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High levels of total and low-density lipoprotein (LDL) or bad cholesterol, increase the risk of cardiovascular disease. 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 to lower LDL

We are usually told to restrict our diet to reduce bad cholesterol or LDL. That is true, for the reduction of saturated fat intake will result in reduction of LDL. Saturated fat is found in dairy fats and other animal fats (from the fats of chicken, pork, beef, etc. ), and some tropical oils like coconut and palm oil. Read more about the various diet components we can consume in a balanced heart healthy diet here. 

Besides restricting intake of certain foods, we should also add certain foods to our diet to help lower LDL. Numerous studies2 have shown that some foods help more than others.

In Figure 1 below which shows the effects of foods on LDL cholesterol levels, the size of the circle drawn around the food represents the strength of the evidence - the bigger the circle drawn around the food is, the stronger the evidence of the effect of the food on LDL, while the lower the position of the food on the figure, the greater the ability of the food to lower LDL.

 The effects of foods on LDL cholesterol levels
Figure 1 (source: The effects of foods on LDL cholesterol levels2)

You may notice from the figure that fish has not been shown to reduce LDL, having what looks like a neutral effect. However, for fish and also some other foods, they are able to reduce the risk of heart attack and stroke which are independent of LDL reduction.

LDL-lowering food: How much to eat?

While Figure 1 serves as a good reference in helping us choose more of the LDL-lowering foods, how much should we eat to see adequate effects? 

A study done in Toronto3 tested a diet incorporating some of the dietary components shown to reduce LDL. The diet, based on individuals with a 1,800 kcal daily caloric requirement, 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 (in keeping with the evidence shown in Figure 1).

Viscous fibre helps to prevent absorption of cholesterol in the intestines. It is found in many plant foods like apples, oats, barley, lady fingers (okra) and eggplant (brinjal). In the study, received about 15g of viscous fibre a day in the form of oats, barley, eggplant and okra. 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. 

​Foods High in Viscous Fibre
​½ cup cooked whole grains containing 1-2g of viscous fibre 
Barley, brown rice, oatmeal, oat bran

½ cup plant protein foods containing 1-3g of viscous fibre 
Black eyed peas, chickpeas (garbanzo), black beans, kidney beans, navy beans (baked beans), soybeans, edamame beans, pinto beans

Foods with healthy fats containing 1-3g of viscous fibre
¼ avocado, 1 tablespoon whole chia seeds, 2 tablespoon ground flax seeds, ¼ cup sunflower seeds, 28g almonds/ peanuts/ walnuts



½ cup cooked vegetables or 1 cup raw vegetables containing 1-3g of viscous fibre 
Broccoli, cauliflower, carrots, brussel sprouts, cabbage, long beans, string beans, french beans, okra, eggplant, turnips

Starchy vegetables containing 2-3g of viscous fibre
  • 1 medium sweet or white potato
  • ½ cup green peas
  • ½ cup pumpkin
Fruits containing 1-3g of viscous fibre
  • 1 medium apple, banana, orange, peach, pear or mango
  • 2 fresh apricots or plums
  • ½ cup blackberries or 1 cup raspberries/ strawberries

Drink extra water as you increase your daily fibre intake. Most healthy people (without heart or kidney issues) need 9 to 12 cups a day.

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 contains4. In the study3, the diet contained about 30g of soy protein a day, equivalent to about 375g of tofu or 2 small cups of edamame beans daily.

The LDL lowering effects of the plant protein can also be due to components present in plant-based foods (e.g. plant-derived phytochemicals, micronutrients, differences in amount and type of dietary fibre) when they are used to substitute animal protein like red and white meat in the diet.

The diet study also contained about 30g of almonds a day. Almonds contain fibre, plant protein and phytosterols, which are all helpful in lowering LDL.

It is interesting to note that the diet study showed an average drop of 35% in LDL cholesterol after just 2 weeks on the diet, and these levels were maintained for 4 weeks which was the duration of the study3. 

A balanced diet is key

Now that we understand how a diet containing viscous fibre and plant protein in the amounts described can help lower bad cholesterol, coupled with eating foods with lower saturated fats, it is also important to maintain the right proportions of food groups in our diet. Follow the proportions shown in the recommended healthy plate below to ensure you achieve a balanced nutrition. 

 
Recommended healthy plate (source: Health Promotion Board)

Lastly, to continuously reap the benefits of your improved diet, you have to follow it religiously! Weave it into your life, encourage your loved ones to follow you in this change and you will find that this will help you 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:
  1. 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
  2. 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
  3. 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
  4. 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