減鹽降壓 • 食得其法
1. 減鹽對心血管健康管理,包括高血壓,真的有幫助嗎?
- 鹽攝取量與心血管健康有密切關係1–3
- 來自全球不同研究團隊發現減低鹽攝取量有助降低血壓4,5
- 減低鹽攝取量亦能有效降低高血壓相關的併發症6,包括:
- 冠狀血管疾病(簡稱冠心病)7
- 心臟衰竭8
- 中風9
- 慢性腎病10
2. 坊間有人說減鹽,又有人說低鈉,究竟什麼是鹽,什麼是鈉?我們可以自行計算食物的鹽含量嗎?
- 食鹽是一種名為氯化鈉 (Sodium chloride) 的化合物,當中含有40% 鈉(Sodium)11
- 換言之,每1,000 毫克食鹽就含有400 毫克鈉
- 如果想知道食物中的鹽含量,只要將鈉含量乘以2.54便可計算出來12
- 例如:100克的薯條鈉含量為 652 毫克,即相等於652 x 2.54 = 1,656毫克鹽
3. 國際組織和臨床專家團隊對於高血壓患者的鹽攝取量有什麼建議?
- 無論是世界衛生組織,即世衛,抑或歐美的心臟學會專家均建議高血壓患者的日常飲食應減少攝取鹽,從而降低血壓和減少患上心血管疾病,如中風及冠心病,的風險13–15
- 根據世衞於 2012 年制定關於鈉/鹽攝取量的指引,無論是否患有高血壓,當中建議成年人每日應攝取少於 2,000 毫克鈉,即相等於大概 5,000 毫克食鹽13
- 同樣,歐洲心臟學會於2018年發表的高血壓治療指引亦建議高血壓患者每日鈉攝取量應少於2,000毫克14
- 美國心臟學院及美國心臟協會於2017年發表的最新高血壓指引,以減少鈉攝取量為一項非藥物介入治療,建議高血壓患者每日鈉攝取量應少於 1,500 毫克或每天減少 1,000 毫克鈉15
- 更有臨床研究證實,此幅度的鈉攝取量可減低高血壓患者的「收縮壓」或稱「上壓」5–6 mmHg16,17
4. 何謂高鹽/鈉飲食?高血壓患者應避免進食哪些食物?
- 大家要避免高鈉食物!
- 根據食物安全中心指引,每 100 克食物含有多於 600 毫克鈉,或每 100 毫升食物含有多於 300 毫克鈉,就屬於高鈉18
- 而每 100 克或 100 毫升食物含 120 毫克或以下的鈉,則可稱為低鈉18
- 值得一提的是,不同地區人群攝取鈉的主要膳食來源大有不同,有研究分析,中國人的主要鈉來源是從烹調時添加的鹽(75.8%)中攝取19
5. 那麼在烹調時不添加太多食鹽,是否就可以避免高鹽陷阱,食得更加健康?
- 除了食鹽以外,烹調時所加入的醬料也能夠增加我們的鈉攝取量
- 食物安全中心2012年公佈的調查結果顯示,香港人主要從佐料和醬料攝取鈉,例如蠔油、調味粉、沙律醬等,平均每100克醬料的鈉含量約 3,600 毫克,最高含量更超過16,000毫克,超出世衛指引的上限8倍20
- 同時,調查報告亦指出醃菜類,例如榨菜,梅菜等,鈉含量高達每100克8,700毫克,超出世衛指引上限4倍20
- 所以即使改掉「加鹽」這個習慣,還需要減少進食醃製食物,這樣才能食得更加健康!20
6. 每次提起要「少鹽」,很多人都會聯想到淡而無味的食物,這樣很難持之以恆啊!該如何在日常生活中控制鹽份的攝取而不失味道?
- 減少進食醃製食物,例如加工肉類、鹹蛋、鹹魚、醃菜、調味湯粉等21
- 選用新鮮材料(如用蕃茄、南瓜)製作醬汁,代替現成蕃茄醬、沙律醬21
- 使用香草和天然香料,如蒜頭、胡椒、檸檬汁等作為調味品,取代高鹽和高鈉的醬料21,22
- 以新鮮蔬果和不添加鹽的果仁作為零食21,22
- 外出用膳時作出“聰明選擇”,例如薄餅或三文治可選擇蔬菜(如蕃茄、青椒、蘑菇)作為配料,取代加工肉類(例如香腸、煙肉和火腿等)22,23
- 最後,可以參考印在包裝紙上的食物標籤,更清楚了解並比較不同食物的鈉含量,從而選擇鈉含量較低且符合個人偏好的食物21,24
References
- Gibbs CR, Lip GY, Beevers DG. Salt and cardiovascular disease: clinical and epidemiological evidence. J Cardiovasc Risk. 2000;7(1):9-13.
- Bochud M, Marques-Vidal P, Burnier M, Paccaud F. Dietary Salt Intake and Cardiovascular Disease: Summarizing the Evidence. Public Health Rev. 2011;33(2):530-552.
- He FJ, MacGregor GA. Salt reduction lowers cardiovascular risk: meta-analysis of outcome trials. Lancet. 2011;378(9789):380-382.
- Graudal NA, Hubeck-Graudal T, Jürgens G. Effects of low-sodium diet vs. high-sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride (Cochrane Review). Am J Hypertens. 2012;25(1):1-15.
- Sacks FM, Svetkey LP, Vollmer WM, et al. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. DASH-Sodium Collaborative Research Group. N Engl J Med. 2001;344(1):3-10.
- Ventura HO, Lavie CJ. Impact of comorbidities in hypertension. Current Opinion in Cardiology. 2016;31(4):374-375.
- Cappuccio FP. Cardiovascular and other effects of salt consumption. Kidney Int Suppl (2011). 2013;3(4):312-315.
- Colin-Ramirez E, McAlister FA, Zheng Y, Sharma S, Armstrong PW, Ezekowitz JA. The long-term effects of dietary sodium restriction on clinical outcomes in patients with heart failure. The SODIUM-HF (Study of Dietary Intervention Under 100 mmol in Heart Failure): a pilot study. Am Heart J. 2015;169(2):274-281.e1.
- Li Yun, Huang Zhe, Jin Cheng, et al. Longitudinal Change of Perceived Salt Intake and Stroke Risk in a Chinese Population. Stroke. 2018;49(6):1332-1339.
- McMahon EJ, Bauer JD, Hawley CM, et al. A randomized trial of dietary sodium restriction in CKD. J Am Soc Nephrol. 2013;24(12):2096-2103.
- Salt and Sodium | The Nutrition Source | Harvard T.H. Chan School of Public Health. Accessed March 12, 2021. https://www.hsph.harvard.edu/nutritionsource/salt-and-sodium/
- Okuda N, Nishi N, Ishikawa-Takata K, et al. Understanding of sodium content labeled on food packages by Japanese people. Hypertension Research. 2014;37(5):467-471.
- World Health Organization. Guideline: sodium intake for adults and children. Published 2012. Accessed March 12, 2021. https://www.who.int/publications/i/item/9789241504836
- Williams B, Mancia G, Spiering W, et al. 2018 ESC/ESH Guidelines for the management of arterial hypertension. Eur Heart J. 2018;39(33):3021-3104.
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2018;71(19):e127-e248.
- Aburto NJ, Ziolkovska A, Hooper L, Elliott P, Cappuccio FP, Meerpohl JJ. Effect of lower sodium intake on health: systematic review and meta-analyses. BMJ. 2013;346:f1326.
- He FJ, Li J, Macgregor GA. Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. BMJ. 2013;346:f1325.
- 食物環境衞生署食物安全中心. 購物卡 Shopping Cards. 營養標籤資源材料. Published 2020. Accessed March 12, 2021. https://www.cfs.gov.hk/tc_chi/programme/programme_nifl/programme_nifl_public_Resources_Shopping_Card.html
- Anderson CAM, Appel LJ, Okuda N, et al. Dietary sources of sodium in China, Japan, the United Kingdom, and the United States, women and men aged 40 to 59 years: the INTERMAP study. J Am Diet Assoc. 2010;110(5):736-745.
- 食物環境衞生署食物安全中心. 本港食物鈉含量的研究 Study on Sodium Content in Local Foods. 食物營養素. Published 2012. Accessed March 12, 2021. https://www.cfs.gov.hk/tc_chi/programme/programme_rafs/programme_rafs_n_01_14.html
- 衞生署衞生防護中心. 非傳染病直擊 2018年6月 – 注意鹽攝入量 Be Salt Aware. 非傳染病直擊 2018. Published 2018. Accessed March 12, 2021. https://www.chp.gov.hk/tc/resources/29/100013.html
- American Heart Association. Sodium Can be Sneaky Infographic. Eat Smart: Sodium. Published 2017. Accessed March 12, 2021. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/sodium/sodium-can-be-sneaky-infographic
- American Heart Association. The Salty Six Infographic. Eat Smart: Sodium. Published 2020. Accessed March 12, 2021. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/sodium/salty-six-infographic
- Zhang D, Li Y, Wang G, Moran AE, Pagán JA. Nutrition Label Use and Sodium Intake in the U.S. Am J Prev Med. 2017;53(6S2):S220-S227.
ACE21024D Apr 2021