Have you had a blood test to check your cholesterol level? These check the different blood fat components:

• total cholesterol
• LDL (low-density lipoprotein), which is sometimes called “bad cholesterol”
• HDL (high-density lipoprotein), which is sometimes called “good cholesterol”
• triglycerides.

Your clinician then compares your test results to normal ranges – and may use ratios to compare different types of cholesterol.

High blood cholesterol is a major risk factor for cardiovascular disease. This is a broad term that includes disease of blood vessels throughout the body, arteries in the heart (known as coronary heart disease), heart failure, heart valve conditions, arrhythmia and stroke.

So what does cholesterol do? And what does it mean to have a healthy cholesterol ratio?

What are blood fats?

Cholesterol is a waxy type of fat made in the liver and gut, with a small amount of pre-formed cholesterol coming from food.

Cholesterol is found in all cell membranes, contributing to their structure and function. Your body uses cholesterol to make vitamin D, bile acid, and hormones, including oestrogen, testosterone, cortisol and aldosterone.

When there is too much cholesterol in your blood, it gets deposited into artery walls, making them hard and narrow. This process is called atherosclerosis.

Cholesterol is packaged with triglycerides (the most common type of fat in the body) and specific “apo” proteins into “lipo-proteins” as a package called “very-low-density” lipoproteins (VLDLs).

These are transported via the blood to body tissue in a form called low-density lipoprotein (LDL) cholesterol.

Excess cholesterol can be transported back to the liver by high-density lipoprotein, the HDL, for removal from circulation.

Another less talked about blood fat is Lipoprotein-a, or Lp(a). This is determined by your genetics and not influenced by lifestyle factors. About one in five (20%) of Australians are carriers.

Having a high Lp(a) level is an independent cardiovascular disease risk factor.

Knowing your numbers

Your blood fat levels are affected by both modifiable factors:

• dietary intake
• physical activity
• alcohol
• smoking
• weight status.

And non-modifiable factors:

• age
• sex
• family history.

What are cholesterol ratios?

Cholesterol ratios are sometimes used to provide more detail on the balance between different types of blood fats and to evaluate risk of developing heart disease.

Commonly used ratios include:

1. Total cholesterol to HDL ratio

This ratio is used in Australia to assess risk of heart disease. It’s calculated by dividing your total cholesterol number by your HDL (good) cholesterol number.

A higher ratio (greater than 5) is associated with a higher risk of heart disease, whereas a lower ratio is associated with a lower risk of heart disease.

A study of 32,000 Americans over eight years found adults who had either very high, or very low, total cholesterol/HDL ratios were at 26% and 18% greater risk of death from any cause during the study period.

Those with a ratio of greater than 4.2 had a 13% higher risk of death from heart disease than those with a ratio lower than 4.2.

2. Non-HDL cholesterol to HDL cholesterol ratio (NHHR)

Non-HDL cholesterol is the total cholesterol minus HDL. Non-HDL cholesterol includes all blood fats such as LDL, triglycerides, Lp(a) and others. This ratio is abbreviated as NHHR.

This ratio has been used more recently because it compares the ratio of “bad” blood fats that can contribute to atherosclerosis (hardening and narrowing of the arteries) to “good” or anti-atherogenic blood fats (HDL).

Non-HDL cholesterol is a stronger predictor of cardiovascular disease risk than LDL alone, while HDL is associated with lower cardiovascular disease risk.

Because this ratio removes the “good” cholesterol from the non-HDL part of the ratio, it is not penalising those people who have really high amounts of “good” HDL that make up their total cholesterol, which the first ratio does.

Research has suggested this ratio may be a stronger predictor of atherosclerosis in women than men, however more research is needed.

Another study followed more than 10,000 adults with type 2 diabetes from the United States and Canada for about five years. The researchers found that for each unit increase in the ratio, there was around a 12% increased risk of having a heart attack, stroke or death.

They identified a risk threshold of 6.28 or above, after adjusting for other risk factors. Anyone with a ratio greater than this is at very high risk and would require management to lower their risk of heart disease.

3. LDL-to-HDL cholesterol ratio

LDL/HDL is calculated by dividing your LDL cholesterol number by the HDL number. This gives a ratio of “bad” to “good” cholesterol.

A lower ratio (ideal is less than 2.0) is associated with a lower risk of heart disease.

While there is lesser focus on LDL/HDL, these ratios have been shown to be predictors of occurrence and severity of heart attacks in patients presenting with chest pain.

If you’re worried about your cholesterol levels or cardiovascular disease risk factors and are aged 45 and over (or over 30 for First Nations people), consider seeing your GP for a Medicare-rebated Heart Health Check.

Clare Collins, Laureate Professor in Nutrition and Dietetics, University of Newcastle and Erin Clarke, Postdoctoral Researcher, Nutrition and Dietetics, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This week the World Health Organization (WHO) released new guidelines recommending people switch the regular salt they use at home for substitutes containing less sodium.

But what exactly are these salt alternatives? And why is the WHO recommending this? Let’s take a look.

A new solution to an old problem

Advice to eat less salt (sodium chloride) is not new. It has been part of international and Australian guidelines for decades. This is because evidence clearly shows the sodium in salt can harm our health when we eat too much of it.

Excess sodium increases the risk of high blood pressure, which affects millions of Australians (around one in three adults). High blood pressure (hypertension) in turn increases the risk of heart disease, stroke and kidney disease, among other conditions.

The WHO estimates 1.9 million deaths globally each year can be attributed to eating too much salt.

The WHO recommends consuming no more than 2g of sodium daily. However people eat on average more than double this, around 4.3g a day.

In 2013, WHO member states committed to reducing population sodium intake by 30% by 2025. But cutting salt intake has proved very hard. Most countries, including Australia, will not meet the WHO’s goal for reducing sodium intake by 2025. The WHO has since set the same target for 2030.

The difficulty is that eating less salt means accepting a less salty taste. It also requires changes to established ways of preparing food. This has proved too much to ask of people making food at home, and too much for the food industry.

Enter potassium-enriched salt

The main lower-sodium salt substitute is called potassium-enriched salt. This is salt where some of the sodium chloride has been replaced with potassium chloride.

Potassium is an essential mineral, playing a key role in all the body’s functions. The high potassium content of fresh fruit and vegetables is one of the main reasons they’re so good for you. While people are eating more sodium than they should, many don’t get enough potassium.

The WHO recommends a daily potassium intake of 3.5g, but on the whole, people in most countries consume significantly less than this.

Potassium-enriched salt benefits our health by cutting the amount of sodium we consume, and increasing the amount of potassium in our diets. Both help to lower blood pressure.

Switching regular salt for potassium-enriched salt has been shown to reduce the risk of heart disease, stroke and premature death in large trials around the world.

Modelling studies have projected that population-wide switches to potassium-enriched salt use would prevent hundreds of thousands of deaths from cardiovascular disease (such as heart attack and stroke) each year in China and India alone.

The key advantage of switching rather than cutting salt intake is that potassium-enriched salt can be used as a direct one-for-one swap for regular salt. It looks the same, works for seasoning and in recipes, and most people don’t notice any important difference in taste.

In the largest trial of potassium-enriched salt to date, more than 90% of people were still using the product after five years.

Making the switch: some challenges

If fully implemented, this could be one of the most consequential pieces of advice the WHO has ever provided.

Millions of strokes and heart attacks could be prevented worldwide each year with a simple switch to the way we prepare foods. But there are some obstacles to overcome before we get to this point.

First, it will be important to balance the benefits and the risks. For example, people with advanced kidney disease don’t handle potassium well and so these products are not suitable for them. This is only a small proportion of the population, but we need to ensure potassium-enriched salt products are labelled with appropriate warnings.

A key challenge will be making potassium-enriched salt more affordable and accessible. Potassium chloride is more expensive to produce than sodium chloride, and at present, potassium-enriched salt is mostly sold as a niche health product at a premium price.

If you’re looking for it, salt substitutes may also be called low-sodium salt, potassium salt, heart salt, mineral salt, or sodium-reduced salt.

A review published in 2021 found low sodium salts were marketed in only 47 countries, mostly high-income ones. Prices ranged from the same as regular salt to almost 15 times higher.

An expanded supply chain that produces much more food-grade potassium chloride will be needed to enable wider availability of the product. And we’ll need to see potassium-enriched salt on the shelves next to regular salt so it’s easy for people to find.

In countries like Australia, about 80% of the salt we eat comes from processed foods. The WHO guideline falls short by not explicitly prioritising a switch for the salt used in food manufacturing.

Stakeholders working with government to encourage food industry uptake will be essential for maximising the health benefits.

Xiaoyue (Luna) Xu, Scientia Lecturer, School of Population Health, UNSW Sydney and Bruce Neal, Executive Director, George Institute Australia, George Institute for Global Health

This article is republished from The Conversation under a Creative Commons license. Read the original article.