Controlling cholesterol through diet
Lifestyle measures to control cholesterol levels are generally the first port of call in managing elevated blood lipids. But best-practice advice in this area has changed over time and sometimes myths about what foods to eat, and which to watch, stubbornly refuse to be dispatched.
So what type of dietary change should you advise someone wanting to better manage their blood cholesterol levels? It’s not complicated, as long as you first follow Rule 1: The low-fat diet is dead; the science has moved on.
Include healthy fats such as avocado
A recent blog [link to Healthy Fats blog] covered the many health reasons, including a reduced risk of heart disease, for ditching the low-fat mantra and embracing healthy unsaturated fats. In a nutshell, healthy unsaturated fats, improve blood cholesterol levels by increasing the amount of HDL, while reducing saturated fat reduces LDL cholesterol.1-3
The new Dietary Guidelines for Australians4, has also shifted the focus from reducing all fats to encouraging replacing saturated fats with unsaturated fats, with Guideline 3 stating:
Replace high fat foods which contain predominantly saturated fats such as butter, cream, cooking margarine, coconut and palm oil with foods which contain predominantly polyunsaturated and monounsaturated fats such as oils, spreads, nut butters/pastes and avocado.
The research specifically into the cholesterol lowering properties of avocado, to date suggests that regular avocado consumption consistently leads to a reduction in cholesterol when consumed in an energy controlled diet.5-8
So the first group of foods to focus on when considering a diet pattern for cholesterol control is ensuring foods that provide healthy fats feature, and those that contain saturated fats are reduced. Unsaturated fats fall into two groups, monounsaturates and polyunsaturates. All fat-containing foods contain a mix of fat types, but usually one type predominates.
Practical advice: Include a serve of healthy fat at each meal; 1/4 avocado in a salad, sandwich or on toast, a handful of nuts or seeds, a dash of olive oil or unsaturated vegetable oil such as canola, sunflower or safflower.
Include a handful of nuts
Around 67g of nuts per day can reduce cholesterol by around 5%.9 This may help explain why eating at least 30g of nuts on most days every week can reduce the risk of developing heart disease by 30-50%.10 Nuts also contain a range of bioactive phytochemicals, which result in a greater reduction in cholesterol levels than might be expected simply due to their healthy fats.11
Practical advice: Include a 30g handful of nuts each day.
Include plenty of fibre-foods
There are two types of fibre in foods: insoluble fibre that important for bowel health and regularity12 and soluble fibre that can help reduce cholesterol reabsorption in the gut13. Both fibres are important in heart health.14 Dietary fibre is found in wholegrains, legumes, nuts, fruit, vegetables, including avocados and soluble fibre is high in oats and legumes.
Practical advice: Include at least 2 serves of fruit and 5 serves of vegetables each day. Base every meal on vegetables and wholegrains. A quarter of an avocado (50g) has around 2g of heart-healthy fibre, and almost 20% of an adult’s overall dietary fibre needs. Porridge and legumes at least once a day will also boost both types of fibre.
Include foods containing plant sterols
Plant sterols are phytochemicals with a similar chemical structure to cholesterol, but which can’t be absorbed by the body.15 This interferes with the cholesterol absorption and reabsorption systems resulting in higher cholesterol excretion. Nuts, legumes, and grains are a natural sources of plant sterols. However, a number of foods are enriched with higher levels, for example, plant-sterol margarine spreads, milk, cheese and yoghurts. A daily intake of 2–3 g plant sterols have been shown to lower blood cholesterol levels by up to 10% depending on the age16. This is generally around 25g or 1 tablespoon of plant sterol margarine.
Practical advice: Include natural sources of plant sterols, such as nuts, legumes and wholegrains; including a plant-sterol enriched margarine or dairy product at the serving sizes and frequency recommended on the label will ensure a daily intake at the levels known to be effective.
Include soy foods
Soy beans contain soy protein and soluble fibre, both found to help lower cholesterol. A meta analysis concluded that one to two serves of soy protein foods a day (15 to 30g soy protein) reduces LDL cholesterol by 6-7%, and increased HDL cholesterol by around 3%.17
Practical advice: Include soy in the diet in a variety of ways: in staples such as soy and linseed bread, soy pasta, and soy milk or in traditional Asian foods such as miso soup and tofu.
Include fish regularly
Oily fish such as tuna, salmon, sardine and mackerel are good sources of omega 3 fats. Consuming 400g of oily fish per week has been shown to improve biomarkers of heart disease18,19 and the Heart Foundation recommends eating 2-3 serves per week16.
Practical advice: Encourage oily fish from sustainable sources at least twice a week.
Adding it all up...
The best news is that one review20 concluded that combining multiple dietary changes resulted in a cumulative effect, with improvements in cholesterol from making two or more changes, such as those covered above, additive. However even if just a few strategies are suggested and incorporated long-term will make a difference.
Practical advice: Choose two that are achievable for your client and start there. Once they’ve got those under their belt, you can more on to encourage even more improvements.
1. Willett WC. Dietary fats and coronary heart disease (review). Intern Med. 2012; 272: 13-24.
2. Mensink RP, Zock PL, Kester AD, Katan MB. Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. Am J Clin Nutr. 2003;77(5):1146-55.
3. Denke MA. Dietary fats, fatty acids, and their effects on lipoproteins. Curr Atheroscler Rep. 2006;8(6):466–471.
4. National Health and Medical Research Council (2013) Australian Dietary Guidelines. Canberra: National Health and Medical Research Council.
8. Colquhoun DM, et al. Comparison of the effects on lipoproteins and apolipoproteins of a diet high in monounsaturated fatty acids, enriched with avocado, and a high-carbohydrate diet. Am J Clin Nutr. 1992;56(4):671-7.
10. Hu FB, Stampfer MJ. Nut consumption and risk of coronary heart disease: a review of epidemiologic evidence. Curr Atheroscler Rep. 1999;1(3):204-9.
11. Kris-Etherton PM et al. Nuts and their bioactive constituents: effects on serum lipids and other factors that affect disease risk. Am J Clin Nutr 1999;70(suppl):504S–511S.
12. Australian Government NHMRC. Nutrient Reference Values. Fibre paper. Accessed at http://www.nrv.gov.au/nutrients/dietary%20fibre.htm; 12 June 2013.
13. National Heart Foundation of Australia. Position Statement: Carbohydrates, dietary fibre, glycaemic index/load and cardiovascular disease, Questions and Answers ,Health Professionals. February 2006. Accessed at http://www.heartfoundation.org.au/information-for-professionals/food-professionals/Pages/guides-policies-position-statement.aspx; 12 June 2013.
15. National Heart Foundation 2009 Position Statement on Phytosterol/stanol enriched foods, (updated 2009), including Q & A for Professionals; accessed at http://www.heartfoundation.org.au/SiteCollectionDocuments/Stanol-enriched-foods-position-statement.pdf
16. Heart Foundation of Australia. Position statement. Dietary fats and dietary sterols for cardiovascular health 2009, http://www.heartfoundation.org.au/SiteCollectionDocuments/Dietary-fats-position-statement-LR.pdf; 12 June 2013.
17. Anderson JW Bush HM. Soy protein effects on serum lipoproteins: a quality assessment and meta-analysis of randomized, controlled studies. J Am Coll Nutr. 2011;30(2):79-91
20. Harland JI. Food combinations for cholesterol lowering. Nutr Res Rev. 2012;25(2):249-66.