Avocados and cholesterol

Humans have a long history of strange beliefs. The Romans believed that epilepsy could be cured by drinking gladiator blood. The Stone Age cure for a headache was to drill a hole into your skull (presumably having someone drilling into your skull with a sharpened flint put the headache pain into perspective). As the Black Death swept Europe and England a belief became widespread that the only way to cure the sores was to pluck a live chicken and strap its bottom to the sore (an alarming development for the chicken population that had some interesting fashion outcomes). In the 21st century humans somehow believed that “reality television” had something to do with reality and that renovating a toilet was worthy of a camera being present (a belief derided in future centuries as reflecting where the creativity of the species had gone).

It is easy of course to retrospectively cast stones and snigger at earlier beliefs. We may for instance have a little smirk at the Aztec belief that virginal girls should not walk through the avocado orchards at harvest time as the avocados alarmingly resembled human testicles. These days of course most people wouldn’t know where to find an avocado orchard, or other parts of the equation for that matter (although the locavore food movement may be changing the orchard part of things). Safely ensconced in our iFad mentalities modern humans laugh smugly at such metaphoric thinking as shaped the Aztec attitude to avocados. We 21st century folk think we know all about the reality of things because we can analyse them and break them down. Yet the nature of “science” is that it keeps making itself redundant and what you thought you knew about avocados may be revolutionised, or at least updated, by a new study indicating that avocadoes can lower your cholesterol.

This may surprise you a little as avocados are creamy to the taste but it is monounsaturated fat that yields this sensation. In fact, over half of the total fat in avocado is provided in the form of oleic acid, which helps your digestive tract form transport molecules for fat that can increase your absorption of fat-soluble nutrients like carotenoids. Avocado also contains lots of carotenoids like betacarotene as well as vitamin E and phytosterols.

In the new study healthy participants aged 21-70 who were either overweight or obese were divided into three groups. One group went on a low fat diet without avocado, a second group went on a moderate fat diet without avocado and a third group went on a moderate fat diet with avocado. In both of the moderate fat groups 17 per cent of fats were monounsaturated fats although of course, only the avocado group had them from avocado. The low fat group had less fat overall and 11 per cent of fats in their diet were monounsaturated. After five weeks the researchers took blood samples to see what effect the diets had on their cholesterol levels compared to before they started the study.

The results showed that the moderate fat diet without avocado lowered bad LDL cholesterol by 0.2 mmol/litre, the low fat diet without cholesterol lowered it by 0.22 mmol/litre, and the moderate fat diet with avocado lowered LDL by 0.35 mmol/litre.

It is noted by the researchers that the research was supported by the Haas Avocado Board but they assert that no intervention beyond funding took place and they admit that this was a controlled situation and does not necessarily reflect real-world eating. However, the fact that a moderate fat diet with the same amount of monounsaturated fat was so significantly different to a moderate fat diet with avocado in its effects suggests that there is something about the whole avocado that has beneficial effects on cholesterol.

Not only is it safe to go into the avocado orchard, it’s probably a very good idea.