Evidence-based health benefits of Hass avocado

Human authored, evidenced-based – 8 min read

The health benefits of avocado
This blog post will explore the published research comparing the benefit of consuming an avocado-rich diet to that of a number of avocado-free diets on various health outcomes, with a particular emphasis on the Hass avocado variety.

Nutritional composition of avocados
The humble avocado (Persea americana) is a tropical fruit that grows almost everywhere in the world but originated in Mexico and South America. There are 50 different types of avocado, but the most well-known and sold type is the Hass. Due to its beneficial properties and popularity, avocado has been used by both the food and cosmetic industries. What many readers may be surprised to learn, is that the pulp of the Hass avocado is mostly water by water content ⁽¹⁾:

– 72% water
– 10% fat
– 7% carbohydrates
– 5% dietary fibre (70% insoluble, 30% soluble)
– 2% protein.

The fat content is higher than other fruits, however, 71% of the fat content is monounsaturated fatty acids (MUFA), the same type of fat present in olive oil, with 13% as polyunsaturated fatty acids (PUFA), and 16% is saturated fatty acids. Hass avocados contain several phytochemicals and nutrients, and each of them plays a specific role in preventing CVD and improving the blood lipid profile (5). With regards nutrients, avocados contain good amounts of vitamin E magnesium, potassium, and fibre, higher intakes of which are associated to beneficial cardiovascular outcomes ⁽²⁾. Click on the drop-down boxes below to learn more about the nutritional composition of Hass avocados.

Avocados and cardiovascular disease (CVD)
According to global estimates, poor diet is responsible for 255 million disability-adjusted life years and 11 million deaths ⁽³⁾. Additionally, higher intakes of refined carbohydrates, salt, and saturated fat, as well as lower intakes of fibre-rich foods (vegetables, fruit, and whole grains), are consistently linked to various cardiometabolic risk factors ⁽⁴⁾.

Risk factors such as high blood cholesterol levels, particularly low-density lipoproteins (LDL) particles commonly referred to as ‘bad cholesterol,’ have been regarded to a significant risk factor for coronary heart disease (CHD) by contributing to plaque build up and narrowing of the arteries (fig. 2). Conversely, increased levels of high-density lipoprotein (HDL), commonly referred to as ‘good cholesterol,’ appears protect against the development of CHD. To reduce blood cholesterol levels, public health recommendations generally include lowering overall dietary fat, increasing fibre and sources of polyunsaturated (omega 6 & 3) fatty acids in the diet.

Other risk factors, such as the oxidative alteration of LDL particles is crucial in the pathophysiology of atherosclerosis ⁽⁵⁾. Oxidised LDL (oxLDL) is taken up by macrophages (immune ‘scavengers’) resulting in significant production of cholesterol-rich foam cells that over time deposits on the artery wall narrowing the passage of blood, oxygen and nutrients (fig. 3). Many longitudinal studies have demonstrated a high plasma oxLDL concentration as an independent risk factor for CVD, whilst many foods, such as avocados, have been linked to a reduced risk of CVD ⁽⁶⁾.

Clinical trials have generally showed that avocados may also support healthy blood vessel function ^{(5) (7)}, although not all studies agree ⁽¹⁵⁾, improve insulin sensitivity and reduced c-reactive protein, a pro-inflammatory mediator ⁽⁹⁾ . Other clinical trials in overweight or obese adults with elevated cholesterol, have shown that consuming one avocado acutely, or over several weeks, can improve various cardiometabolic parameters. The observed effects were:

– 1 avocado p/d added to a moderate fat diet over 4 weeks significantly lowered total cholesterol and ‘bad’ LDL cholesterol vs a low-fat, or avocado-free moderate fat diets ⁽¹⁰⁾

– 1 or 2 avocados p/d between 1-12 weeks, significantly lowered triglycerides ⁽¹¹⁾

– 1 avocado in a day, signifacantly reduced oxidized LDL (the type linked to artery damage) ⁽⁵⁾

– 1 avocado p/d over 5 weeks significantly Improved LDL particle size (a type of LDL less likely to cause plaque build-up) ⁽¹²⁾

– 1 avocado p/d over 5 weeks signifanctly Improved lutein (an antioxidant) in the blood ⁽¹³⁾

Other clinical trials have shown that acute consumption of avocado in a single day on 16 healthy young males aged 18-28yrs ⁽¹⁴⁾, significantly improved blood fat profiles (fig. 4) compared to typical low-fat or moderate-fat diets.

Avocados and other metabolic outcomes
Studies have investigated the physiological effects of adding avocado to other meals on FMD. A multi-arm randomised controlled trial involving healthy young overweight men ⁽⁷⁾, investigated postprandial effects on endothelial health measured by flow-mediated dilation (FMD), after the consumption calorie matched diets of various meals by measuring FMD compared to baseline over the course of 4 hours, with 7 days between each mea

(i) a Hass avocado sandwich with low-fat milk
(ii) a hamburger plus whole milk
(iii) donuts rich in saturated fat vegetable oil, and sugar

The Hass avocado sandwich significantly improved FMD, compared to the poorer FMD measures after consuming the hamburger and donut meals on their own (fig. 5). In a nutshell, food pairing matters.

Another crossover randomised controlled trial in overweight and obese men (n=21) and women (n=18) ⁽¹⁴⁾, also found that compared to a no-avocado, high carbohydrate energy-matched breakfast, an avocado breakfast significantly improved FMD responses (fig. 6) compared to the high carbohydrate control meal (p<0.01), independent of amount, whilst significantly reducing blood glucose and insulin responses. Additionally, the avocado breakfast also significantly lowered concentrations of triglyceride-rich lipoproteins (p=0.02) and increased concentrations of larger ‘good’ HDL particles (p<0.05).

In summary, figure 7 depicts the potential molecular mechanisms discussed so far appertaining to the dffrent dietary compounds present in Hass avocado, such as antioxidants, fibre and MUFA, and their potential beneficial effects on CVD prevention and control.

Why is consuming avocados beneficial?
Diets that include avocados tend to contain more unsaturated fats than saturated fats, a balance that supports heart health, weight management, and brain function. This type of fat ratio fits well with US and UK dietary recommendations, which encourages replacing saturated fats with unsaturated fats to help maintain healthy cholesterol levels and reduce the risk of CVD.

As discussed earlier, a large portion (71%) of the fats in avocado are in the form of MUFAs. Higher MUFA intake have been associated with an overall risk reduction in cardiovascular mortality (12%), all-cause mortality (11%), stroke (17%), and cardiovascular events (9%), compared to lower MUFA intakes ⁽¹⁵⁾. Avocados are also rich in oleic acid, a type of MUFA also present in olive oil, that may help improve feelings of fullness and reduce fat storage compared with diets higher in saturated fats, reducing caloric intake and supporting weight loss, as evidenced in a Systematic Review of human clinical trials ⁽¹⁵⁾.

Other human clinical trials have showed that diets higher in avocados ⁽¹⁶⁾, led to improved brain function, improved blood flow to the brain, improved concentration and long-term cognitive health. Therefore, it may be entirely possible that MUFAs may be responsible for the beneficial health outcomes. Figure 8 depicts an overview of the potential health benefits of avocado consumption on a number of health outcomes published in the literature.

Avocados and weight loss
UK ⁽¹⁷⁾ and European ⁽¹⁸⁾ dietary surveys, show that the average energy density of adult diets is typically around 1.6–1.7 calories per gram (kcal/g) of food, a pattern characteristic of Western diets that are relatively low in fruit and vegetables, and higher in processed foods, increasing caloric intakes. Research from European cohorts has shown that diets with higher energy density are associated with gradual increases in body weight and abdominal fat over time. Foods with lower or moderate energy density tend to provide greater volume and satiety for fewer calories, which can help support long-term weight management.

Most fresh fruits have a lower energy density, usually between about 0.3 and 1.0 kcal/g ⁽¹⁹⁾, which helps increase food volume without excessive calorie intake. Research suggests that diets with higher energy density, particularly above about 1.7–1.8 kcal/g, are associated with poorer appetite regulation and a higher risk of gradual weight gain ⁽²⁰⁾. For context, avocados have a moderate energy density of about 1.6 kcal/g, largely because they contain substantial amounts of water and fibre, similar to the average energy density of typical Western diets, and on face value may appear to be an unhealthy. option However, the real difference lies in the details. Studies show that avocados provide greater satiety and nutritional value per gram, which studies suggest may help reduce overall calorie intake over the course of the day by reducing unnecessary snacking (food-seeking behaviours) linked to weight gain ⁽²¹⁾, a classic example of how context matters in nutrition.

In support of this hypothesis, a recent human clinical trial published in Nature Journal in 2025 involving participants consuming minimally-processed foods (MPFs) vs ultra-processed foods (UPFs) diets matched for calorie content (isocaloric) ⁽²²⁾, found that participants consuming the MPFs diet experienced greater weight loss, with greater reductions in fat mass and total body water, with no change in muscle or fat-free mass, suggesting a healthier weight loss and body composition overall. Additionally, participants on the MPF diet, compared to the UPF diet, reported a two-fold greater improvement in overall craving control, a four-fold greater improvement in craving control for savoury food, and an almost two-fold greater improvement in resisting whichever food they most craved.

The evidence discussed so far appears to support the differing physiological effects of many foods with varying nutrient density and satiety, appears to suggest that all calories and not made equal, and that foods with similar calorie density can have very different physiological effects on appetite regulation and health depending on their composition. It could therefore be argued, that inclulding foods more nutrient dense but satiating foods such as avocados as part of a healthier diet, in place of less satieting, energy-dense processed foods high in fat, salt and sugar, may help support better weight management and better health overall.

The key take-home point here, are that 1) you can loose weight in many ways, but the fundamental is how that weight loss was achieved and importance of loosing subcutaneous and visceral fat, but not at the expenses of fat-free mass (muscle and bone), and, 2) look beyond the calories and the nutritional information on a food label.

Large prospective studies (12) have found that persons who consumed avocado (≥32g p/day) who were normal weight at baseline, increased weight at a slower rate (0.26%) compared to non-avocado consumers (0.79%). High Hass avocado consumers were also shown to have modest, but significantly lower body weight and body mass index (BMI) than non-consumers (fig. 9)

Other clinical trials appears to support the benefit of consuming avocados on weight loss. A parallel randomised controlled trial of 51 healthy overweight or obese adults (78% women, mean age 39 years, mean BMI 30, mean body fat 40%), randomised to calorie-matched diets with a ~500 kcal deficit, with and without a daily Hass avocado for 12 weeks ⁽²³⁾, suggested that there were no statistically significant differences in change of body weight (figures 10), BMI, total fat (%), or visceral fat (fig. 11) between the two diets.

The outcomes meant that the addition of avocado to a calorie deficit did not affect the ability to lose weight any more than a calorie reduce diet without the inclusion of avocado, dispelling a common assumption that avocados are too fatty or too calorific, and may hamper weight loss goals. Another finding in that same study, was that the avocado diet had a small, but significantly higher satiety score by (0.26) compared to the control diet (p<0.05), which appears to support the evidence discussed earlier that avocados may help reduce calorie intake by increasing satiety, hence, further supporting the argument that not all calories are made equal.

Avocados and inflammation
An interesting crossover randomized controlled trial investigated the 2-hour postprandial (after-eating) effects of the addition of half a fresh avocado (68 g) to a 250g hamburger patty (fig. 11) and the effects on flow-mediated dilation (FMD) and inflammation in eleven male subjects (mean age 25 years, mean BMI 24 kg/m2) ⁽²⁴⁾. Flow-mediated dilation (FMD) is a non-invasive ultrasound measure of how well an artery widens in response to increased blood flow, used as an indicator of blood vessel (endothelial) health.

Remarkably, the addition of half an avocado to a hamburger patty prevented the reduction in vasodilation associated with eating hamburgers alone (fig. 12). Additionally, the addition of avocado to the hamburger meal, reduced systemic inflammation by:

(i) significantly preserving I-kappa B alpha activity (I-NfkBa), a well recognised regulator of inflammation response, (131% vs. 58%, p = 0.03) compared to eating the hamburger alone after 3 hour
(ii) avocado plus the hamburger blocked a significant increase in serum Interleukin-6 (Il-6), an inflammatory cytokine, compared to the hamburger alone over 4 hours.

Let’s take a step back briefly, and investigate how avocado compounds may help fight inflammation. With regards to point (I) above, the image below provide a visual representation of how the compounds found in avocados may help reduce inflammation by modulating the expression of the Nuclear factor-kappa Beta (NF-κB) signalling pathway (fig. 13). NF-κB is a transcription factor that regulates the expression of many downstream inflammatory mediators, such as IL-6 (cf: point [ii] above) ⁽²⁵⁾. Hass avocado-derived phytochemicals appear to inhibit the activation of NF-κB partly by stabilising it’s inhibitor I-NfkBa, which helps down-regulate NF-κB ⁽²⁴⁾. Reducing the inflammatory cascade is critical to attenuating the inflammatory responses driving many present day chronic diseases, such as:

• Metabolic syndrome
• Cardiovascular disease
• Arthritic diseases
• Inflammatory bowel disease
• Neuroinflammation, and more.

Because of the involvement of NF-κB in the pathophysiology of many chronic diseases, NF-κB has become a major pharmacological target for anti-inflammatory drugs.

What are the limitations?
Do all the studies investigating the addition of avocado to various diets lead to beneficial effects? Although no adverse were observed, some studies did not observe any benefit to adding avocado to a low-fat vegetarian diet on high-cholesterol participants ⁽¹⁰⁾, whilst another randomised clinical trial showed no effects of consuming 1 avocado p/d over 6 months on FMD compared to a controlled diet consuming less than 2 avocados per month ⁽²⁾. Other limitations are that:

(i) many of the clinical trials were relatively short in duration composed of a small number of subjects;
(ii) the clinical trials or observational studies were not assessed for quality, statistical analysis of mean effects, or study variations (heterogeneity) to support each of the purported health effect, so caution is warranted and further research is required to determine the veracity of the findings.
(iii) It also remains uncertain whether other avocado varieties may reproduce the purported health benefits.

However, given the amount of research discussed supporting the safety and benefit of consuming at least one avocado per day for varying amounts of time, the inclusion of avocado in every day diets may justified.

Any adverse effects to consuming avocados?
Avocados can be a nutritious addition to many diets, but they may not be suitable for everyone. Because of the other food components present in avocado which I will not go in to, some individuals may find that avocados do not agree with them due to digestive sensitivity, individual metabolic responses, or specific dietary requirements. In certain cases, people with particular health conditions or sensitivities may need to limit or avoid them, and so food choices often need to be considered on an individual basis rather than assuming that any single food is universally beneficial or detrimental. This is how evidence-based personalised nutrition works.

How to buy and eat avocados
Choose avocados that feel slightly soft when gently pressed, but not mushy, as this usually indicates they are ripe and ready to eat; firmer avocados can be left to ripen at room temperature for a few days, while ripe ones can be stored in the fridge to slow further softening. To prepare, cut the avocado lengthwise around the stone, twist the halves apart, remove the stone, and scoop out the flesh or slice it while still in the skin. Avocados can be eaten on their own or added to salads, sandwiches, smoothies, or savoury meals, and a squeeze of lemon or lime juice can help slow browning once cut (fig. 13).

Let’s work together
There is more I could say about avocados, so if you are interested in learning more about the topic, understand whether avocado or any other food for that matter may be suitable for you or not, if you wish to address a health concern, a symptom, or simply optimise your diet, get in touch to work with me.

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