Do you love avocado? Dr Karen Bridgman shares the health benefits of the fruit

The avocado pear (alligator pear) is a fruit native to Central Mexico. From the most ancient evidence of an avocado pit 10,000 years ago, the avocado today is the fourth most important tropical fruit in the world, cultivated widely in tropical and Mediterranean climates. The fruit is fleshy with a single large seed and can be pear shaped, spherical or egg shaped. The fruit matures on the tree but ripens about a week after harvesting (similar to bananas to which it is related botanically). Avocado is a member of the Lauraceae family, and related to cinnamon, bay and sassafras.

Body weight, BMI and waist circumference were significantly lower and HDL (the good cholesterol) was higher in avocado consumers.

Avocado is rich in B vitamins (high in B5, B6 and folic acid), vitamins E and K, has more than twice the potassium of bananas, high soluble and insoluble dietary fibre of 8.6 gms /100 gms (higher than apples), while being low in sugars/carbohydrates.

Avocado has the second highest oil content of all known fruits (olive is higher) and these oils/fats are healthy fats. As the fruit ripens the saturated fats decrease and the monounsaturated fats (MUFAs) increase. About 75 per cent of the energy of avocado comes from the MUFAs — omega-9 oleic acid (high in olive oil). Avocado oil also contains linoleic acid and palmitic acid with saturated fat being about 14 per cent. Overall the ratio of fats is omega-3 — 1 per cent, omega-6 — 14 per cent, omega-9 — 71 per cent and saturated fats — 14 per cent. These ratios enhance the bioavailability of fat-soluble vitamins and phytochemicals from the avocado as well as those in other fruits and vegetables consumed in the same meal.

Avocado fruit also contains active ingredients such as phytosterols, and carotenoids (lutein and zeaxanthin). These give the fruit its green colour. Antioxidant procyanidins and phenolic compounds are present (and particularly high in the seeds).

Avocados have many culinary uses as they can be used in savoury or sweet dishes. Having a high smoke point, avocado oil is useful for cooking.

Therapeutic uses

Endocrine system

Avocado reduces the risks of metabolic syndrome and type-2 diabetes. In clinical trials, avocado consumption was associated with a 50 per cent reduced risk of metabolic syndrome, but these trials showed that avocado consumption was associated with improved diet quality and increased nutrient intake overall, as those who consumed avocados were also more likely to have significantly higher intakes of vegetables and fruit. Body weight, BMI and waist circumference were significantly lower and HDL (the good cholesterol) was higher in avocado consumers.

Cardiovascular

With its ability to improve the ratios of healthy fats, and its antioxidants, avocado consumption improves cardiovascular health. The high level of beta-sitosterol particularly (roughly 57 mg in half an avocado), inhibits cholesterol absorption and decreases its synthesis, resulting in lowered cholesterol levels overall.

The high potassium levels help maintain electrolyte balance, which is important for the electrical regulation of the heart, regulating blood pressure and reducing fluid retention. And along with improving cholesterol levels, avocado has been shown to be anti-obesity, anti-thrombotic, anti-atherosclerotic and anti-diabetic, which are all cardioprotective properties.

Weight management

In a clinical trial, an adult cohort was tested for avocado consumption and changes in weight. Surprisingly avocado is known to reduce the risk of becoming overweight. The results showed that habitual consumption of avocados (more than 32g per day — one avocado weighs 120-150g) helped reduce weight gain. The avocado consumers gained significantly less weight than non-consumers. However if you are trying to lose weight, it is best to restrict your avocado intake to half to one per day.

Longevity, skin and eye health

The lutein and zeaxanthin in avocado have been shown to decrease the progression of macular degeneration, cataracts and cartilage deterioration that often occur with ageing. The carotenoids protect the skin from oxidation and inflammation that is related to sun damage as well as help reduce scarring.

Topical use of avocado oil promotes collagen synthesis and aids in wound healing and skin disorders, including psoriasis.

Avocado leaves and seeds

The leaves of the avocado tree are often used as a spice.

Research shows that avocado seed improves symptoms of hypertension, inflammatory conditions and high cholesterol. It has shown protective effects on pancreatic cells, stimulating insulin production and lowers blood glucose by up to 73 per cent (in diabetic rats).

The leaves and seeds of the avocado have been used in traditional medicine to manage conditions like memory loss and Alzheimer’s disease, conditions associated with the acetylcholinesterase enzymes. Avocado seed extract was the most effective at inhibiting these enzymes and accompanied with a strong antioxidant effect showed potential for future research.

Avocado seed extract was shown to induce apoptosis in human breast cancer cells. It has also been found useful to improve the outcomes in prostate cancer.

Cautions and contraindications

Latex allergies

It is estimated that one in six people are allergic to latex. Half of these people with latex allergies also react to avocado, banana, chestnut, kiwifruit, passionfruit, plum, strawberry and tomato. This is because the proteins present in latex are also present in these fruits.

Avocados, along with soy, tomatoes, spinach and pumpkin are naturally high in histamines so would need to be avoided if high histamine is a health problem.