New meta analysis – avocados reduce blood lipids
A new paper published in the Journal of Clinical Lipidology in February 2016(1) conducted a meta analysis of 10 randomised control trials that tested the effect of diets containing avocado on participants’: total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides.
The researchers from the University of the Pacific California USA found that from a combined 229 study participants avocado consumption lead to significantly reduced:
- total cholesterol by 0.49mmol/L
- LDL cholesterol by 0.43mmol/L
- Triglycerides by 0.70mmol/L and
- HDL cholesterol was also reduced by a non significant 0.005mmol/L.
Those participants with high blood cholesterol to begin with had greater reductions in total cholesterol and LDL cholesterol as expected. Those who are overweight or had diabetes did not have significant reductions however it may have been the small number of participants in these subgroups which affected the analysis.
Researchers founds swapping avocado for saturated fats had the greatest benefits than adding avocado to an existing diet.
It’s also possible weight loss may have impacted these results since weight loss can reduce blood lipids. Six of the 10 studies measured weight before and after an avocado enriched diet over 2 to 6 weeks. Body weight decreased in all six studies but was statistically significant in only three. If nothing else it does show that avocado can be included in diets and still result in weight loss.
Of the 10 studies three lasted less than four weeks and seven over four weeks in duration.
The amount of avocado eaten varied from 136g to 300g of avocado a day. This is equivalent to the edible portion of 1-2 small Australian avocados a day. Further work is needed to determine the exact amount of avocado that has the greatest effect on each blood lipid.
Since cholesterol is a risk factor for heart disease larger trials studying the impact of avocado on cardiovascular events is warranted.
In Australia Cardiovascular disease (CVD) is a major cause of death in Australia, with 43,603 deaths attributed to CVD in Australia in 2013. Cardiovascular disease kills one Australian every 12 minutes. For Coronary heart disease specifically it is the single leading cause of death in Australia killing one Australian every 27 minutes. Around 1.4 million Australians are affected by heart disease and in 2011/12, one third of adult Australians aged 18 years and over had measured high cholesterol representing 5.6 million adult Australians.(2)
It is well established that diets high in monounsaturated fats (MUFAs) can reduce heart disease risk. For instance increasing MUFAs in the diet by 5% can read to a 19% reduction in risk of heart disease.(3)
Avocados are rich in MUFAs - on average they contain 13% total fat of which 50% is MUFAs. Avocados also contain other heart healthy nutrients: vitamin C and E, potassium, fibre, antioxidants and plant sterols.(4)
Looking for ways to include more avocado in your diet or the diets of your clients?
Avocado Australia has recipes here http://avocado.org.au/recipes or browse for avocado recipes on the Dietitians Association of Australia website