Introduction:
While many people are somewhat afraid of eating avocados because of their high fat content, research shows many health benefits are attributed to this wonderful fruit. In fact, in an exciting new study conducted at the University of Waterloo in Canada, a component of avocado was shown to possess significant action against acute myeloid leukemia.
Background Data:
Avocados are an excellent source of monounsaturated fatty acids, as well as potassium, vitamin E, B vitamins and fiber. One avocado will have the potassium content of 2-to-3 bananas (about 1,000 mg of potassium). Of course, an avocado will also have about 3 times the calories as a banana. A 3-1/2 ounce (100g) serving is about ½ of an avocado and provides 160 calories, 2.0 g protein, 14.7 g fat, 8.5 carbohydrate and 6.7 g fiber.
Avocado oil consists of 71% monounsaturated fatty acids (MUFA), 13% polyunsaturated fatty acids (PUFA), and 16% saturated fatty acids (SFA), which helps to promote healthy blood lipid profiles and enhance the bioavailability of fat-soluble vitamins and phytochemicals from the avocado or other fruits and vegetables. The consumption of avocados with salads or salsa increases the bioavailability of carotenoids multi-fold, which may add to the potential health benefits.
Avocados contain a moderate level of phytochemicals, especially polyphenols that show antioxidant activity. Avocados have the highest fruit antioxidant capacity in protecting against the formation of damaged fats (lipid peroxides) in the blood.
A total of eight clinical trials have shown consumption of avocados produce cardiovascular benefits including improvements in cholesterol levels. In subjects with high blood cholesterol levels, avocado enriched diets improved blood lipid profiles by lowering LDL-cholesterol and triglycerides and increasing HDL-cholesterol, compared to high carbohydrate diets or other diets without avocado.
Along with the benefits to cardiovascular health, several preliminary clinical studies indicate that avocados can support weight control. The calories of the avocado seem to be offset by the promotion of satiety. For example, in a randomized single blinded, crossover study of 26 healthy overweight adults when the subjects ate one-half an avocado at lunch they reported significantly reduced hunger and desire to eat, and increased satiation as compared to the control meal.
New Data:
Acute myeloid leukemia (AML) is a type of cancer in which the bone marrow makes abnormal stem cells of white blood cells, red blood cells, or platelets. It is the most common type of acute leukemia in adults. Treatment for acute myeloid leukemia (AML) currently involves chemotherapy regimens that only produce limited benefit to long-term survival.
Canadian researchers identified a compound in avocados, avocatin B, as a substance that causes selective toxicity to the abnormal cells in AML. Specifically, their research using functional cell assays showed that avocatin B reduced the viability of AML stem cells without effects on normal stem cells.
Their next step was explaining this observed effect by discovering the mechanism. What they discovered was that avocation B was toxic to the cancer cells of AML because it inhibited their mitochondria – the energy producing compartment of cells. It inhibited the ability of mitochondria in the leukemia stem cells to utilize fats as an energy source. Basically, the avocation B turned off the cancer cells leading to a process known as apoptosis – a type of cellular suicide.
What is exciting about this research is the selectivity of the avocatin B as it had no effect on normal cells. Although there is obviously a lot more research required before avocatin becomes a proven treatment for AML, this line of research is clearly encouraging.
Commentary:
I love reading these sorts of studies because it shows us the tremendous potential of food as medicine, even in serious health conditions like cancer. When I read a study like this one, it makes me realize that we have not even scratched the surface in understanding the healing power of food.
In addition to regularly eating a moderate amount of an avocado (no more than ½ per day), avocado oil can be used as cooking oil. It may turn out to be a healthy and economical alternative to olive oil. It has a higher smoke point than olive oil (500 degrees F vs. 400) and is also rich in antioxidant polyphenols.
Reference:
Lee EA, Angka L, Rota SG, et al. Targeting Mitochondria with Avocatin B Induces Selective Leukemia Cell Death. Cancer Res. 2015 Jun 15;75(12):2478-88.
Dr. Michael Murray
6/30/15
