26 Scientific Studies on Avocado



Native to South America and the Caribbean, the avocado tree produces a fruit that is actually a large egg-shaped berry with a sizable seed at its center. Its use among pre-Incan and other ancient Mesoamerican cultures has been dated to about ten thousand years ago by archaeologists. The Aztecs considered avocado to be a fertility booster.

Though dozens of avocado cultivars are harvested, the Hass cultivar accounts for three-fourths of all avocados consumed. Mexico remains by far the biggest producer. Avocados contain much more potassium than bananas, are high in monounsaturated fats and B vitamins, and have a high fiber content. They have proven health benefits in many areas, particularly in lowering levels of harmful LDL and triglycerides and raising levels of beneficial HDL.


AV119, a Natural Sugar from Avocado gratissims, Modulates the LPS-Induced Proinflammatory Response in Human Keratinocytes. Donnarumma G, Paoletti I, Buommino E, Et al. Inflammation. 2010 Oct 9 (Epub ahead of print). Key Finding: “Our data show that AV119, a patented blend of avocado sugars, is able to modulate significantly the proinflammatory response in human keratinocytes, blocking the NF-kB activation in human keratinocytes.”


Hypoglycemia and hypocholesterolemic potential of Persea Americana leaf extracts. Brai BI, Odetola AA, Agomo PU. J Med Food. 2007 Jun;10(2):356-60. Key Finding: “These results suggest that aqueous and methanolic leaf extracts of P. Americana (avocado) lower plasma glucose and influence lipid metabolism in hypercholesterolemic rats with consequent lowering of T-CHOL and LDL-CHOL, and a restoration of HDL-CHOL levels. This could represent a protective mechanism against the development of atherosclerosis.

Cancer (oral; prostate)

Selective induction of apoptosis of human oral cancer cell lines by avocado extracts via a ROS-mediated mechanism. Ding H, Han C, Guo D, Chin YW, Ding Y, Kinghorn AD, D’Ambrosio SM. Nutr Cancer. 2009;61(3):348-56. Key Finding: “Avocados have a high content of phytochemicals with potential chemo preventive activity. Previously we reported that phytochemicals extracted from avocado meat selectively induced apoptosis in cancer but not normal, human oral epithelial cell lines. In the present study, we observed that treatment of human oral cancer cell lines containing high levels of reactive oxygen (ROS) with D003 increased ROS levels twofold to threefold and induced apoptosis. These data suggest that perturbing the ROS levels in human oral cancer cell lines may be a key factor in selective apoptosis and molecular targeting for chemoprevention by photochemical.”

Chemoproventive characteristics of avocado fruit. Ding H, Chin YW, Kinghorn AD, D’Ambrosio SM. Semin Cancer Biol. 2007 Oct;17(5):386-94. Key Finding: “Our recent studies indicate that phytochemicals extracted with chloroform from avocado fruits target multiple signaling pathways and increase intracellular reactive oxygen leading to apoptosis. This review summarizes the reported phytochemicals in avocado fruit and discusses their molecular mechanisms and targets. These studies suggest that individual and combinations of phytochemicals from the avocado fruit may offer an advantageous dietary strategy in cancer prevention.”

Inhibition of prostate cancer cell growth by an avocado extract: role of lipid-soluble bioactive substances. Lu QY, Arteaga JR, Zhang Q, Huerta S, Go VL, Heber D. J Nutr Biochem. 2005 Jan;16(1):23-30. Key Finding: “Avocado contains numerous bioactive carotenoids. Because the avocado also contains a significant amount of monounsaturated fat, these bioactive carotenoids are likely to be absorbed into the bloodstream, where in combination with other diet-derived phytochemicals they may contribute to the significant cancer risk reduction associated with a diet of fruits and vegetables.”

An avocado constituent, persenone A, suppresses expression of inducible forms of nitric oxide synthase and cyclooxygenase in macrophages, and hydrogen peroxide generation in mouse skin. Kim OK, Murakami A, Takahashi D, Nakamura Y, Torikai K, Kim HW, Ohigashi H. Biosci Biotechnol Biochem. 2000 Nov;64(11):2504-7. Key Finding: “This study suggests that persenone A, an avocado constituent, is a possible agent to prevent inflammation-associated diseases including cancer.”

Cholesterol (and Hypercholesterolemia)

High-density lipoproteins (HDL) size and composition are modified in the rat by a diet supplemented with “Hass” avocado (Persea Americana Miller). Perez-Mendez O, Garcia Hernandez L. Arch Cardiol Mex. (Spanish). 2007 Jan-Mar;77(1):17-24. Key Finding: “The inclusion of avocado in the diet decreased plasma triglycerides increased HDL-cholesterol plasma levels and modified HDL structure. The latter effect may enhance the antiatherogenic properties of HDL.”

Effects of a vegetarian diet vs. a vegetarian diet enriched with avocado in hypercholesterolemic patients. Carrznza-Madrigal J, Herrera-Abarca JE, Alvizouri-Munoz M, Alvarado-Jimenez MR, Chavez-Carbajal F. Arch Med Res. 1997 Winter;28(4):537-41. Key Finding: “All three diets reduced HDL levels. To obtain beneficial effects on lipid profile with avocado, lower amounts of carbohydrates and polyunsaturated fatty acids are probably needed.”

Monounsaturated fatty acid (avocado) rich diet for mild hypercholesterolemia. Lopez LR, Frati Munari AC, Hernandez Dominguez BC, Cervantes MS, Hernandez Luna MH, Juarez C, Moran LS. Arch Med Res. 1996 Winter;27(4):519-23. Key Finding: “High lipid, high MFA-avocado enriched diet can improve lipid profile in healthy and especially in mild hypercholesterolemic patients, even if hypertriglyceridemia (combined hyperlipidemia) is present.”

Effects of avocado on the level of blood lipids in patients with phenotype II and IV dyslipidemias. Carranza J, Alvizouri M, Alvarado MR, Chavez F, Gomez M, Herrera JE. Arch Inst Cardio Mex. (Spanish). 1995 Jul-Aug;65(4):342-8. Key Finding: “Avocado is an excellent source of monounsaturated fatty acids in diets designed to treat hypercholesterolemia with some advantages over low-fat diets with a greater amount of carbohydrates.”

Carotenoid absorption from salad and salsa by humans is enhanced by the addition of avocado or avocado oil. Unlu NZ, Bohn T, Clinton SK, Schwartz SJ. J Nutr. 2005 Mar;135(3):431-6. Key Finding: “Adding avocado fruit can significantly enhance carotenoid absorption from salad and salsa, which is attributed primarily to the lipids present in avocado.”


Cardiovascular effects of Persea Americana Mill (Lauraceae) (avocado) aqueous leaf extract in experimental animals. Ojewole JA, Kamadyaapa DR, Gondwe MM, Moodley K, Musabayane CT. Cardiovasc J Afr. 2007 Mar-Apr;18(2):69-76. Key Finding: “The findings of this study tend to suggest that P. Americana leaf could be used as a natural supplementary remedy in essential hypertension and certain cases of cardiac dysfunctions.”

Effect of an avocado oil-rich diet over an angiotensin II-induced blood pressure response. Salazar MJ, El Hafidi M, Pastelin G, Ramirez-Ortega MC, Sanchez-Mendoza MA. J Ethnopharmacol. 2005 Apr 26;98(3):335-8. Key Finding: “Avocado oil-rich diet modifies the fatty acid content in cardiac and renal membranes in a tissue-specific manner. Diet content can be a key factor in vascular responses.”


A potential role for avocado and soybean based nutritional supplements in the management of osteoarthritis: a review. Dinubile NA. Phys Sportsmed. 2010 Jun;38(2):71-81. Key Finding: “Basic scientific research studies and a systematic review and meta-analysis of the available high-quality randomized clinical trials indicate that 300 mg of avocado and soybean unsaponifiables per day (with or without glucosamine and chondroitin sulfate) appears to be beneficial for patients with hip or knee osteoarthritis.”

Symptomatic efficacy of avocado-soybean unsaponifiables (ASU) in osteoarthritis (OA) patients: a meta-analysis of randomized controlled trials. Christensen R, Bartels EM, Astrup A, Bliddal H. Osteoarthritis Cartilage. 2008 Apr;16(4):399-408. Key Finding: “Based on the available evidence, patients may be recommended to give avocado/soybean unsaponifiables a chance for e.g., 3 months. Meta-analysis data support better chances of success in patients with knee OA than in those with hip OA.”

Avocado/soybean unsaponifiables in the treatment of knee and hip osteoarthritis. Angermann P. Ugeskr Laeger (Danish). 2005 Aug 15;167(33):3023-5. Key Finding: “These studies indicate that ASU has an effect on the symptoms of knee and hip osteoarthritis but not on the structural changes caused by osteoarthritis.”

Avocado-soybean unsaponifiables (ASU) for osteoarthritis—a systematic review. Ernst E. Clin Rheumatol. 2003 Oct;22(4-5):285-8. Key Finding: “The majority of rigorous trial data available to date suggest that avocado/soybean unsaponifiables is effective for the symptomatic treatment of osteoarthritis.”

Structural effect of avocado/soybean unsaponifiables on joint space loss in osteoarthritis of the hip. Lequesne M, Maheu E, Cadet C, Dreiser RL. Arthritis Rheum. 2002 Feb;47(1):50-8. Key Finding: “Avocado/soybean unsaponifiables significantly reduced the progression of joint space loss as compared with placebo in the subgroup of patients with advanced joint space narrowing.”

Symptoms modifying effect of avocado/soybean unsaponifiables (ASU) in knee osteoarthritis. A double-blind, prospective, placebo-controlled study. Appelboom T, Schuermans J, Verbruggen G, Henrotin Y, Reginster JY. Scand J Rheumatol. 2001;30(4):242-7. Key Finding: “The efficacy of ASU at a dosage of 300mg/day and 600mg/day was consistently superior to that of placebo at all endpoints, with no differences observed between the two doses.”

Modification of articular cartilage and subchondral bone pathology in an ovine meniscetomy model of osteoarthritis by avocado and soya unsaponifiables (ASU). Cake MA, Read RA, Guillou B, Ghosh P. Osteoarthritis Cartilage. 2000 Nov;8(6):404-11. Key Finding: “These findings support other studies which have proposed that avocado and soya unsaponifiables may exhibit disease-modifying anti-osteoarthritis activity.”

The possible ‘chondroprotective’ effect of the unsaponifiable constituents of avocado and soya in vivo. Khayyal MT, el-Ghazaly MA. Drugs Exp Clin Res. 1998;24(1):41-50. Key Finding: “An experimental in vivo model for studying cartilage destruction has been used to study the possible chondroprotective effect of the unsaponifiable constituents of avocado, soya and their combination. The unsaponifiables of both avocado and soya significantly reduced the degenerative changes induced by the granuloma tissue on the implanted cartilage in control animals. The effect was even more marked when animals were treated with the combination of the two unsaponifiables at a 1:2 ratio.”

Efficacy and safety of avocado/soybean unsaponifiables in the treatment of symptomatic osteoarthritis of the knee and hip. A prospective, multicenter, three-month, randomized, double-blind, placebo-controlled trial. Blotman F, Maheu E, Wulwik A, Caspard H, Lopez A. Rev Rhum Engl Ed. 1997 Dec;64(12):825-34. Key Finding: “One of the objectives of symptomatic slow-acting drugs for osteoarthritis is to reduce the need for drugs with a less favorable safety profile, mainly analgesics and non-steroidal anti-inflammatory drugs. Avocado/soybean unsaponifiables reduced the need for these drugs in patients with primary femorotibial or hip osteoarthritis. The functional index showed a significantly greater improvement in the active (avocado/soybean) group.”


Vitamin B(12) cream containing avocado oil in the therapy of plaque psoriasis. Stucker M, Memmel U, Hoffmann M, Hartung J, Altmeyer P. Dermatology. 2001;203(2):141-7. Key Finding: “The results of this clinical trial provide evidence that the recently developed vitamin B (12) cream containing avocado oil has considerable potential as a well-tolerated, long-term topical therapy of psoriasis.”

The effect of various avocado oils on skin collagen metabolism. Werman MJ, Mokady S, Nimni ME, Neeman I. Connect Tissue Res. 1991;26(1-2):1-10. Key Finding: “The effects of various avocado oils on collagen metabolism in skin were studied in growing rats. Rats fed the unrefined avocado oil extracted with hexane from the intact fruit, its unsaponifiables or the avocado seed oil, showed significant increases in soluble collagen content in skin.”


Natural remedies for schleroderma. Gaby AR. Altern Med Rev. 2006 Sep;11(3):188-95. Key Finding: Avocado/soybean extract is a promising natural treatment for scleroderma, an autoimmune disease of the connective tissue characterized by fibrosis and thickening of various tissues.


Wound healing activity of Persea Americana (avocado) fruit: a preclinical study on rats. Nayak BS, Raju SS, Chalapathia Rao AV. J Wound Care. 2008 Mar;17(3):123-6. Key Finding: “Avocado oil is rich in nutrient waxes, proteins and minerals, as well as vitamins A, D and E. It is an excellent source of enrichment for dry, damaged or chapped skin. This study aimed to evaluate the wound-healing activity of fruit extract of Persea Americana in rats. Rate of wound contraction, epithelialization time, together with the hydroxyproline content and histological observations, supports the use of Persea Americana in the management of wound healing.”

source: Lindsay Johnson, Hippocrates Health Institute


The Mythological Dangers of High Cholesterol and High Fat


The Mythological Dangers of High Cholesterol and High Fat
by Gabriel Cousens, MD

The following is a excerpt from There is a Cure for Diabetes, Revised Edition.

Clarity is needed on the question of risk/benefit ratio of low cholesterol, especially because 56 percent of Americans have a fear of fat and cholesterol. On my diet for treatment and prevention of diabetes, which is plant-based, cholesterol is not a particular concern, as 159 is high enough to be safe. The main reason I am dissecting the “high- cholesterol danger myth” is that it has resulted in dangerous low-fat dietary practices. In specific to the Dr. Cousens’s Diabetes Recovery Program—A Holistic Approach and in a larger holistic context, the increase in healthy fats supports the macronutrient calorie shift away from carbohydrates. This is additionally important since the research of the last 30 years shows that a serum cholesterol below 159 is unsafe, whereas serum cholesterol as high as 260–270 not only is perfectly safe but actually decreases cardiovascular mortality and increases longevity in women. What exactly is that 56 percent worried about, and are their worries justified or is it just a fearful, unscientific response to mythological hype?

As I have made it clear, all forms of carbohydrates in excess, including grains, fruits, and all sugars and sugar substitutes (except stevia and birch-tree-based xylitol), often result in an increased insulin resistance, obesity, increased triglycerides and increased levels of pathogenic small LDL particles. Empowered by the scientifically disproven idea that the “best way to protect your heart is a low cholesterol diet,” we can look at the whole cholesterol issue from a science-based perspective. Some of the more recent research that significantly nullifies the earlier speculative research gives us a new perspective of not only why I feel that a 25–45 percent fat diet, depending on constitution, is a safe way of reversing the degenerative process of Type-2 diabetes, but also why I feel (based on my clinical experience and more recent epidemiological scientific studies) that normal cholesterols as well as healthy levels of omega-3s are essential for long- term healthy function. The first thing I would like to point out is that in a 1992 editorial published in the Archives of Internal Medicine, Dr. William Pastelli, the former director of the Farmington Heart study, made an amazing statement: “In Farmington, Massachusetts, the more saturated fat one ate, the more cholesterol one ate and calories one ate, the lower the person’s serum cholesterol was.” It is easier to appreciate Dr. William Pastelli’s observation when one understands that the body makes 75 percent of its own cholesterol. The key in helping us understand this process is that the body of research shows that the liver produces three-to-four times more cholesterol than one eats and is always adjusting for the amount of cholesterol taken in orally. A low-cholesterol diet will increase production, and endogenous production decreases with large cholesterol dietary input. There’s a homeostasis going on. In addition, when one has a healthy insulin level, one tends to have a healthy cholesterol level because a healthy cholesterol is mediated by a healthy insulin level. This is a remarkable and important statement that is very much validated by the book The Cholesterol Myths by Uffe Ravnskov, MD, PhD, which offers many scientific arguments invalidating the idea that saturated-fat and cholesterol intake cause heart disease. His data and the data in general are overwhelming on this point.

Health Dangers of Low Cholesterol

My biggest concern in this discussion is the significant and pathological dangers with not only statins, as previously explained, but with cholesterol levels under 159. As a psychiatrist, I have been quite aware, for more than 40 years, of the serious mental illness dangers associated with low cholesterol. Recent research has shown that there is a much higher association of depression, suicidability, and anxiety with cholesterols less than 159. Several cohort studies on nondepressed subjects have assessed the relationship between plasma cholesterol and depression. Optimal membrane fat ratios positively affect the quality of neuro- transmission and neurotransmitter production. Low cholesterol is also associated with decreased serotonin receptors in the neurons (brain cells). In another study in relationship to cholesterol, called “Low Serum Cholesterol Concentration and Risk of Suicide,” adjusting for age and sex, they found that those with the lowest serum cholesterol concentrations had more than six times the risk of committing suicide. Another study found that if the cholesterol levels were equal to or below the twenty-fifth percentile, the risk of a suicide attempt doubled. Obviously from a holistic and psychiatric perspective, this is highly significant.

The Importance of Omega-3s for Health

Adequate omega-3 levels contribute to a healthy brain in a variety of important ways. They are important for maintaining and improving memory, cognition, sleep, neuromuscular control, and slowing the mortality of neurodegenerative diseases. Omega-3s also support new manufacture of acetylcholine, which is an important neurotransmitter needed for memory. They stimulate release of gamma-aminobutyric acid (GABA; which protects against anxiety, depression, pain, and panic attacks). Omega-3s are major components of brain tissue. They also help with brain and eye development in babies. Long- chain omega-3 are essential for prevention and treatment of all depression, including bipolar disorder. Recent studies investigating the epidemic of military suicides in Iraq and Afghanistan found that those who committed suicide had the lowest omega-3 levels in the military population. In specific, low DHA was associated with a 60 percent increase in suicide, making a clear point that adequate brain DHA is necessary for healthy brain and mental health function.

Adequate omega-3s improve mood regulation and treat impulsivity, hostility, and aggression.They improve dysfunction of monoaminergic systems including 5-hydroxytryptamine and serotonin. They help prevent cortisol, epinephrine, and norepinephrine elevations in biological and emotional stress. They reduce the risk of Parkinson’s disease and help proper nerve signaling. Adequate omega-3s are antiatherosclerotic in that they prevent fatty deposits and fibrosis of the inner layer of the arteries from forming. Adequate omega-3s lower triglyceride concentrations and improve endothelial function.They are a major factor in promoting the growth of new blood vessels. They tend to prevent thrombosis (a blood clot within a blood vessel), and they decrease cardiovascular risk factors. People with atrial fibrillation with high omega-3 levels have 85 percent lower risk of dying from all causes. Adequate omega-3 lowers blood pressure.

Omega-3s also have some anticancer benefits: They protect skin cells from cancer-causing effects of the sun and help decrease prostate cancer risks. In premenopausal women, a high omega-3 to omega- 6 ratio resulted in a decreased rate of breast cancer by 50 percent. Omega-3s constitute 50 percent of our cell membranes and give our cells optimal stiffness, flexibility, integrity, and function. They improve liver health and protect the liver from toxins. They help build a strong immune system. They contribute to healthy lungs and also have an anti-inflammatory in counteracting inflammation (heat, pain, swelling, etc.). They protect organs and tissues from inflammation in general.

From an Ayurvedic perspective, deficient omega-3s, as well as inadequate cholesterol, create an imbalanced “vata” mental state with poorer cognition, memory, and functioning. This results in lower life-force, lower vitality, and generally a lower reserve of vital life-force and sexual energy. Along with this there may be depression, violence, anxiety, and even suicide. The Ayurvedic term for this is vital reserve is ojas, which means deep primordial vigor and reserve. Low ojas results in a generally weakened physical, emotional, mental, and spiritual condition. In this larger context, the overall effect of a low-fat diet has serious, global, negative ramifications for quality of life. To balance the vata Ayurvedic dosha, and specifically for calming a vata dosha imbalance (which, in essence, is the clinical description I have given of an omega- 3, long- and short-chain deficiency, as well as a cholesterol deficiency), I highly recommend adequate raw plant-source-only fat consumption in one’s diet to prevent Ayurvedically described “vata” physical and mental imbalances.

In summary, low-cholesterol and low-omega-3s have been shown through overwhelming scientific evidence to be a danger to the general health and longevity of the individual. The “extremely low cholesterol is good for your heart” and extreme low-fat mythology campaign is based on bad science and fear, which has, by 2011, been disproved. Saturated fat and omega-3 intake from plant-based fat is actually cardioprotective, brain- and mental-health protective, general-health protective, and life-force protective. This higher fat intake creates a macronutrient balance with the 25–45 percent carbohydrate direction, with its higher vegetable and nut and seed fat. A higher fat diet allows the potential for a lower protein in the diet, which is important when one understands about the glycemic impact of excess protein intake. Research more strongly suggests that high insulin is more linked to cardiovascular disease than the “cholesterol link.” There is a distinction between association and causal effect. Causal means a direct link and thus a stronger effect. There’s a causal link between high insulin and high leptin and heart disease and diabetes. There is neither an association nor a causal relationship between cholesterol and heart disease. The key to cardiovascular disease and diabetes is an imbalanced, dysfunctional insulin and leptin signaling secondary to excess carbohydrates, which of course is perhaps the key to all chronic diseases but particularly coronary disease.