Many people avoid eating avocados because of their fat or calorie content and worries about weight gain. In fact, avocados are good for weight loss as studies show they fill you up and reduce appetite so you eat less overall. Avocados are also an excellent source of antioxidants and beneficial monounsaturated fats that help to lower cholesterol and blood pressure, as well as improving glucose control in diabetes.
The avocado, or alligator pear is mostly used as a vegetable but is, in fact, a fruit. Some avocados are naturally small and round, while others are ovoid and can weigh as much as one kilogram.
Unlike most other fruit, except olives, avocados are low in sugar and rich in oils. As much as 30% of avocado pulp consists of oil, of which 70% to 80% are beneficial monounsaturates similar to those found in olive oil.
Avocados are low in sodium and provide potassium and magnesium which have blood pressure lowering actions. Avocados also provide antioxidant polyphenols and carotenoids. As well as providing carotenoids such as lutein, avocados enhance the absorption of carotenoids in other salad foods eaten at the same time. Adding chopped avocado or avocado oil to salsa, for example, boosts the absorption of tomato antioxidants (lycopene and betacarotene) four fold compared with an avocado-free salsa.
Although avocados have a high energy content, they also have one of the highest protein content of any fruit.
To avoid hand injuries, used a plastic knife to prepare your avocado, or a fan cutter to slice the flesh.
Avocado and weight loss
Many people avoid eating avocados because of their high fat and calorie content. Dietary surveys in the US, for example, show that only 2% of people ate avocados. Yet those who eat avocado tend to have a lower weight than those who don’t eat them (78kg versus 81kg), a lower body mass index (26.7 versus 28.4) and lower waist circumference (93cm versus 97cm). They also had higher levels of ‘good’ HDL cholesterol and were less likely to have high blood pressure and poor glucose control.
The main sugar found in avocado is a unique form known as D-mannopheptulose which does not act like a conventional sugar. Instead, it blocks an enzyme (hexokinase) involved in glucose metabolism. Partly as a result, eating avocado helps to satisfy sensations of hunger and supports improved blood glucose control and weight management.
Together with their protein content, avocados are particularly filling so you tend to eat less overall.
In a study involving 26 people who were overweight, eating half an avocado with lunch significantly reduced hunger and desire to eat. As a result, those who had avocado with lunch ate less for the rest of the day than those eating the same number of calories at lunchtime, but without avocado.
Studies also suggest that oleic acid, which is the main type of monounsaturated fat found in avocados, help to protect against abdominal fat accumulation and may help to treat and even protect against metabolic syndrome.
A type of avocado known as SlimCado has been developed which contains around half the fat and a third fewer calories than normal avocados. These are popular for their lower calorie value but have less flavour and a lower level of the beneficial monounsaturated fats of ‘full fat’ avocados. I know which I prefer!
If you are eating half an avocado, a range of devices are available to store the other half in the fridge that help stop the flesh from oxidising and turning black.
Avocado and healthy ageing
Fascinating research shows that the unique avocado sugar, mannoheptulose, appears to mimic the effects of caloric restriction to slow aging. Preliminary studies suggest that mannoheptulose extends lifespans in fruit flies by around 15% and by 30% in mice. Whether or not the same is true for humans remains to be seen!
Avocado oil has beneficial effects on energy within mitochondria by reducing the formation of free radicals. As poor mitochondrial function is common in ageing cells, this is under further investigation.
Avocado and skin protection
Skin shows the first visible signs of ageing and avocado pigments also appear to protect against UV damage. Avocado oil also contains hormone-like phytosterols that have a regenerative effect on ageing skin.
In one study, involving 82 airline pilots and frequent air travellers who are exposed to high levels of ionising radiation, those with high intakes of the antioxidant pigments found in avocados showed significantly less DNA damage than those with low intakes.
In a group of Japanese women, a higher intake of monounsaturates and carotenoid pigments such as those found in avocado was associated with better skin elasticity and fewer wrinkles.
Avocado and cholesterol levels
Avocados supply over 100mg phytosterols per 100g. These phytosterols block the absorption of cholesterol in the gut to help lower blood cholesterol levels. People who eat the most avocados have a better cholesterol balance, with higher ‘good’ HDL and lower ‘Bad’ LDL-cholesterol.
The results from ten studies show that eating avocado can significantly reduce total cholesterol, ‘bad’ non-HDL cholesterol and triglycerides to help reduce the risk of heart attack and stroke. Eating avocado regularly can reduce total cholesterol by 17%, LDL-cholesterol by 22%, triglycerides by 22% and increase ‘good’ HDL-cholesterol by 11%.
Avocados and avocado oil fit into healthy heart eating plans such as the DASH diet.
Avocado and diabetes
Avocado and its oil have beneficial effects that may protect against metabolic syndrome (prediabetes) and diabetes. Replacing a low-fat, complex-carbohydrate rich diet with an avocado-rich diet significantly improved blood glucose levels in people with type 2 diabetes.
Avocado and osteoarthritis
These avocado and soy supplements are not yet well known, but are worth trying if other approaches have not helped you arthritis hip or knee pain.
Avocado, eye and brain health
Avocado is a good source of the carotenoid pigment, lutein, which helps to protect against macular degeneration – one of the leading causes of reduced vision in later life. Lutein is also associated with better brain function and ability to think straight (cognition) in older people.
In a recent trial involving 40 healthy adults (average age 63 years), eating one avocado per day (weighing roughly 135g and providing 0.5mg lutein) for six months caused blood levels of lutein to increase by 25% compared to a control group not eating avocado. The level of macular pigment in their eyes increased and they showed improvements in concentration and sustained attention. The researchers suggests that dietary recommendations should include avocados to help improve brain cognitive health.
How to add avocado to your diet
Avocados only start to ripen and increase their nutritional value once they are cut from the tree. Store unripe avocados at room temperature until the flesh softens sufficiently to eat.
Avocado is often served as a starter with a dash of vinaigrette or mixed with prawns and a cocktail sauce. It can be mashed and spiced to make guacamole, served sliced in a salad, and even cooked in a vegetable and avocado bake.
Avocado oil can be used in cooking, or drizzled over salads and dips.
How to make REAL Avocado Guacamole
- 1 ripe avocado
- 1 lime
- 1/2 tomato (chopped in small pieces)
- 1 shallot onion, finely chopped
- Handful coriander leaves (cilantro) chopped
- Jalapeno pieces (optional)
- Freshly ground black pepper (to taste)
Smash the avocado flesh, then add the remaining ingredients together.