Can you lower cholesterol?
Some time ago my other half was diagnosed with having high cholesterol. He's not a smoker, obese nor has other risk factors like diabetes or heart disease but does come from a family where there is a family history. He was told to stay away from eggs, red meat, dairy and pastry. Onto boring foods he remarked. Not a problem, I responded. I had grown up on a low cholesterol diet and only took a ten year break during marriage as I tried to perfect my cooking skills. So I have to inventive without saturated fat? Though I may miss my daily treat of a latte with semi-skimmed milk!
So what is cholesterol? And what is a healthy level? All humans need some cholesterol to make hormones, vitamin D, and substances that help you digest foods. Your body makes all the cholesterol it needs. Cholesterol travels through your bloodstream in small packages called lipoproteins. Two kinds of lipoproteins carry cholesterol throughout your body: low-density lipoproteins (LDL) and high-density lipoproteins (HDL). To be healthy, you need to have your LDL and HDL cholesterol in balance. LDL is sometimes called the bad 'cholesterol' as can build up on the walls of your arteries and increase the chances of getting heart disease. The lower your LDL cholesterol number, the better it is for your health. LDL cholesterol should be 3mmol/L or lower. HDL cholesterol protects against heart disease by taking the "bad" cholesterol out of your blood and keeping it from building up in your arteries. It carries cholesterol from other parts of your body back to your liver. Your liver removes the cholesterol from your body.A higher number for this cholesterol is a good sign i.e. anything above 1 mmol/L. In the UK, a total cholesterol level should be 5.0 millimoles per litre (mmol/L) or lower. The average in the UK is around 5.5 mmol/l for men and 5.6 mmol/l for women. Another cholesterol related products are lipid components called Triglycerides. Triglycerides are the fats carried in the blood from the food we eat. Excess calories, alcohol or sugar in the body are converted into triglycerides and stored in fat cells throughout the body. Triglyceride level should be under 1.7 mmol/L. If you have high total cholesterol levels (i.e. >6 mmol/l), you are at a greater risk of heart disease, hence the need to lower the levels in your blood.
It is important to note that blood cholesterol levels (known as Hypercholesterolaemia), is not a disease itself but a metabolic derangement that often contributes to many diseases, notably cardiovascular disease. In most cases, elevated cholesterol levels are associated with high-fat diet, especially saturated fat, coupled with an inactive lifestyle. Less commonly, raised cholesterol is genetic. (Most times a 'family history' of cholesterol could simply mean that the family has a shared lifestyle and diet rather than it being an inherited biological trait). Some people with high cholesterol who are otherwise healthy can live a long life without having a heart attack or getting heart disease. The risk of having a heart attack depends upon the combination of having high total cholesterol level with two or more other risk factors such as smoking, high blood pressure, low HDL cholesterol, family history of early heart disease and age(greater risk in men aged 45 and older, women 55 years and older). The USA National Heart, Lung and Blood Institute have a quick risk calculator. Overall, reducing your cholesterol through diet reduces your lifetime risk of heart disease or stroke by 17% Cochrane Review . If you're told you have high cholesterol, you need to take steps and seek treatment to lower your LDL cholesterol. The typical prescription is "therapeutic life change to good diet, exercise and weight management". Sometimes drug treatment is given but only as an addition to diet.
So does diet really work? Systematic reviews have shown that special cholesterol-lowering diets do lower LDL cholesterol in children and adults from families with a history of high cholesterol. By simply reducing your saturated fat intake, you can reduce the serum level in your blood and thereby reduce your risk of heart disease, attacks and need for heart surgery. This can be done by modifying the fat in our food by replacing some saturated fat with plant oils and unsaturated spreads. However it is unclear whether monounsaturated or polyunsaturated fats are more beneficial. Modifying the fat you eat seems will be more effective and beneficial if you do so for at least two years. Studies and trials have shown that those at increased risk of cardiovascular disease (e.g. people with hypertension, cholesterol or diabetes) and people who already have heart disease really do benefit (though it is suggested that healthy people should do it too to prevent high blood cholesterol in the first place).
By making changes to a high fibre diet with lots of fruit and vegetables, reduced alcohol intake with low saturated fat and transfats, you can make a difference. A simple acronym I use to remember the components of a healthy diet is FEASTS - Fruit & Veg, Exercise and reduce Alcohol, Salt, Trans-fats and Sugar. Nothing new! Just tried and tested! And it doesn't have to be boring - there are a number of cookbooks out there that are low in fat (be careful of some 'sugar-free' cookbooks that swap the sugar for fat and vice versa) and you can still cook with oil as apart from coconut oil and palm oil, cooking oils like olive oil, rapeseed, grapeseed, canola and vegetable oils are fine, bearing in mind you're using them sparingly and try to use the lighter versions where possible. (A cook non-stick frying pan and oven dish helps!) The Portfolio diet is perhaps the most well known of the eating plans for lowering cholesterol and has been shown to reduce cholesterol by at least 10% in 6 months but there are others on the web and Boots website offers good advice on cholesterol management as does Heart UK which includes a Mediterranean diet and tips for Christmas.
And what about eggs? And nuts? Some animal products such as eggs, shellfish and liver contain high levels of cholesterol however, high cholesterol containing foods have not been shown to increase the levels of LDL cholesterol in humans unless they also contain high levels of saturated fat. So in short, focus on cutting out the saturated and trans-fats such as pastry, fast foods, cookies and limit processed meats. My jury is still out on nuts. Whilst they are low in saturated fat, they are still high in fat and calories and if roasted or salted, contain high levels of salt. So perhaps keep them in moderation.
Last question - so how low should you go and how long does it take? There seems to be an array of different opinions on this across the web. Having low cholesterol is also bad for you as we need cholesterol for production of vitamins such as vitamin D and it has a role to play in our immune system. There's also a link between having healthy levels of cholesterol and being happy. I'd stick with what evidence we have even if it is largely focused on people who have high LDL and other risk factors, it seems that you need to stick to your diet long term (at least over 2 years) and depending on how dramatic your diet and lifestyle change is, you should see your LDL cholesterol dropping within the first 3-6 months. Have your levels monitored regularly.