High Cholesterol Levels? Can diet and exercise alone control our cholesterol levels?
Have you done your recent health screening with your doctor? And your doctor told you that you possibly have high cholesterol levels? Or you know that you persistently have slightly higher cholesterol levels than usual, but not really done anything about it? Or have you tried all sorts of lifestyle modifications and still not really seeing any improvement? Or are you just in denial? Cannot accept the fact that you possibly have a “chronic disease”?
Did you know that high cholesterol levels can also be a “silent killer” because you may not get any symptoms till it's too late? For some patients, the first time they realise that they have high cholesterol levels is when they get a heart attack or stroke!
Firstly, let's discuss what is cholesterol and what levels of cholesterol are considered bad for us.
Cholesterol is a soft, fat-like substance used to form certain tissues in the body, especially nerves. Your body derives the cholesterol which it needs from your daily diet. The fat in the food which you consume is digested in the body and taken to the liver, where it is processed into cholesterol.
The two main types of cholesterol are low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol.
LDL cholesterol is commonly referred to as “bad” cholesterol because it carries fat from your liver to other parts of the body. The higher the level of LDL in your blood, the greater the likelihood that cholesterol will deposit within the walls of your blood vessels. This in turn increases your risk of developing blockages in the heart and brain blood vessels, which leads to increased of heart attack and stroke
HDL cholesterol is called “good” cholesterol because it is believed to help your body get rid of cholesterol by transporting fat and LDL cholesterol deposits to the liver for breakdown, thereby “cleansing” the arteries.
Thus, to protect yourself against cardiovascular diseases like heart attack and stroke, you would want your HDL (good) cholesterol level to be high (above 1.0mmol/dL) and your LDL (bad) cholesterol level to be low (lower than 2.6mmol/dL).
Your friendly neighborhood doctor may be in a better position to advise you on what the target cholesterol levels should be for you.
But the point is, the lower the bad LDL cholesterol, the better. Conversely, the higher the good HDL cholesterol, the better.
So how do we decrease the bad cholesterol and increase the good cholesterol?
Increasing the good cholesterol levels - Exercise!
Studies have shown that the benefits of exercise on cholesterol levels can account for nearly 20% of exercise-related risk reduction in cardiovascular disease.
Aerobic exercise can reduce the bad cholesterol levels moderately, with a drop of approximately 0.23 mmol/L drop over 6 months of exercise.
In some studies, aerobic exercise has shown to have a more pronounced effect on increasing the amount of good cholesterol in the bloodstream with an increase by approximately 11% with just moderate amounts of aerobic exercise alone.
So it's clear that exercise is good for both lowering bad cholesterol, but even better for increasing good cholesterol levels. But what kind of exercise should we be doing?
What kind of exercise is good? How much exercise to do per day, per week? I don’t have time to exercise, how?
Before starting any exercise session, please kindly visit your friendly neighbourhood GP / Family Doctor for a full medical check up, to make sure you do not have any other hidden risk factors that you are not aware of.
Aerobic exercise should still form the main bulk of exercise, with other forms like resistance training and stretching as adjuncts.
I personally like to use the FITT (Frequency, Intensity, Time, Type) Model to recommend exercise to patients. However, it would be best if you make an appointment for a formal exercise prescription with your preferred EIMS Primary Care Physician.
At least 4 training sessions per week, daily exercise if possible.
In particular for those who are overweight, a minimum of 5 training sessions per week is strongly recommended.
Moderate to vigorous intensity aerobic exercise, which means you should not be able to speak in full sentences while exercising, alternatively if you wear a heart rate monitor, exercise within 64 to 75% of maximal heart rate (calculated using 220-age).
30 to 60 minutes per session, with an average of at least 40 minutes per session.
For those who are overweight or obese, to promote and maintain weight loss, at least 50 to 60 minutes per session of moderate intensity exercise is recommended.
Any type of aerobic activity but choose an activity that you can sustain for 30 to 60 minutes.
Examples include brisk walking, jogging, swimming and cycling.
Above exercise regimen sound too overwhelming? Can I start slow first?
Of course you should start slow, and increase slowly. After medical clearance with your friendly neighbourhood doctor, preferably one who is a certified EIMS Primary Care Physician, you should probably start with a low intensity form of aerobic exercise.
The caveat is to keep the number of sessions per week at a minimum of 4 sessions, with at least 40 min per session. Find a time to squeeze this workout in, whether it be lunch break, waking up 30 minutes earlier in the morning or setting aside the children’s post bed-time for a quick 30 minute work-out.
Don’t stress yourself out too much initially. Slowly build up your aerobic fitness over time. In about 2 to 3 weeks, you will definitely notice some improvement in your aerobic fitness, and that’s the time to start increasing your exercise intensity. As a side effect, you will probably feel better in general.
Acute bouts of exercise, like what weekend warriors do, are unlikely to improve blood cholesterol levels. It is the sustained effort of at least 3 months of regular aerobic exercise, that results in an improvement in any cholesterol levels.
How can I reduce my bad cholesterol levels quickly?
There is this old saying among sports physicians: You can not out burn a bad diet. What this means is that, no matter how much aerobic exercise you do, no matter how active you are, if your diet is bad, you will have cholesterol problems.
Does this mean I have to give all these up? Laksa, oyster omelette, mee goreng, mee rubus, briyani?
Absolutely not! I love all my local foods, the oilier, the better it tastes! If I can’t cut these out from my diet, how can I possibly tell my patients to abstain from all these?
Pick a sustainable diet routine.
I find that the most successful patients who modified their diet are not those who go on faddish, unsustainable diets. These diets are probably sustainable for around 2 to 4 weeks, but beyond 8 weeks? If we can’t sustain the diet, how can we possibly expect the effects of these “good diets” to continue?
So what do we do then? My advice is simple. Get a healthy diet 80% or 90% of the week, and for 10% to 20% of the rest of the week, let’s enjoy our delicious food. But the caveat is, during the 80 to 90% of the time, we should be disciplined with our diet.
What is it in the diet that we should particularly look out for?
It is true that people with high cholesterol levels should limit their red meat intake, including beef.
Generally, you should be avoiding saturated fat, which is responsible for the high level of bad cholesterol. You can find saturated fat in red meat, such as beef, pork, mutton, lamb, full cream dairy and tropical oils (palm and coconut oil).
Other sources which contain high amounts of bad cholesterol include egg yolk, squid, and shellfish such as prawns and crab.
This is all too much for me to understand. Can someone break it down for me?
I recommend you make an appointment with your friendly neighbourhood dietician or nutritionist or doctor to discuss what is in your diet that needs improvement.
In addition, consider seeing a doctor who is EIMS - (Exercise is Medicine Singapore) trained, to firstly review any additional undiagnosed risk factors before secondly giving an exercise prescription, which is specifically tailored to you.
In conclusion, I’m confident that if you have a good diet 80 to 90% of the time, coupled with at least 150 minutes of moderate to vigorous exercise a week, your cholesterol levels will be optimised.
But if by some chance you still need help with your cholesterol levels, please do visit your friendly neighbourhood doctor!
By Dr Lee Joon Loong
MBBS (Australia), EIMS-certified Primary Care Physician
Medical Director, Paddington Medical
Exercise is Medicine Singapore, Exercise Prescription Guide, Dr B Tan, Dr Ng CS, Dr I Lim, CGH (2015)
Singapore Heart Foundation - http://www.myheart.org.sg/article/about-the-heart-and-heart-disease/risk-factors/high-blood-cholesterol/191
Wang and Xu, Effects of aerobic exercise on lipids and lipoproteins, BMC (2017), https://lipidworld.biomedcentral.com/articles/10.1186/s12944-017-0515-5