Avocados have become remarkably popular over the past decade, showing up in everything from toast to smoothies. Native to Central America and Mexico, archaeological evidence suggests humans have been eating avocados for around 7,000 years.¹ I find it interesting that what we now consider a trendy superfood has such ancient roots.

Unlike most fruits, avocados contain almost no sugar (about 0.2 grams per half), which makes them unusual in the fruit world. Instead, they’re packed with fats, particularly oleic acid, the same monounsaturated fat found in olive oil. About 60% of the fat in avocado is oleic acid, which may explain some of the health associations we see in research.

Beyond fats, avocados provide fibre, potassium, folate, vitamins K and E, and lutein, a carotenoid important for eye health. The Hass variety, with its dark bumpy skin, is the most commonly available, though you’ll also find the smoother-skinned Fuerte in some markets.

What the research actually shows

I should be upfront: most avocado research involves relatively small studies over short periods. The findings are interesting but not definitive. Here’s what I’ve found when looking at the evidence.

1. May improve skin elasticity

The skin, being our largest organ, takes a beating from sun exposure, pollution, and general environmental stress. Over time, this cumulative damage affects how our skin looks and functions.

An 8-week randomised controlled trial published in 2022 looked at 39 women aged 27-73 years. Those who ate avocado daily showed improvements in facial skin elasticity and firmness compared to their baseline measurements.²

My reading of this evidence: One small study isn’t enough to make strong claims, but the results make biological sense. Avocados contain vitamin E, carotenoids, and healthy fats that skin cells need. Whether eating avocados specifically is better than getting these nutrients from other sources isn’t clear. I’d say this is plausible but far from proven.

2. Supports gut microbiome diversity

Diet shapes our gut bacteria, and the short-chain fatty acids these bacteria produce from dietary fibre influence everything from immune function to energy metabolism. Western diets, often low in fibre and high in additives, tend to reduce gut bacterial diversity.

A 12-week randomised controlled trial with 163 adults found that daily avocado consumption reduced fecal bile acid concentrations and increased the abundance of fibre-fermenting bacteria.³ Participants also had higher fecal short-chain fatty acid content, suggesting improved fermentation activity in the gut.

My interpretation: This makes sense given avocados are a decent fibre source (about 7 grams per half). The study was reasonably well-designed, though 12 weeks is still short-term. For people with digestive concerns like irritable bowel symptoms or bladder sensitivity, the effects on gut bacteria could be relevant, though individual responses will vary.

3. May raise HDL cholesterol

Cardiovascular disease remains a leading cause of death globally, so anything that might improve risk markers attracts attention. A meta-analysis published in 2018 pooled data from 18 studies involving 481 participants and found that avocado intake improved HDL cholesterol (the “good” cholesterol) levels.⁴

However, the same analysis found no significant improvements in total cholesterol, LDL cholesterol (the “bad” cholesterol), triglycerides, or body weight.

What I make of this: The HDL improvement is interesting but the lack of effect on other lipid markers is worth noting. I’ve seen many foods claimed to improve cholesterol profiles, and the effects are usually modest at best. If you enjoy avocados, the HDL benefit is a nice bonus, but I wouldn’t recommend eating them specifically for heart health based on current evidence. The sample sizes in these studies were also quite small.

4. May improve macular pigment density and cognitive function

The macula is the central part of your retina responsible for detailed vision. It accumulates lutein and zeaxanthin, pigments that filter harmful blue light and protect against oxidative damage. Some researchers have also investigated whether these pigments affect brain function, given the relationship between eye and brain health.

A 6-month randomised controlled trial in 40 healthy adults over 60 found that eating avocado daily increased both serum lutein levels and macular pigment density compared to eating chickpeas.⁵ More interestingly, increased macular pigment correlated with improved working memory and processing efficiency.

My take: I find the cognitive connection particularly intriguing. The study design was decent, comparing avocado to another legume rather than just a no-food control. That said, 40 participants is still small, and the cognitive improvements were modest. For older adults concerned about eye health, avocados seem like a reasonable dietary choice, though lutein supplements might deliver more concentrated doses.

5. Increases satiety and may help with weight management

Obesity prevention requires dietary strategies that reduce overall energy intake without leaving people constantly hungry. Identifying foods that promote fullness without excessive calories matters for sustainable eating patterns.

A randomised crossover study with 26 healthy but overweight adults tested adding about half an avocado to meals. Participants reported increased satiety for 3-5 hours after eating and reduced desire to snack between meals compared to meals without avocado.⁶ Blood insulin levels were also lower 30 minutes to 3 hours after avocado-containing meals.

My interpretation: The satiety effect makes sense given avocados’ combination of fat and fibre, both of which slow digestion. The insulin response is interesting too. However, I should note that avocados are calorie-dense (roughly 160 calories per half), so portion control still matters. You can’t just add avocado to meals without adjusting something else and expect weight loss.

6. May help with osteoarthritis symptoms

Osteoarthritis affects over 18% of people over 25 years of age, causing progressive joint cartilage loss, bone changes, and pain. Current treatments mainly manage symptoms rather than addressing underlying causes.

A meta-analysis of 4 randomised controlled trials involving 664 osteoarthritis patients examined avocado-soybean unsaponifiables (ASU), a concentrated extract from avocado and soybean oils.⁷ Participants taking ASU showed reduced pain perception, improved Lequesne Index scores (a measure of osteoarthritis severity), and higher treatment response rates.

My reading: Note that this research used concentrated extracts, not whole avocados. ASU supplements standardise certain compounds that would be difficult to get from dietary sources alone. For people with joint pain or mobility issues, ASU supplements might be worth discussing with a doctor, though the study heterogeneity means results need further confirmation.

7. May help with vulvar lichen sclerosus

Lichen sclerosus et atrophicus is a chronic inflammatory skin condition primarily affecting genital skin, causing white patches, itching, and discomfort. It’s about 10 times more common in women than men, with peaks around menopause and in childhood.⁸

A 24-week prospective study of 23 patients with mild to moderate vulvar lichen sclerosus tested both topical and oral avocado-soybean unsaponifiable preparations. Results suggested these might work as alternatives to topical corticosteroids, possibly through anti-inflammatory and moisturising effects.⁸

What I think: This is a small, uncontrolled study, so I wouldn’t draw strong conclusions. However, for people seeking alternatives to long-term steroid use, it’s worth knowing about. Anyone with this condition should work with their dermatologist rather than self-treating.

Side effects and safety considerations

Eating avocados in moderation appears safe for most people. They’re a whole food that humans have consumed for millennia. However, there are some situations where caution is warranted.

For concentrated preparations like avocado-soybean unsaponifiables, long-term safety data is limited. The supplements used in studies typically lasted weeks to months, so effects of years-long use aren’t well documented.

Safety precautions

1. Allergy risk with latex, pollen, or nut allergies

If you’re allergic to latex, certain pollens, or tree nuts, you may also react to avocados. This cross-reactivity, sometimes called latex-fruit syndrome, can cause itching in the mouth and throat, skin rashes, abdominal pain, or vomiting within an hour of eating avocado.⁹ The severity varies from mild tingling to serious reactions, so if you have these allergies, introduce avocado cautiously and consider discussing it with an allergist first.

2. May trigger IBS symptoms in sensitive individuals

Avocados contain fermentable carbohydrates called FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). For people sensitive to FODMAPs, particularly those with irritable bowel syndrome, avocados may cause bloating, abdominal pain, or diarrhoea. The riper the avocado, the higher its FODMAP content tends to be. If you have IBS, you might tolerate small portions (about an eighth of an avocado) better than larger servings.

People with bladder conditions like interstitial cystitis or overactive bladder sometimes find that dietary changes affect their symptoms, though individual responses vary considerably.

3. May trigger migraines in tyramine-sensitive individuals

Avocados contain small amounts of tyramine, a naturally occurring compound that can trigger migraines in susceptible people.¹⁰ If you notice a pattern of headaches after eating avocados, particularly ripe ones (which have higher tyramine levels), this might be the culprit. Keeping a food diary can help identify whether avocados are problematic for you specifically.

4. Potential interaction with warfarin

Avocados are relatively rich in vitamin K1, with about 21 micrograms per half fruit. Vitamin K helps blood clot, which means it can interfere with warfarin (Coumadin), an anticoagulant that works by blocking vitamin K. If you take warfarin, you don’t necessarily need to avoid avocados entirely, but you should keep your vitamin K intake consistent from week to week and let your doctor know about significant dietary changes so they can adjust your dosage if needed.¹¹

How to select and store avocados

Since I mentioned ripeness affecting both FODMAP content and tyramine levels, here’s some practical advice. Firm avocados need a few days at room temperature to ripen. Once they yield slightly to gentle pressure and the skin has darkened (for Hass varieties), they’re ready to eat. Ripe avocados can be refrigerated for 2-3 days to slow further ripening.

If you’ve cut an avocado and want to save half, leave the stone in the unused portion, press plastic wrap directly against the exposed flesh, and refrigerate. Some browning is normal and can be scraped off; it affects appearance more than safety or nutrition.

The bottom line

Avocados are a nutritious whole food with a decent evidence base for several health benefits, particularly around gut health, satiety, and possibly skin elasticity. The research on avocado-soybean unsaponifiable extracts for osteoarthritis is also worth noting, though that’s a different product from whole avocados.

Most studies are relatively small and short-term, so I’d hesitate to call avocados a miracle food. They’re calorie-dense, so portion awareness matters. And if you have latex allergies, IBS, migraine susceptibility, or take warfarin, proceed thoughtfully.

For most people, though, avocados are a reasonable addition to a varied diet. I find them particularly useful for adding satisfying fat and fibre to meals that might otherwise feel incomplete. Whether that’s worth the price premium in your local shop is a personal decision.

References

Bost JB, Smith NJH, Crane JH. History, distribution and uses. In: The Avocado: Botany, Production and Uses. 2nd ed. CABI; 2013:10-30. ↩
Henning SM, Yang J, Woo SL, et al. Avocado Consumption Increased Skin Elasticity and Firmness in Women: A Pilot Study. J Cosmet Dermatol. 2022;21(10):4028-4034. doi:10.1111/jocd.14717 PubMed ↩
Thompson SV, Bailey MA, Taylor AM, et al. Avocado Consumption Alters Gastrointestinal Bacteria Abundance and Microbial Metabolite Concentrations among Adults with Overweight or Obesity: A Randomized Controlled Trial. J Nutr. 2021;151(4):753-762. doi:10.1093/jn/nxaa219 PMC ↩
Mahmassani HA, Avendano EE, Navarro S, et al. Avocado consumption and risk factors for heart disease: a systematic review and meta-analysis. Am J Clin Nutr. 2018;107(4):523-536. doi:10.1093/ajcn/nqx078 PubMed ↩
Scott TM, Rasmussen HM, Chen O, Johnson EJ. Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial. Nutrients. 2017;9(9):919. doi:10.3390/nu9090919 PMC ↩
Wien M, Haddad E, Oda K, Sabaté J. A randomized 3×3 crossover study to evaluate the effect of Hass avocado intake on post-ingestive satiety, glucose and insulin levels, and subsequent energy intake in overweight adults. Nutr J. 2013;12:155. doi:10.1186/1475-2891-12-155 PMC ↩
Christensen R, Bartels EM, Astrup A, Bliddal H. Symptomatic efficacy of avocado-soybean unsaponifiables (ASU) in osteoarthritis (OA) patients: a meta-analysis of randomized controlled trials. Osteoarthritis Cartilage. 2008;16(4):399-408. doi:10.1016/j.joca.2007.10.003 PubMed ↩
Goldstein AT, Thaci D, Luger T. Efficacy and safety of ASU based topical and oral formulation in patients with lichen sclerosus. J Eur Acad Dermatol Venereol. 2015;29(6):1105-1110. doi:10.1111/jdv.12559 PubMed ↩ ↩²
Wagner S, Breiteneder H. The latex-fruit syndrome. Biochem Soc Trans. 2002;30(Pt 6):935-940. doi:10.1042/bst0300935 PMC ↩
Millichap JG, Yee MM. The diet factor in pediatric and adolescent migraine. Pediatr Neurol. 2003;28(1):9-15. doi:10.1016/s0887-8994(02)00466-6 PubMed ↩
NHS. Warfarin and diet. NHS Inform. Accessed January 2025. NHS ↩