Holy guacamole! Eating avocado may reduce cardiovascular risk

+Practice
In print
HEARTBEAT + FREE READ

Holy guacamole! Eating avocado may reduce cardiovascular risk

Chris Ellis

Chris Ellis

4 minutes to Read
Avocado
There seems to be an opportunity for New Zealand to grow and export more “heart-healthy” avocados [Image: Eddie Pipocas on Unsplash]

Consultant cardiologist Chris Ellis reviews the evidence for the cardiovascular benefits of eating avocado

Key points
  • A large, observational, epidemiological study has reported that two or more servings of avocado a week reduces cardiovascular disease events.
  • All adult patients should have a CVS risk assessment scheduled at least every five years.
  • Over time, CVS risk assessments are changing from the traditional, epidemiological, equation-based to the more accurate arterial imaging-based assessments.

This article has been endorsed by the RNZCGP and has been approved for up to 0.25 CME credits for continuing professional development purposes (1 credit per learning hour). To claim your credits, log in to your RNZCGP dashboard to record this activity in the CME component of your CPD programme.

Nurses may also find that reading this article and reflecting on their learning can count as a professional development activity with the Nursing Council of New Zealand (up to 0.25 PD hours).

A 46-year-old maths teacher comes for review and to consider her risk of “heart disease”. She is interested as her maternal grandfather died from a heart attack at age 79. In addition, she tutors a group of 14-year-old students at the local college, and there had been a recent discussion among the group about the potential benefits of eating avocado as part of a packed lunch.

Your patient is a non-smoker, who only drinks about five units of wine a week. She walks with her girlfriends three mornings a week before school, and with her husband in the weekends. She eats a balanced diet, rarely eats takeaways and is of healthy weight.

She has no significant past medical history and does not take any regular medications. Her parents and two older brothers are well. Her other three grandparents lived into their 80s and 90s, and did not experience a cardiovascular (CVS) event. She is happily married, with three children aged 10 to 18.

Her examination is normal, her blood pressure is 125/75mmHg, and she has normal biochemistry and haematological blood test results, including a total cholesterol level of 4.0mmol/L with a low-density lipoprotein cholesterol level of 2.0mmol/L. You take the opportunity to obtain a baseline electrocardiogram.

  1. What does the ECG show?
  2. What advice might be suitable for your patient regarding her CVS risk?
  3. What tests might potentially be of help?
  4. Is eating avocado “good for the heart”?
  5. How good is the evidence?
  6. How does New Zealand stack up globally as an exporter of avocados?
  7. How might you summarise the current knowledge on diet for her tutor group?
ECG supplied
Discussion

To have a definite ‘booking’ to consider cardiovascular risk throughout a patient’s life allows the question to be intermittently addressed

1. The ECG shows sinus rhythm, a normal axis and a rate of 61 beats per minute. As expected, it is normal.

2. All clinicians will realise she is at low personal CVS risk. Her lifestyle should be encouraged, and a further review of her CVS risk after five years would be reasonable. To have a definite “booking” to consider CVS risk throughout a patient’s life allows the question to be intermittently addressed. It should be remembered that low risk does not mean no risk.

3. The Progression of Early Subclinical Atherosclerosis (PESA) study from 2015 reported on 4182 participants in a fascinating analysis of the extent of subclinical atherosclerosis within an asymptomatic Mediterranean population (63 per cent male). The average age of these Madrid bank workers was 46 years. A positive CT calcium score test was seen in 5 per cent of women and 25 per cent of men. Carotid atherosclerotic plaque was seen by ultrasound in 24 per cent of women and 34 per cent of men.1

You briefly discuss these more accurate “imaging” techniques to assess CVS risk, but decide to leave these tests for another five years, until your patient’s next CVS risk assessment. In her case, it just seems too soon to do this now, despite the PESA study!

4. You have become less enthusiastic about the regular continuing medical education Zoom meetings, which have resulted from the COVID-19 era, and you are now looking forward to face-to-face meetings (hopefully) in the near future. You and your friends have been distributing interesting papers via email, which you are often reading instead. With perfect timing, a colleague recently sent you a remarkable paper from the Journal of the American Heart Association.2

The paper reported on more than 110,000 men and women (combined from two separate studies) who were followed for more than 30 years. Results suggested that eating two or more servings of avocado a week reduces CVS events. After adjustment for lifestyle and other dietary factors, those with a higher avocado intake had a 16 per cent lower risk of CVS disease (95 per cent confidence interval 0.75–0.95) and a 21 per cent lower risk of coronary heart disease (95 per cent CI 0.68–0.91).2

5. You and your friend are both clear that this was an observational epidemiological study, unable to prove cause and effect. Nonetheless, the paper is of interest and consistent with many large trials now supporting a healthy dietary pattern as a key method of reducing CVS disease. A variety of contemporary studies support a diet that includes fresh salad, fruits, vegetables, grains, legumes, fish and, in reasonable amounts, meat, eggs and dairy. There might also be a role for intermittent fasting for 12 to 16 hours per day.3

6. The New Zealand Horticulture Export Authority website reports that as well as the local market, New Zealand currently produces 2 per cent of the global supply of avocados. We are the ninth largest international avocado exporter, being focused on the Asian market in particular.

There certainly seems to be room to expand this export of good, healthy food from our shores.

7. A succinct dietary message might be to limit processed foods, eat all fresh foods in moderation and, above all, to not put on excess weight. Oh, and enjoy your avocados!

Details have been changed to protect patient confidentiality

Chris Ellis is a consultant cardiologist at The Heart Group and Mercy Hospital, Auckland

Thinking about learning? 

You can use the Capture button below to record your time spent reading and your answers to the following learning reflection questions:

  • Why did you choose this activity (how does it relate to your professional development plan learning goals)?
  • What did you learn?
  • How will you implement the new learning into your daily practice?
  • Does this learning lead to any further activities that you could undertake (audit activities, peer discussions, etc)?
FREE and EASY

We're publishing this article as a FREE READ so it is FREE to read and EASY to share more widely. Please support us and the hard work of our journalists by clicking here and subscribing to our publication and website

PreviousNext
References

1. Fernández-Friera L, Peñalvo JL, Fernández-Ortiz A, et al. Prevalence, vascular distribution, and multiterritorial extent of subclinical atherosclerosis in a middle-aged cohort: The PESA (Progression of Early Subclinical Atherosclerosis) study. Circulation 2015;131(24):2104–13.

2. Pacheco LS, Li Y, Rimm EB, et al. Avocado consumption and risk of cardiovascular disease in US adults. J Am Heart Assoc 2022;11(7):e024014.

3. O’Keefe JH, Torres-Acosta N, O’Keefe EL, et al. A Pesco-Mediterranean diet with intermittent fasting: JACC review topic of the week. J Am Coll Cardiol 2020;76(12):1484–93.