Who can resist a piece of toast with a thick, buttery layer of avo, a tangy guacamole, or a salad with rich, succulent chunks of this creamy green fruit?
The avocado pear, a native of Mexico and Central America, is actually a berry with a single, large seed. Nowadays it is cultivated throughout the world in Mediterranean and tropical climates. Avos have a green skin, are usually pear-shaped and only ripen after harvesting.
It is certainly true that avocados have a high fat content – 75 to 80% of the calories come from fat – but conventional dieters don’t despair; only a small portion is saturated and the rest are healthy mono- and polyunsaturated fats. In fact, the avocado is the only fruit that contains a substantial amount of monounsaturated fat.
But it's oleic acid, the primary fat in avocados, that has been shown to offer significant protection against breast cancer - see below.
Can avocados really prevent or cure cancer?
It certainly looks promising. A report in the Journal of Nutritional Biochemistry stated that the carotenoids and tocopherols (chemical compounds which may have vitamin E activity) in avocado were shown to inhibit the growth of prostate cancer cell lines in an artificial environment (in vitro).
The study also showed that phytochemicals extracted from the avocado fruit inhibit and kill cancer cells, suggesting that the phytochemicals from avocado included in the diet may offer protection against cancer.
Researchers at Ohio State University in the US confirmed this. They found that extracts from Hass avocados kill or stop the growth of pre-cancerous cells that lead to oral cancer. They published their findings in the journal Seminars in Cancer Biology.
Lead author of the study, Steven M D'Ambrosio, who collaborated with researchers in Ohio State's College of Pharmacy, found that phytochemicals extracted from avocados target multiple signaling pathways and increase the amount of reactive oxygen within the cells, leading to cell death in pre-cancerous cell lines. But the phytochemicals did not harm normal cells.
Avos contain the following cancer-fighting phytochemicals and anti-oxidants:
- Carotenoids like alpha and beta carotenes and zeaxanthin. Avos contain 11 caretenoids and dietary carotenoids are thought to provide health benefits in decreasing the risk of disease, particularly certain cancers and eye disease. Foods high in beta-cryptoxanthin (a natural carotenoid pigment) protect cells from the damaging effects of free radicals and provide a good source of vitamin A. This carotenoid may also reduce the risk of lung cancer according to a study published in Cancer Epidemiology Biomarkers and Prevention. The 2004 study found beta-cryptoxanthin reduced lung cancer risk by more than 30 percent in those with diets providing the highest amounts.
- Vitamin E. There is some evidence to suggest that the antioxidant vitamin E in its natural form protects against cancer. The American Chemical Society describes avocados as awesome because of their high fibre content, potassium, vitamin B6, vitamin E and antioxidant properties. Half a Hass avocado has 1.3 milligrams of Vitamin E that explains avos' ability to minimise oxidative injury and fight free radicals - the oxygen molecules that can cause disease.
- Lutein, which is found in vegetables like broccoli, kale and spinach has been shown to lower breast cancer.
- Glutathione. High levels of glutathione, the body’s master antioxidant, enable the liver to detoxify the body and protect it against oxidative stress.
- Oleic acid. Avocados are a rich source of oleic acid, which is has been proven to have a protective effect against breast cancer. (Oleic acid is also important because all the above phytochemicals need a certain amount of healthy fat for optimal absorption.) A study published in the AU Journal of Technology showed that women eating a diet rich in oleic acid have shown decreased rates of breast cancer.
But that's not all ...
A study by Shizuoka University in Japan found that avocados also protect against liver damage caused by the hepatitis viruses while other studies have shown that avocados may have a positive effect on hypertension and blood sugar levels. An American study published in the Journal of the American Heart Association has also shown it can lower bad cholesterol (or low-density lipoprotein (LDL)) levels.
Image: Avocado pears from Shutterstock