What is the link between the keto diet and cholesterol? Does eating a keto diet raise bad cholesterol and increase the risk of heart disease?
It’s an understandable conclusion that a keto diet that is high in fat must be high in bad cholesterol – but nothing could be further from the truth. Plenty of modern, scientific research shows that high-fat, low-carb diets such as keto can optimise cholesterol levels and improve your heart health.
Before we discuss this topic further, let’s define what cholesterol is.
WHAT IS CHOLESTEROL?
There are two classifications of fats in the human body: triglycerides and cholesterol.
Triglycerides is not cholesterol but it’s typically measured in a cholesterol test. Triglycerides are fatty-acid molecules that store energy for later use and can be broken down for energy. Too much triglycerides in the blood can increase the risk of developing diabetes, heart diseases and other life-threatening conditions.
Rising triglyceride levels increase your risk of developing atherosclerosis (the build-up of fatty plaque on artery walls, causing blockages which increases the risk of heart disease, heart attack and stroke).
Cholesterol is a waxy, fat-like substance that occurs naturally in your body and is found in all your cells.
Cholesterol supports functions in the body such as building hormones, maintaining the integrity of cell membranes and aiding the absorption of vitamins. It is especially important for your brain, nerves and skin.
Cholesterol is produced by your liver and you can also obtain it from your diet.
Cholesterol is vital for good health and shouldn’t be feared in its normal range. It is absolutely essential to your health and plays a vital role in hormone production, cell health, cell generation and cell function. But having too much cholesterol is a risk-factor in heart disease.
“GOOD CHOLESTEROL” (HDL) AND “BAD CHOLESTEROL” (LDL)
You will likely hear terms such as HDL (“good cholesterol”) and LDL (“bad cholesterol”). HDL and LDL are not cholesterol molecules but rather they’re lipoproteins that help transport cholesterol around the body.
HDL: GOOD CHOLESTEROL
- HDL – High Density Lipoproteins, commonly termed “good cholesterol”.
- HDL transports cholesterol around the body and collects and returns unused cholesterol back to the liver to be recycled or destroyed, i.e. it helps prevent other cholesterol from accumulating and clogging your arteries
- Some research suggests that HDL may also have anti-inflammatory effects.
- HDL makes up about 20-30% of total cholesterol.
- The higher your HDL, the better. Over 60mg/dL is good.
- There are many things that can lower HDL – Type 2 diabetes, not exercising enough, smoking, being overweight.
LDL: BAD CHOLESTEROL
- LDL – Low Density Lipoproteins, commonly termed “bad cholesterol”.
- LDL moves slowly through and is vulnerable to oxidizing agents known as “free radicals”. Once oxidised, LDO can embed itself into arterial walls and impede blood flow or cause inflammation that can cause further build up
- Size and density matters. LDL comes in various sizes and densities. Larger LDL particles are considered healthier whereas smaller LDL particles pose a higher risk of heart disease.
- LDL makes up 60-70% of your total cholesterol.
- The lower your LDL, the better. Under 100mg/dL is good.
- LDL causes build-up of plaque inside areas, increasing risk of heart disease and stroke. LDL generally rises if you eat a lot of processed foods, in particular, foods containing trans fats.
- LDL is considered the most important for assessing risk of heart disease. (There is also a type of cholesterol called VLDL (Very Low Density Lipoproteins. VLDL makes up about 10-15% of your total cholesterol). This is another undesirable type of cholesterol and the precursor to LDL.
So, just talking about “high/increasing” cholesterol or “low/decreasing” cholesterol is not enough because we need to distinguish between HDL and LDL
A high cholesterol reading in itself is not necessarily bad. If you have a borderline high level of cholesterol for example but much of it is the good cholesterol – HDL – that’s not a problem. What your doctor is looking out for are high levels of LDL and/or high levels of triglycerides.
THE KETO DIET AND CHOLESTEROL
Now that we have a better understanding of what cholesterol is, we can look at how the keto diet and cholesterol are related.
According to a recent study published in the British Journal of Nutrition, subjects on a low-carb high-fat i.e. ketogenic diet were compared to those on a low-fat diet. After a year, the results were staggering. The group on the keto diet showed double the average amount of HDL – good cholesterol – than the group on the low-fat diet. As outlined above, when it comes to HDL, the higher the levels, the better.
Other studies have been conducted on LDL showing that a low-carb diet had a favourable effect on LDL concentration, size and quantity, helping reduce LDL across the board. (When it comes to LDL, the lower, the better).
Finally, studies have also shown improvements in triglyceride levels when carbs and sugar are replaced with fat.
So when it comes to the keto diet and cholesterol, it’s a double win: keto increases the amount of HDL (good cholesterol) and lowers the amount of LDL (bad cholesterol). Keto is a great diet for heart health and for improving your cholesterol profile.
So, when you restrict carbohydrates and sugar and the majority of your calories come from animal fats, coconut oil and unsaturated fats like fish, nuts, avocado and olive oil, it’s highly likely that you will improve your cholesterol levels and fats profile.
KETO DIET AND CHOLESTEROL: 7 WAYS TO LOWER YOUR CHOLESTEROL LEVELS
If you’re still concerned about your cholesterol levels or want to lower your LDL/triglyceride levels, there are some things you can do without abandoning the ketogenic way of eating.
Here are a 7 ways you can reduce your total and LDL cholesterol levels while maintaining a keto or low-carb lifestyle. Consider trying them in this order.
- Lifestyle changes. Stop smoking (if you need help quitting, speak to your doctor or pharmacist); only drink moderately and exercise more (even 20 minutes a day helps).
- Only eat when you’re hungry. This is good health advice in general. It will help with weight, diabetes, heart disease, energy levels, sleep – every facet of your life. Most of us are drowning in food and eat far too much. And certainly stop eating when you’re bored.
- Consider intermittent fasting. Intermittent fasting (IF) may reduce cholesterol levels. There are variations of IF, but one of the more popular ones is the 16:8 (fast for 16 hours; an eating window of 8 hours). Another popular form of IF is the 5:2 program where you eat normally for five days per week, then restricting your calorie intake to 500–600 calories on the other two days. Choose what works for you. Time restricted eating can significantly reduce LDL.
- Avoid butter coffee. Often referred to by the brand name bullet coffee, butter coffee is useful for those who want a convenient way to boost their fat intake. But if you’re trying to lower overall cholesterol, you may want to avoid drinking this. This alone can normalise elevated cholesterol levels.
- Eat foods higher in unsaturated fats instead of saturated fats. There is nothing wrong with certain saturated fats but if you’re trying to reduce your overall cholesterol, eat more unsaturated fats like olive oil, macadamia nuts/oil, fatty fish and avocados. Whether it will improve your health is unknown, but it will likely lower your cholesterol. And if your cholesterol levels are abnormally high that may be enough of a reason, to minimise potential risk.
- Eat LDL-lowering, keto-friendly foods. These include: avocados, green vegetables, cocoa/dark chocolate, nuts and seeds
- Eat slightly more carbs. The keto diet requires you to eat less than 25g of carbs a day. This may genuinely be too low for some people. Keto allows some flexibility and you can go as high as 100g of carbs, max, per day. Keeping carbs as low as you can will help lower your cholesterol. And remember to choose good, unprocessed carbs like lentils, beans, vegetables rather than wheat flour.
The keto diet does not increase bad cholesterol levels but can actually lower it while boosting good cholesterol. While concerns about the keto diet and cholesterol are understandable, it is a hangover from decades of incorrect advice that “fat is bad”.
You can eat a keto diet without worrying about cholesterol.