Why cholesterol is important and how to lower it with lifestyle choices
Although blood glucose levels tend to be the primary concern in diabetes, there are a number of other systems which may be effected secondary to the diabetes. One of the most important considerations is your cardiovascular health. I have previously discussed the various health checks you should regularly get here.
Of these considerations, cholesterol levels are one of primary concern as those suffering with diabetes can be susceptible to increased levels. Therefore, all people suffering with diabetes should have their cholesterol levels checked regularly. This is because developing diabetes can increase your risk of increasing your ‘bad’ cholesterol levels, which are associated with adverse cardiovascular events.
Cholesterol appears to be a subject not many of my patients are overly informed on and often they are confused about how they can reduce their levels through diet and lifestyle.
Fortunately, the advice lends itself well to healthy eating principles and is quite easy to understand.
First of all, cholesterol has many essential functions in the body such as transporting nutrients in the blood and keeping cells fluid. Therefore, some cholesterol is absolutely necessary for a healthy functioning body.
There are also different types of cholesterol. Low Density Lipoproteins (LDL) are considered the bad forms of cholesterol if too high. These are the ones associated with negative health outcomes if you have an excessive amount in circulation. A normal level of LDL cholesterol transports cholesterol to the cells so they can carry out their daily functions. However, if LDL levels are too high, this can lead to plaques forming in the blood vessels leading to restricted blood flow and calcification of the blood vessels. Consequently, this can lead to increased blood pressure and even heart attacks and stroke.
High density lipoproteins (HDL) are your good cholesterol and these help to mop up the bad LDL cholesterol in your system and return them to the liver.
When visiting the GP for blood tests, they will test for LDL, HDL and total cholesterol. They may also look at the total cholesterol/HDL ratio.
In diabetes, you ideally want the following levels of cholesterol:
- Total cholesterol below 4,
- LDL below 2
- HDL above 1
However, if your total cholesterol is 5 but you have a HDL of 2.5, you can see how the ratio shifts in favour of good cholesterol and therefore total cholesterol in this instance may not be the best marker. This is where the total cholesterol/HDL ratio is useful. Ideally this number is also below 4.
That said, a total cholesterol of 9 with an HDL of 4 (a total cholesterol/HDL ratio of 2.25) still means the patient has high circulating levels of LDL (5 in this instance) and may place the patient at risk because there are abnormal amounts of cholesterol in the system. Therefore, it’s important to discuss the figures with your doctor and demonstrate some lateral thinking when analysing results.
We do not totally understand cholesterols relationship with cardiovascular health as many patients present with high LDL levels and suffer no cardiovascular events. Therefore, we tend to assess the other markers which may place patients at further risk such as smoking, diet and physical activity levels.
It’s not cholesterol that causes high cholesterol
Conventional advice originally taught patients to reduce the level of cholesterol in their diet to help reduce their cholesterol levels.
Reducing foods such as eggs and shellfish were often the biggest culprits and I still see patients today who won’t eat more than 2 eggs per week because of this.
Fortunately, the great thing about health care is we are led by scientific evidence rather than opinion and hearsay and it has since been shown eating cholesterol does not cause an increase in cholesterol levels.
It is in fact high levels of saturated fat such as fatty meats, skins, full fat dairy and processed trans fats like biscuits, cakes and desserts which are associated with increased cholesterol levels.
This effect is significantly heightened if the person eating these foods is inactive and/or overweight and smokes.
Therefore, the lifestyle causes are threefold fold. Too much bad fats in the diet, too much excess fat mass carried in the body and a smoker.
Foods that reduce cholesterol
A cholesterol lowering diet is based on the basics of healthy eating. If you recognise you eat too much convenience food, high saturated animal fats or sweet treats, reducing these foods is the obvious place to start.
If you think of yourself as someone who eats healthy but still suffer with high cholesterol, there can be genetic causes. That said, it is worth ensuring you are eating the correct portion sizes and frequencies of foods for your level of activity. A good measure of this will be your current weight, BMI or total fat percentage. It is possible to eat a healthy diet in unhealthy quantities and thus carry excess fat mass.
Basing meals around vegetables and lean sources of protein will help to keep the total energy of meals lower and increase the nutrition of each meal.
Vegetables and fruit are a good sources of soluble fibre which helps to mop up cholesterol in the body and improve gut health. Current recommendations suggest people should be aiming for 30g of fibre per day. That roughly equates to managing your ‘5 portions a day minimum’ portion of fruit and vegetables.
A portion is 4 tablespoons of vegetables or 2 small fruits such as satsumas or 1 medium fruit such as an apple or half a larger fruit.
Having no more than a fist size portion of carbohydrates will also help to ensure your portions are the correct size. Aiming for wholegrain varieties such as grains, oats, and wholegrain cereals to provide your body with slow releasing sugars and help to increase your total fibre intake towards the recommended 30g each day.
Aiming to have 2 portions of fish per week, 1 oily and 1 non oily (unless you prefer oily) also helps to provide the body with the essential fatty acids it requires, which have been shown to lower LDL cholesterol.
Monounsaturated fats such as olive and rapeseed oil have also been shown to decrease LDL whilst being neutral on HDL cholesterol and therefore choosing spreads based on these oils may be more appropriate than butter or margarines. Alternatively, you may add a teaspoon of these oils to salads or foods.
There are also a number of cholesterol lowering products known as plant stanols and sterols. These have been shown to help lower cholesterol levels but are no substitute for a healthy diet.
Finally, your cooking method can have a big effect on the quality of your diet. Try steaming, grilling, baking or poaching instead of frying in fats.
Other strategies for lowering cholesterol
As mentioned, carrying too much weight is one of the main causes of high cholesterol. Therefore, if you do not have an exceptional muscle mass and your body mass index (BMI – weight in kilograms divided by height in meters squared) is over 25, you likely carry some excess weight. If your body mass index is over 30, you are defined as clinically obese. For optimal ranges, your BMI should fall between 18.5-24.9.
I mention muscle mass because exceptional levels of muscle mass will skew the BMI, for example, like in a rugby player. However, most individuals, of an age for high cholesterol, do not carry exceptional muscle mass and therefore the BMI is a reasonably valid tool.
If your BMI is high and you can physically recognise you carry excess weight and your cholesterol is high, weight loss is the first line treatment from a lifestyle perspective.
Another great way of reducing your cholesterol is to get active. Current guidelines suggest 150 minutes of moderate intensity or 75 minutes of vigorous activity can help improve many health outcomes, including lowering cholesterol. Moderate intensity describes feeling warmer than usual but still being able to hold a conversation like a brisk walk whereas vigorous activity is when you are unable to hold a conversation and are physically outside of your comfort zone.
For weight loss, activity will need to be increased to an hour plus each day.
Ideas for increasing activity can range from structured activity like swimming, cycling, running, weight lifting and/or sport to more daily life based activities such as walking, cleaning and gardening.
There is a train of thought that animal fats are not linked to an increased risk of cardiovascular problems. This is an ongoing debate, however those that make this argument are yet to have any evidence to support this.
They argue the original studies demonstrating saturated fat being linked to cardiovascular problems was flawed and admittedly, it wasn’t perfect.
However, it is very difficult to prove a single dietary cause of a health problem on a population study because so many other factors will effect the outcomes e.g. smoking, alcohol, activity, other foods routinely eaten etc.
Fat is essential for your body to function optimally. The low fat message should really be labelled the correct amount of fat. Like anything, excess amounts of anything can lead to problems. Fat is very calorie dense containing twice the calories of carbohydrate and protein and therefore extra care needs to be taken when eating it. However, a certain amount of fat in the diet is inevitable and actually good for you.
Often it is products like the cakes, biscuits, fatty cuts of meat or too much high fat dairy, which is responsible for my patients high fat intake. In turn, this can lead to over eating and increased weight and ultimately can lead to increased cholesterol levels.
However, if you eat modest amounts of the above foods, choosing full fat milk or full fat yogurt will not do you any harm. It’s only when you have a high fat intake that it becomes a problem.
Therefore, fat is not a problem, but like anything, too much fat is. Particularly the saturated and trans fats.
My advice to you would be to base your meals around vegetables and lean protein sources such as poultry, reduced fat mince, steak, fish, eggs, beans, pulses and lentils. Do this alongside incorporating modest portions of wholegrain varieties of starchy carbohydrates such as oats, wholegrain breads, new or sweet potatoes.
Make sure you watch your portion sizes, aim for your 30g of fibre per day and you may also consider a plant stanol or sterol if you wish.
Try to get as active as possible and begin to build habits which can last for life.
If you do this, you will likely see your cholesterol reduce and your health improve.