The Blood Type Diet. Fab or fad?

The Blood Type Diet. Photograph by Samuel Zeller.

Last week the wonderful freelance beauty and lifestyle journalist Becci Vallis, picked my brain on the Blood Type Diet for her article in Byrdie. It was a really interesting conversation and reminded me of how important it is to double check the scientific research behind the latest diet trends. Here's what I had to say:

What is the Blood Type Diet?

The Blood Type Diet has recently gained popularity, but it is definitely not a new trend. In fact, Naturopath Dr Peter d’Adamo published the diet back in 1996 in his book ‘Eat Right 4 Your Type’. The diet is based on the idea that during our evolution, exposure to eating different foods led to blood adaptations that resulted in 3 blood types – A, B and O. Apparently, each of these different blood groups adapted to different diets. So, in theory, whichever blood group you are, you carry the genetic message of the diets and behaviours of your ancestors; it’s a blueprint of how we should live and eat for optimal wellbeing.

Who is it recommended for?

Steak wrap. Photograph by Christine Siracusa.

The diet claims to be suitable for everyone. You just have to know what your blood type is. Unfortunately, unless you’re in need of a blood transfusion, this information isn’t readily available to UK patients. So, it’s not that accessible. However, if you do know your blood type, Dr d’Adamo recommends the following:

  • For O types, your blood dates back to hunters. You should feel better on a high protein diet. It's basically paleo.

  • Blood types A are “agrarians” or “cultivators”. Their body responds better to a high plant based diet free from red meat. In other words, a vegetarian diet.

  • Blood types B are so called “n­omads”. They tend to have a strong immune system and flexible digestive system that can tolerate dairy. Apparently, they’re the only blood type that can.

  • Finally, there’s blood type AB. Those of us with both A and B type parents that lent us a gene each. AB types are “The Enigma.” Dr d’Adamo believed that good foods for AB types are unknown.

In your professional opinion, would you ever recommend it?

Absolutely not. Sadly, there just isn’t enough science backing Dr d’Adamo’s theories, not to mention the impracticalities and holes in it. The diet dates back to 1996. I can’t help but think that if the claims were true there would be a body of scientific research backing it by now. As far as I know, there isn’t.

Monkey eating a banana. Photograph by Jeremy Bishop.

What’s more is, a lot of the principles in the diet just don’t stand up. It casts some serious doubts on its credibility. Take the theory of how our blood types adapted for example. It implies that ABO blood types are unique to humans and that they evolved through certain adaptations- i.e. A types evolved from agriculture and B types evolved from dairy consumption. This can’t be accurate. ABO blood types exit in various primates like gorillas and orangutans as well as other species too. None of which have changed their diets over millions of years for them to adapt. I can’t help but think that if there were some truth to the claims, then we’d see monkeys cultivating cereal grains and gorillas milking cows for dairy. This is obviously not the case! Not to mention that in my clinic I’ve seen a couple of type B clients who have tested positive to dairy intolerance.

I really could go on, but the most fundamental reason why I wouldn’t recommend it to my clients is that it is very impractical. For households that consist of multiple blood types, organising dinner would be a logistical nightmare.

Is there anyone who should avoid it?

I think dietary changes should be based on scientific evidence. Ultimately, food is information and whatever we choose to put in our mouths or eliminate from our diets will have either a positive or negative biochemical bearing on our health. It is really that simple. That is why it is so important to ensure that your diet is right and safe for you; it should be science that guides that. Diets that lack evidence to back their claims should be avoided in general. This includes The Blood Type Diet.

"There just isn’t a one size fits all diet."

What would you consider a better alternative (if you think there is one)?

I’m afraid to say, there just isn’t a one size fits all diet. A better alternative to eating well would be to follow a functional medicine approach to health. It is about personalised nutrition because no two people are ever the same; not even identical twins. Functional Medicine views your body through a wide camera lens. Symptoms, health concerns or dietary needs are seen in the broader context of your lifestyle, environment, genetics, current diet, medical history and total body systems. This way you can work out which scientifically proven foods you should add into your existing diet to help you thrive. But it need not be complicated. It’s a good idea to work with a Registered Nutritional Therapist as we can help you work out what those foods are how to upgrade your lifestyle so that it feels easy.

If I were to share one piece of advice that would work for everyone it would be to eat as closely to your great, great, great grandmother’s diet. I have to say the Blood Type Diet isn’t too far off in this regard. One thing that I do like about it, is that it ultimately promotes a way of eating that is ancestral. In other words, eating more wholesome, organic and unprocessed foods. Anyone should feel better making at least this change.

Kay Ali, Registered Nutritional Therapist & Co Founder of You Need A Nutritional Therapist

Featured Posts

In partnership with You Need A Vicky & You Need A PA

Business operates in London.

Registered address: 1 Gordon Road, Richmond-Upon-Thames, TW9 2EG

Company 10581246

© Copyright © 2019 by You Need A Nutritional Therapist Ltd.  All rights reserved. 

Our clinic is accredited and registered with: