High levels of total and low-density lipoprotein (LDL) or bad cholesterol, increase the risk of cardiovascular disease (such as stroke and heart attacks). Research has shown that lowering LDL by 1 mmol/L is estimated to reduce risk of heart attack and stroke by about 26%1. For example, if LDL drops from 3.6 mmol/L to 1.6 mmol/L, this means that the risk of stroke and heart attack can potentially be cut by about 52%.
LDL can be lowered by:
- Medications prescribed by your doctor (check with your doctor which medications can target this area)
- Diet
- Exercise (to some extent)
Diet can reduce significantly the levels of bad cholesterol, reduction by ~30%2 or more has been described in the literature. While exercise drops the bad cholesterol by a maximum of ~5%3. Medications on the other hand have comparatively have higher efficacy, and can go up to 60% reduction in LDL for some high potency agents.
So when do we need medications? Can we just do with diet and exercise? Those with higher risk for cardiovascular events of stroke and heart attack would be advised to start medications in order to control risk adequately. These higher risk individuals include those who have already been found to have severe heart artery blockages before or stroke or familial hypercholesterolemia for example.
Other individuals who are not at high risk, have the option to control their LDL cholesterol through non pharmacological means, if they so prefer. These individuals still need to control their LDL to lower their heart disease risk. Because even if risk is not high now, it accumulates with time, the longer that individual has cholesterol levels above his or her optimal level, the higher the risk. This is where diet can help. And diet has a role even for those who are at high risk of cardiac events who are on medications to control LDL, as some people still want to do what they can to bring their LDL down so that perhaps the dosage of medications could be cut down in future.
How would you know if your LDL is at an optimal level? The best thing to do is check with your doctor, and if you are Singaporean, you could also try out the heart risk calculator in the Health Buddy app, which incorporates a risk prediction model calibrated for Singaporeans. It will give you a percentage risk for the next ten years of your life and also tells you if you can further reduce your cholesterol to optimise your risk.
In the next section we will tell you how to reduce your bad cholesterol with diet.
Diet to lower LDL
3 Key Points
- Reducing saturated fat intake will result in reduction of bad cholesterol. Saturated fat is found in dairy fats and other animal fats (from the fats of chicken, pork, beef, butter, etc.), and some tropical oils like coconut and palm oil. Substitute with better fat such as olive oil, canola oil, sunflower oil. This substitution will help in lowering LDL. Replacing snacks high in saturated fats (chocolate, potato chips) with nuts like walnuts and almonds also lowers LDL. Substituting avocadoes for other unhealthy fats in the diet also lowers cholesterol, at an intake of 1 avocado a day. (Avocadoes are still high in fat so be careful not over indulge.)4
- Increasing plant protein intake. For example, taking soy or beans in replacement of animal protein like milk or meat will lower LDL. Plant protein, in substitution of animal protein has been found in a randomised controlled trial to lower LDL cholesterol independent of the amount of saturated fat the diet contains5. In the study, the diet contained about 30g of soy protein a day, equivalent to about 375g of tofu or 2 small cups of edamame beans daily.
- Increase intake of viscous fibre2, to decrease absorption of cholesterol in the intestines. Viscous fibre is found in fruits like apples and oranges, vegetables like eggplant and okra, and grains like oats and barley. Beans also have viscous fibre.
How much of the above should you eat to see effects on LDL?
A study done in Toronto2 tested a diet incorporating some of the dietary components shown to reduce LDL. The diet produced an average 35% drop in LDL. There were some key features in this diet, namely, a significant amount of viscous fibre, and plant protein.
Foods rich in viscous fibre are shown in the table below - choosing one type of food from each of the groups listed in the table every day would allow one to reach the amount of viscous fibre intake used in the study (estimated amounts for an individual with ~1800 kcal daily energy requirement).
Foods High in Viscous Fibre - Recommended Intake
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- Drink extra water as you increase your daily fibre intake. Most healthy people (without impaired heart function or kidney issues) need 9 to 12 cups a day.
- A balanced diet is key - maintain the right proportions of food groups in the diet: half plate of fruit and vegetables, quarter plate of wholegrains/low GI carbohydrate and quarter plate of good sources of protein.
Recommended healthy plate (source: Health Promotion Board)
Lastly, to continuously reap the benefits of your improved diet, keep following it! Weave it into your life, encourage your loved ones to follow you in this change and this will help you and the ones you care about reap benefits in the years to come.
Please consult your doctor with regards to cholesterol lowering medications. If you are found to be at higher cardiovascular risk, it is important that you start your cholesterol lowering medications immediately. If you already have obstructive coronary artery disease, then diet alone is not enough. You will also need cholesterol lowering medications like statins to reduce the risk of plaque rupture, hence reducing risk of heart attack.
This article is for reference. Please consult a clinical dietitian for individualised advice on how to incorporate these into one’s diet.
References:
- Gencer B, Marston NA, Im KA, et al. Efficacy and safety of lowering LDL cholesterol in older patients: a systematic review and meta-analysis of randomised controlled trials. Lancet (London, England). 2020;396(10263):1637-1643. doi:10.1016/S0140-6736(20)32332-1
- Jenkins DJA, Kendall CWC, Marchie A, et al. The effect of combining plant sterols, soy protein, viscous fibers, and almonds in treating hypercholesterolemia. Metabolism. 2003;52(11):1478-1483. doi:10.1016/S0026-0495(03)00260-9
- 2020 ESC Guidelines on Sports Cardiology and Exercise in Patients With Cardiovascular Disease: The Task Force on Sports Cardiology and Exercise in Patients With Cardiovascular Disease of the European Society of Cardiology (ESC). Eur Heart J 2020;Aug 29
- Schoeneck M, Iggman D. The effects of foods on LDL cholesterol levels: A systematic review of the accumulated evidence from systematic reviews and meta-analyses of randomized controlled trials. Nutr Metab Cardiovasc Dis. 2021;31(5):1325-1338. doi:10.1016/J.NUMECD.2020.12.032
- Bergeron N, Chiu S, Williams PT, M King S, Krauss RM. Effects of red meat, white meat, and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomized controlled trial. Am J Clin Nutr. 2019;110(1):24-33. doi:10.1093/AJCN/NQZ035
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