In the previous article, we discussed how fertility outcome can be improved through dietary intervention. While this is true, there are some dietary components that can negatively affect fertility, and hence, should be avoided, which are:
在上一篇文章中，我们聊到了如何通过调整饮食来帮助提高生育力。虽然良好的饮食确实有助于受孕，但也有一些食物成分可能对生育造成不良影响，因此最好尽量避免，主要包括以下几种：
- Refined sugars and carbohydrates
精制糖份和碳水化合物
Refined sugars and refined carbohydrates can negatively affect fertility. In women, excess consumption can lead to high blood sugar, which leads to an increase in insulin secretion. In the long term, this can cause insulin resistance, associated with higher androgen production, leading to impaired fertility. In men, high intake can cause high blood sugar and oxidative stress, which affects sperm quality and motility, and hormone production. Examples of refined sugar include table sugar, condensed milk, honey, and maple syrup. Refined carbohydrates include white rice, white bread, white flour and pastries.
精制糖和精制碳水化合物可能对生育力产生负面影响。
对女性来说，摄入过多这类食物会导致血糖升高，从而引发胰岛素大量分泌。长期下来，可能造成胰岛素阻抗，进而刺激体内雄激素（男性激素）水平升高，影响排卵和生育能力。
对男性而言，高糖饮食同样会引起血糖升高和氧化压力，影响精子的质量与活力，还可能干扰体内激素的正常分泌。
常见的精制糖包括：白砂糖、炼乳、蜂蜜、枫糖浆等。
常见的精制碳水化合物有：白米饭、白面包、白面粉制品和甜点等。
- Saturated fats (SFA)
饱和脂肪（SFA）
Fatty acids are the basis of all cell membranes. In males, SFA can change the structure of the sperm membrane, leading to poor motility and production. Research also finds that SFA can cause lower energy utilization of the sperm cell and increase oxidative stress, affecting fertility. Meanwhile, in females, SFA is associated with insulin resistance, increased inflammation and reduced function of a receptor responsible for metabolism, inflammation and cellular process (PPAR- γ), leading to poor fertility. SFA sources include processed meat, red meat, poultry skin, butter, lard, desserts like cakes and cookies, and fast food.
脂肪酸是所有细胞膜的基本组成成分。
对男性而言，摄入过多饱和脂肪酸（SFA）可能会改变精子膜的结构，导致精子活动力下降及数量减少。研究也发现，SFA会降低精子的能量利用效率，并增加氧化压力，从而影响生育力。
对女性来说，过量摄取SFA可能会造成胰岛素阻抗、体内发炎反应增加，并降低负责代谢与细胞功能的受体（PPAR-γ）的活性，进而影响受孕能力。
常见的SFA来源包括加工肉类、红肉、鸡皮、黄油、猪油、蛋糕、饼干及速食等。
- Trans fats (TFA)
反式脂肪（TFA）
Like SFA, in men, TFA can change the composition of the sperm membrane, causing deleterious effects on sperm motility, fluidity and density. TFA is also found to lower the probability of fertilization and is correlated with lower testosterone level and sperm count, all of which can negatively affect fertility. In women, TFA increases inflammation and is related to lower levels of DHA and EPA, leading to ovulatory infertility. TFA can be found in hydrogenated fat such as hard margarine, junk food, pastries, fast food, fried food et cetera.
与饱和脂肪酸（SFA）类似，反式脂肪酸（TFA）在男性体内可改变精子膜的组成，进而对精子的运动能力、流动性及密度产生不利影响。研究表明，反式脂肪酸不仅降低受精率，还与睾酮（testosterone）水平及精子数量的下降密切相关，均可能对男性生育能力造成负面影响。
女性体内摄入反式脂肪酸则会促进炎症反应，并与二十二碳六烯酸（DHA）及二十碳五烯酸（EPA）水平的降低相关，导致排卵性不孕。
反式脂肪酸主要存在于氢化脂肪制品中，如硬化人造黄油、垃圾食品、糕点、快餐及油炸食品等。
- Alcohol
酒精
Excessive and prolonged alcohol intake may alter ovulation and regulation of the menstrual cycle, as it can cause an increase in hormones such as testosterone and oestradiol in women. This can induce fertility issue. Consumption can also lead to toxicity to the foetus for pregnant women. Alcohol can also bring about fertility problems for men as it is associated with decreased testosterone, withering testicles and reduced sperm production. Alcohol abuse and intoxication is also related to sexual dysfunction such as arousal, erectile and ejaculatory dysfunction.
过量且长期饮酒会影响女性的排卵及月经周期的调节，因为酒精可能导致体内睾酮（testosterone）和雌二醇等荷尔蒙（oestradiol）水平升高，从而引发生育问题。对于怀孕女性，饮酒还可能对胎儿造成毒性，增加流产或胎儿发育异常的风险。
在男性方面，酒精摄入与睾酮水平下降、睾丸萎缩及精子生成减少有关，都会对生育力造成不良影响。长期酗酒或酒精中毒也常导致性功能障碍，如性欲减退、勃起困难及射精障碍等。
- Caffeine
咖啡因
Caffeine can be found in various products such as coffee, tea, energy drinks, carbonated drinks. Caffeine intake of more than 300mg/day can influence hormone levels in non-pregnant females due to interaction in the metabolic pathways, leading to reduced fertility. It can also affect hormone levels in pregnant women, possibly causing an unfavourable pregnancy outcome. In males, caffeine might cause changes in DNA of the sperm cells, which can contribute to infertility due to abnormal sperm production. Therefore, caffeine intake should be limited to 200 mg/day, or about 2 cups of coffee a day. Caffeine sources include coffee, tea, cocoa products, energy drinks and carbonated drinks. Energy and carbonated drinks should preferably be avoided altogether.
咖啡因存在于多种饮品和食品中，如咖啡、茶、能量饮料及碳酸饮料等。
对于非怀孕女性来说，每日摄入超过300毫克的咖啡因，可能会因干扰体内代谢途径而影响荷尔蒙水平，进而降低生育能力。对孕妇而言，咖啡因还可能影响孕妇体内的激素水平，进而引发不良妊娠结果。
在男性方面，过量咖啡因摄取可能导致精子DNA发生变化，造成精子生成异常，从而影响生育力。
因此，建议每日咖啡因摄取量应限制在200毫克以内（约相当于两杯咖啡）。咖啡因的常见来源包括咖啡、茶、可可制品、能量饮料及碳酸饮料。其中，能量饮料和碳酸饮料最好尽量避免饮用。
- Fishes with high mercury levels
高汞含量的鱼类
While fish consumption is recommended due to its high omega-3 content, which is important for fertility, some fishes with high mercury levels should be avoided. This is as mercury exposure can cause hormonal changes in men and can damage the sperm DNA, leading to impaired sperm motility and structure. Mercury can also cause menstrual and hormonal dysfunction in women, resulting in reduced fertility outcome. High mercury fishes are typically fishes that consume other fishes (also known as predator or carnivorous fish), large and have a long lifespan due to accumulation of mercury content. This includes king mackerel, marlin, shark, swordfish, bigeye tuna, bluefin, tilefish, ray, and orange roughy.
虽然鱼类富含对生育非常重要的Omega-3脂肪酸，适量食用有益健康，但某些含汞量较高的鱼类应尽量避免。汞暴露可能导致男性体内激素变化，损伤精子DNA，进而影响精子的活动力和结构。对女性来说，汞也可能引起月经和激素功能紊乱，降低生育能力。
含汞量高的鱼类通常是以其他鱼类为食的大型掠食性鱼类，寿命较长，因此体内容易积累汞。常见的高汞鱼类包括王鲭鱼、旗鱼、鲨鱼、剑鱼、大眼金枪鱼、蓝鳍金枪鱼、瓷鱼、鳐鱼和橙粗鳍鱼。
建议选择低汞的鱼类，如鲑鱼、鳕鱼、沙丁鱼等，适量食用以保障健康和生育能力。
- Excessive exercise
过度运动
Regular physical activity is important in improving fertility. However, excessive exercise should be avoided. This is as it can lead to hormonal imbalance, which can negatively impact sperm quality and ovulation, affecting fertility. Symptoms of over-exercising are reduced performance, fatigue, feeling depressed or anxious, mood swings, sleeping problems, overuse injuries, and unintended weight loss.
规律的体育锻炼对提升生育能力具有重要作用，然而应避免过度运动。过度运动可能导致激素失衡，进而对精子质量和排卵产生不利影响，影响生育能力。过度运动的症状包括运动表现下降、疲劳、情绪低落或焦虑、情绪波动、睡眠障碍、过度运动导致的损伤以及非故意的体重减轻。
References:
资料来源：
Su X et al 2025, Cristodoro M et al 2024, Baroutis D et al 2024, Łakoma K, Kukharuk O & Śliż D 2023, FDA US 2021, Henriques M G et al 2019, Bjørklund G et al 2019, Gaskins A J & Chavarro J E 2019, Çekici H & Akdevelioğlu Y 2018, Wise L A et al 2018, Salas-Huetos A, Bulló M & Salas-Salvadó J 2017, Heertum K V & Rossi B 2017, Ricci E et al 2017, Lyngsø J et al 2017, DOH Washington US ND.
