We all have certain levels of nutrition knowledge, from media, books, talks, etc. However, some of them can be very wrong and misleading, and subsequently can be life-threatening to some population groups. Let’s see what has been fooling us around, and kick it away with the clear science behind.
Q: “I’m diabetic, what can I eat when I’m feeling hungry in between meals and not worry about my blood sugar?”
Kath_Student Dietitian: For diabetes, we concern the most about how much carbohydrates you eat, because the carbohydrates act the quickest to elevate your blood glucose level. First of all, we need to know that carbohydrates exist in many foods, also in many commonly consumed snacks. For instance, biscuits, fruits, crisps, dairy, beans, some vegetables, etc. If you take diabetic medications, like Metformin, to increase your insulin sensitivities, your pancreas will act more sensitive to the additional carbohydrates from carbohydrate-containing snacks. You still need to monitor your BGLs after snacking. Some options are like a salad with healthy dressings (olive oil) and nut sprinkles, boiled eggs, tofu snacks, etc. These provide a minimal amount of carbohydrates. If you take insulin injections, make sure you have some carbohydrates, to avoid unintentional hypoglycaemia. Remember that the packagings of products usually list out the nutritional information (carbohydrate content is a compulsory item to identify) of the food items, and you can check how much carbohydrate something has before you eat it carefree. The best practice is to monitor your blood glucose levels regularly and adjust your dosage of medication or insulin.
[Pregnancy & Lactation]
Q: “I’m currently 6-month pregnant, and I read some blogs saying that alcohol is not prohibited during pregnancy, as wine has beneficial effects to health and drink in small amounts should be harmless. Is this right? How much can I drink on special occasions, then?”
Kath_Student Dietitian: That’s a great question, you know that a lot of pregnant ladies do not know if they should avoid drinking when they are dining out. As leading countries, their nutrition advisory committee would suggest all pregnant women do NOT consume any alcohol during the whole pregnancy journey. Alcohol can penetrate the placenta freely. Fetuses do not have fully developed organs to get rid of these toxic substances, and therefore can accumulate in the fetus for a longer time than how long it takes to metabolise alcohol by the mother. No current clinical practice guideline outlines an upper limit for alcohol allowance is due to the ethical issues to conduct such a study on pregnant women. The safest practice is to NOT drink any alcohol, and I’m sure if you explain this to your friends on social events that you concern about the safety of your baby, they shall express their understandings. And you are right about the benefits of wine, you can always drink some before getting pregnant or after giving birth, because what the alcohol can do to you and your babies in the short-term and long-term is still not known for sure by the science.
Q: “I used to drink milk for bone health, but now milk is making me sick. What can I have for calcium instead? I’m worried about my bones.”
Kath_Student Dietitian: Milk contains a significant amount of lactose. As we grow into our later life stages, our ability to digest lactose is fading, with reducing available enzymes for it. If we do not fully digest all the lactose in one glass of milk we drink, the undigested lactose would be further fermented and produce gas in our gut. Therefore, if you feel bloated or even pain in your abdomen, it can suggest that you are not tolerating lactose as you used to be. Some potential solutions are either reducing the amount of milk you drink at a time, or going for alternatives with less lactose content. Yoghurt is a good option, where the lactose is being partially digested during its fermentation process. Yoghurt has a similar quantity of calcium as milk, as it is a fermented version of milk products. The fermentation processes the lactose, not the calcium. If you find yourself tolerating no lactose, there are goat’s milk or lactose-free cow’s milk available around the market. Also, you can consider plant-based milk, like soy milk, rice milk, almond milk, oat milk, etc. These are naturally lactose-free, and are definitely safe for lactose intolerant individuals. If you worry about calcium, these plant-based milks are naturally low in calcium content, there are commercially available plant-based milks have calcium added, if in doubt, check the nutritional information panel available on the packagings.
Q: “My blood test revealed a high cholesterol. Can I still have egg yolk or stir-fried dishes with it?”
Kath_Student Dietitian: High blood cholesterol levels have two main contributing factors, externally from diet or internally from self-production of cholesterol. Firstly, you can have a look at your diet, are you consuming high-cholesterol foods throughout the day and especially your favourite dishes. Secondly, the dinner you had the night before you had the blood test, was it a big meal with lots of high-fat foods? The majority of your blood cholesterol is made inside you. Thus, the medication for reducing cholesterol, the statin, works in a mechanism where it interferes with the cholesterol production process inside your body. The egg yolk has 250-300 mg of cholesterol, and we only need 200-300 mg of dietary cholesterol per day. Therefore egg yolks are recognised as a high-cholesterol food. Despite cholesterol, egg yolks contain fat-soluble vitamins and lecithin. The latter is heavily promoted as a nutritional supplementary product seen in many health stores. Also, the egg yolk is protective to your eyes, the yellower the yolk is, the more benefits it has to eyes. Do not be afraid of cholesterol, every one of us needs it, for all our cells. What you can do with egg yolks, try to have it in moderation and less frequently, maybe three days a week instead of eating it every day. And re-test your blood cholesterol once every while, as suggested by your doctors.
Q: “I suffer from constipation, I can only rely on laxatives, is there any concerns if I continue using laxatives?”
Kath_Student Dietitian: Laxatives do help resolve constipation, however long-term use of them can bring some harm to your internal and external anal sphincter. That sphincter is responsible for evacuation by contraction or relaxation to allow the passage of faeces. With the laxative abuse, the rectal sphincter may lose elasticity and fail to control the opening and closure for complete and healthy evacuation of faeces. Once the integrity of the sphincter is compromised, it is hard to recover it, even with a cessation of laxatives. Thus, laxatives are not suggested as a proper solution for chronic constipation, it may be used for short-term. You can try some herbal tea, probiotics, apples, sesame seeds or even coffee (caffeine can well stimulate bowel motility). In your diet, you can increase your dietary fibre (especially soluble fibre) and water intakes, to facilitate with an easier bowel movement. More importantly, see your doctor to understand the underlying clinical reasons for your chronic constipation and get it managed.
[Questions & Doubts]
Dear followers, all of your helpful questions are welcomed because your questions do not only bother you, but a lot of others out there. So ask away, and you may help your friends! Any private or confidential questions, I’ll keep it private and reply to you ASAP. Cheers!
作者 Kath_S Dietitian：对于糖尿病，我们最关心你吃多少碳水化合物，因为碳水化合物是能够最快升高你的血糖值。首先，我们必须明白，碳水化合物是存在于许多食物和常见的小零食，例如，饼干、水果、薯片、乳制品、豆类、一些蔬菜等。如果你服用糖尿病药物，如二甲双胍，来提高胰岛素的敏感性，你的胰腺将对额外摄取的碳水化合物及时处理，以维持正常血糖水平。安全起见，你还需要在加餐之后，定时测量你的血糖。你可以尝试在加餐的时候，给自己准备一份蔬菜沙拉，撒上橄榄油和坚果碎、或者煮上一个鸡蛋、或者是豆腐类的健康小零食，这些仅含有少量的碳水化合物，更利于控制你的血糖。如果你注射胰岛素，那你必须摄取含有碳水化合物的加餐，以避免无意识导致的低血糖。还要记住，产品的包装纸上通常会列出的食物的营养信息（碳水化合物的含量是一个必列项目），你可以查看每个食物有多少碳水化合物，再选择你要吃什么，那就可以吃得放心啦。最佳策略就是要定期监测您的血糖水平，并调整药物或胰岛素的剂量。
作者 Kath_S Dietitian：这是一个很好的问题，你知道很多孕妇在外出就餐时，并不知道他们应该避免喝酒。发展国家的营养咨询委员均建议所有孕妇在整个怀孕期间不摄取任何酒精。酒精可以自由进入胎盘，而胎儿还没有发育完全的器官，以分解这些有毒物质，因此酒精停留在胎儿体内的时间久过母亲体内分解酒精。由于对怀孕妇女进行此类研究的伦理限制，目前没有任何临床实践指南能够明确得列出酒精摄取的上限额度。最安全的做法是不喝任何酒精，我相信如果在社交场合，向劝酒的朋友解释你对胎儿安全的担忧，应该是能得到理解的。你说的没错，葡萄酒的确有很多好处，记得在你怀孕前后你当然可以饮用，但是孕期饮酒对你自身和胎儿的短期和长期影响仍然不被科学所肯定。
作者 Kath_S Dietitian：牛奶含有大量的乳糖。随着我们年纪增大，我们消化乳糖的能力渐渐衰退，用来消化乳糖的消化酶也在减少。如果我们不能完全消化一杯牛奶中的乳糖，未消化的乳糖将在我们的肠道中发酵并产生气体。因此，如果你感到腹部胀气甚至疼痛，这就是证明也许你不能耐受如此大量的乳糖，即使你以前喝完一杯牛奶完全没事。如何来解决呢？你可以尝试减少一次性喝牛奶的量，或改喝含有较少乳糖的替代品。比如酸奶，牛奶中的乳糖在其发酵成酸奶的过程中被部分消化完毕。而且酸奶含有与牛奶相似的钙量，因为它只是液体奶的发酵版本。整个发酵过程只是处理了乳糖，并不影响其中的钙质。如果你知道自己不耐受乳糖，市场上还有销售山羊奶或无乳糖牛奶。此外，你还可以考虑植物奶，如豆奶、米奶、杏仁牛奶、燕麦牛奶等。这些都是天然无乳糖，对于乳糖不耐症的人群是绝对安全的。如果你担心补钙问题，这些植物奶本身钙含量是较牛奶低，但是很多市售的植物奶有人工添加钙质，如果不确定，记得检查包装上的营养信息哦。
作者 Kath_S Dietitian：高血胆固醇主要有两个因素，外在因素由饮食摄取，或内在因素由自身产的胆固醇。首先，你可以检查你的饮食，你是不是摄取了过多的高胆固醇食物，特别是那几道你最喜欢的菜，它们是高胆固醇的吗？其次，在你验血的前一天晚上，你是不是吃了一顿大餐，包括了很多高脂肪食物？你大部分的胆固醇都是由你自身产生的。因此，用于降低胆固醇的药物，他汀类药物的作用机制就是干扰您体内的胆固醇产生过程。每颗蛋黄有250-300毫克的胆固醇，而我们每天只需要200-300毫克的膳食胆固醇。因此，蛋黄被认为是高胆固醇食物。除了胆固醇，蛋黄还含有脂溶性维生素和卵磷脂。后者被大量推广为营养保健品。此外，蛋黄还能保护你的眼睛，蛋黄的颜色越黄，有利于眼睛保健的物质更多。其实，不要害怕胆固醇，因为我们每个人的每一个细胞都需要它。你可以适量的摄取蛋黄或者减少吃蛋黄的频率，由每天吃改为每周吃三天。并根据医生的建议，定期复查你的血胆固醇。
作者 Kath_S Dietitian：泻药的确有助于解决便秘，但长期使用可能会对你的直肠括约肌带来伤害。这括约肌是负责通过收缩或松弛来辅助和允许排泄的过程。如果滥用泻药，直肠括约肌可能会失去原有的弹性，无法自由控制收缩和松弛，也不能很好的完成排泄的过程。一旦括约肌的完整性受损，即使在停用泻药的情况下也很难恢复。因此，泻药是不被采取用来解决慢性便秘的，它只可以短期使用。你可以试试看一些凉茶、益生菌、苹果、芝麻，甚至咖啡（咖啡因可以很好地刺激肠蠕动）。你也可以增加你的膳食纤维（特别是可溶性纤维）和水摄入量，便于肠道蠕动。 更重要的是，请您的医生检查并诊断你慢性便秘的潜在临床原因，并得到适当的医学管理。