糖的低糖汽水為例，美國食品和藥物管理局（FDA）在對阿斯巴甜的分析中發(fā)現(xiàn)，頭發(fā)稀疏和脫發(fā)是阿斯巴甜攝入過量的主要副作用之一。

飲酒可能不會導致男性脫發(fā)（主要是因為酒精能抑制睪丸激素），但頭發(fā)肯定會受到很大影響，因為飲酒會降低人體吸收葉酸和鋅等關鍵營養(yǎng)素的能力，使頭發(fā)容易出現(xiàn)分叉和脆弱等損傷。鹽也要少吃。有研究表明，鹽也會導致脫發(fā)。