Blog Post

How to Reduce Cholesterol through Diet?

Cholesterol and Diet

Cholesterol can be a complex topic with a lot of mixed messaging.

Some commonly accepted assumptions are:

  1. High cholesterol, particularly LDL cholesterol is often a bad thing for overall health outcomes. The goal is often to reduce it.
  2. Diet, exercise, and other lifestyle factors play a role.
  3. Genetics play a role.

One of the things that make it hard to write about this topic is that is kind of a straightforward topic, but it has many layers. There are a lot of common themes that consistently work for reducing cholesterol that likely carries over to improved health, and these are the things I will be focusing on.

But the complexity arises when factoring in that there are so many ways to achieve these outcomes. People can criticise individual approaches since there might be a “better way.” Or alternatively, people will criticise the premise of aiming to broadly reduce cholesterol in general.

A Note on Cholesterol Controversy

The common simplified medical consensus is that high-density lipoprotein (HDL cholesterol) is considered “good cholesterol” and low-density lipoprotein (LDL cholesterol) is considered to be “bad cholesterol.”

If total cholesterol is high, the goal is often to reduce total cholesterol. If LDL is high, or triglycerides are high, the goal is to preferentially reduce those.

Digging deeper, some people will criticise looking at total cholesterol and highlight that the ratio of HDL to LDL cholesterol is far more important.

Then others will make the argument that LDL cholesterol being super high still is not an issue in people who are metabolically healthy outside of that. The below video is an example of this.

Personally, my recommendation if you want a nuanced review unpacking this type of debate would be to read this article from Sigma Nutrition.

Instead of me spending time focusing on the minor details, I am just going to spend the rest of the article focusing on advice that works for reducing cholesterol in a way that typically carries over to improved health outcomes.

Easy Win – Plant Sterols

Before getting into more boring advice, I wanted to give an easy win.

Plant sterols are this easy win.

Have you ever seen the products Flora Proactiv, Cholesterol Lowering Weet-Bix or Heart Active Milk?

Flora Proactiv

These are Australian products, so may not be relevant if you live elsewhere.

Heart Active Milk

These products typically have marketing around how they reduce cholesterol by an average of 9-10% in around 6 weeks.

The thing is, they are really just regular weet-bix, margarine and low-fat milk, except they have plant sterols added.

Cholesterol lowering Weet-bix

My preference is to jump straight to the source and find a plant sterols supplement specifically instead of using those products.

The recommended dosage is 2-3g plant sterols per day.

Supplementing plant sterols instead of using these products can be easier because to get the recommended amount of plant sterols, you would need to eat these foods consistently in the serving sizes they recommend.

For context the serving sizes required to get 2-3g would be:

  • 2x Cholesterol Lowering Weet-Bix
  • 20g Flora Proactiv
  • 2-3 cups of Heart Active Milk

Having this 2-3g amount likely will reduce LDL cholesterol by around 10% within 6 weeks, on average. Going higher than this amount is unlikely to lead to further benefits. The

It is rare that taking a supplement or anything like that will lead to significant results. But that is why this is an easy win. It is not magical or anything, but it is probably the easiest way to get a 10% reduction in cholesterol without medication.

Decrease Body Fat

If there is one piece of value I have to add with this article that is underappreciated, it is that body fat is more strongly linked with serum cholesterol levels than the majority of other variables.

If you google how to reduce cholesterol, a lot of the information will be regarding saturated fat intake and other dietary variables I will mention later.

Discussion around body fat and weight is often not mentioned for a variety of reasons, partly because it is not a popular message.

It is worth being aware of because:

  1. Almost every study that involves a loss of >5% of body weight results in an improvement in cholesterol levels on average, or a reduction in the need for cholesterol medication.
  2. The same cannot be said about improvements in dietary quality without changes in body composition.

One example of this I will use is a study called The SMILEs Trial. It was a study on nutrition for depression, but there finding in relation to cholesterol were particularly relevant for this section.

The participants dramatically improved their dietary quality. They ate more healthy fats, less saturated fat, more wholegrains, more fibre, more fruits and vegetables.

The participants in this study did a lot of the things from a dietary perspective that are typically recommended. But it was an intentionally weight neutral approach. They dramatically reduced their intake of junk food, but they ate enough calories to maintain their weight.

Energy Balance

At the end of the study, their cholesterol remained unchanged.

After such a big change, you would assume there would be big changes in cholesterol. But there was not. This is just one example, but I am making the point that while these changes matter and often do help, they are only one piece of the puzzle.

Body composition is likely a more important point. It is rarer for people who are lean to have high cholesterol in comparison to people at higher body fat percentage.

As a side note, I guarantee a lot of people will read this and will think of examples that are exceptions to this. For example, you might know somebody who is lean and has high cholesterol.

That happens. We are just talking about percentages and risk factors here. Leaner people can have high cholesterol. They are just less likely to have high cholesterol. And reductions in body fat percentage on average reduce cholesterol.

Reduce Saturated Fat and Trans-Fat Intake

Trans fats are very clearly linked with adverse outcomes, including cardiovascular disease and stroke. That point is rarely debated.

At minimum, minimising trans fat intake is a good idea for most people.

Saturated fat is a bit more complex. A lot of large-scale research looking at saturated fat and all-cause mortality does not identify a link that is anywhere near as strong as you would expect based on public health messages.

These public health messages are not just made up out of thin air though. They have rationale behind them.

If you dig deeper into more controlled studies, high saturated fat intakes do appear to increase LDL cholesterol on average.

It still makes sense to reduce saturated fat intake if it is an aspect of your diet that is currently high.

Increase Omega 3’s

Omega 3 Supplements
Nutritional Supplement, Vitamin, Women, Healthy Lifestyle, Capsule – Medicine

Fish oil has strong evidence for reducing triglyceride levels.

There is mixed evidence for and against fish oil helping reduce cardiovascular disease.

The research on fish oil and cardiovascular disease looks mixed, but when you dig into the research deeper, a few things become apparent:

  • It is safe to assume that those who have lower omega 3 intake through their diet, or lower baseline omega 3 status, likely benefit more from supplementation.

  • Studies done on those who have already experienced issues from a heart-health perspective appear to find more benefit than those who had no issues prior.

  • People on cholesterol lowering medication can have LDL levels that are low, but still have high triglycerides. Omega 3’s can help here.

  • Studies that have >850mg combined EPA and DHA, with larger sample sizes and >2 years of follow up are more likely to show positive outcomes than those that do not.

  • Studies using higher dosages in general appear to show more benefit. Utilising 2-4g of fish oil appears to be more effective than 1g.

  • The benefits are typically not massive. Even in research showing results, it is typically a 10-20% reduction in the risk of things like stroke and heart attacks.

Increasing omega 3 intake can be done with or without supplements. It could be done through increasing intake of fish itself to 2-3x per week. Or it could be done through plant-based options too.

Increase Other Healthy Fats

Dietary Fat

The term “healthy fats” is more of a colloquial term than a scientific one. It is obviously not that simple. It is simply referring to monounsaturated and polyunsaturated fats.

This is another topic that can be incredibly complex if you dig deep enough.

Since it does not move the needle as much as other aspects, keeping it brief for this section is probably justified.

The research on the topic indicates that replacing saturated fat intake with EITHER monounsaturated or polyunsaturated fats is linked with reduced LDL cholesterol.

Thoughts on Dietary Cholesterol

Eggs

A common piece of advice given to people looking to reduce their cholesterol is to reduce their intake of eggs.

The logic focused on egg yolks being high in dietary cholesterol.

Dietary cholesterol is not our focus though. Blood cholesterol is what we care about.

And because we synthesis cholesterol in our own body as well, that means that dietary cholesterol is not our sole priority.

At two ends of the spectrum people will say things like:

  1. We need to minimise egg intake since they are high in cholesterol.
  2. Dietary cholesterol does not matter at all since it has little relevance for our blood cholesterol.

There is a bit of truth to both. The answer is in the middle.

A small percentage of most people’s serum cholesterol comes from dietary cholesterol.

This would be even higher in those who have high intakes of dietary cholesterol. And it would be non-existent in those who follow exclusively plant-based diets.

Something that skews the numbers is that dietary cholesterol rarely comes alone. It often comes alongside saturated fat. Eggs happen to be relatively low in saturated fat. But most other sources of dietary cholesterol are high in saturated fat.

Overly focusing on dietary cholesterol probably should not be the main priority. It is another piece of the puzzle worth being aware of, so it should not be ignored. But it is less relevant than other factors mentioned prior to this.

Increase Soluble Fibre

Food sources of each type of fibre
Image via The Savvy Dietitian

Soluble fibre is a type of fibre which becomes a bit of a gel-like substance in our intestines that theoretically traps fats a bit and lowers cholesterol.

Increasing fibre intake in general to >25g per day has been linked with reductions in cholesterol.

Thinking critically about it though, these outcomes can be affected by other variables. For example, consuming more fibre typically leads to a lower consumption of total calories. This can obviously factor into cholesterol levels.

Insoluble fibre likely indirectly affects cholesterol levels due to these variables.

But soluble fibre directly affects it due to the mechanism outlined above.

On average, actively trying to increase soluble fibre intake reduces LDL cholesterol by 5-10%.

Specific fibre types appear to outperform in this regard too.

Beta-glucan in oats is a specific type of soluble fibre that is strongly linked with reductions in cholesterol. One study found that 3g of beta-glucan per day for 4 weeks contributed to an 8.1% decrease in total cholesterol and a 11.6% decrease in LDL cholesterol.

Oats

Adding a psyllium-based fibre supplement such as Metamucil has been linked with reductions in cholesterol of 6-24%. The upper end of that range is mostly relevant for those with higher cholesterol levels at baseline.

Metamucil

Alcohol

Alcoholic Beverages

Low to moderate intakes of alcohol likely are not a big deal. Heck, light alcohol intake has actually been linked with increased HDL cholesterol.

Higher alcohol intakes are clearly linked with increased LDL cholesterol and triglycerides though.

Alcohol also makes it harder to improve body composition due to a combination of the calories added, as well as the reductions in muscle protein synthesis and sleep quality, amongst other things.

If looking to improve cholesterol, reductions in alcohol intake are typically going to help.

Summary

Cholesterol can be a complex topic, but there are a lot of common themes that help.

Some of these are:

  • Adding plant sterols.
  • Improving body composition.
  • Reducing saturated fat intake.
  • Increasing intake of omega-3s and other healthy fats.
  • Reducing dietary cholesterol if it is particularly high.
  • Increasing fibre intake, particularly soluble fibre.
  • Reducing alcohol intake if relevant.

While cholesterol can be a complex topic, these pieces of advice are simple and straight forward. There are a lot of details that can be argued about, but implementing the above advice is likely to lead to good outcomes regardless.

By Aidan Muir

Aidan is a Brisbane based dietitian who prides himself on staying up-to-date with evidence-based approaches to dietetic intervention. He has long been fascinated by all things nutrition, particularly the effects of different dietary approaches on body composition and sports performance. Due to this passion, he has built up an extensive knowledge base and experience in multiple areas of nutrition and is able to help clients with a variety of conditions. One of Aidan’s main strengths is his ability to adapt plans based on the client's desires. By having such a thorough understanding of optimal nutrition for different situations he is able to develop detailed meal plans and guidance for clients that can contribute to improving the clients overall quality of life and performance. He offers services both in-person and online.