Have you heard of the blood type diet? I thought it had been debunked long ago but patients keep asking about it, so I figured I should learn more.
What’s the Blood Type Diet?
In 1996 Peter D’Adamo, a naturopathic physician, published a book in which he described how people could be healthier, live longer, and achieve their ideal weight by eating according to their blood type. One’s choice of condiments, spices, and even exercise should depend on one’s blood type. Soon, the book was a best seller and people everywhere were finding out their blood type, revising their grocery lists, and changing how they ate, exercised, and thought about their health.
Here are some of the recommendations according to the “Eat Right for Your Type” diet:
- Those with type O blood should choose high-protein foods and eat lots of meat, vegetables, fish, and fruit but limit grains, beans, and legumes. To lose weight, seafood, kelp, red meat, broccoli, spinach, and olive oil are best; wheat, corn, and dairy are to be avoided.
- Those with type A blood should choose fruit, vegetables, tofu, seafood, turkey, and whole grains but avoid meat. For weight loss, seafood, vegetables, pineapple, olive oil, and soy are best; dairy, wheat, corn, and kidney beans should be avoided.
- Those with type B blood should pick a diverse diet including meat, fruit, dairy, seafood, and grains. To lose weight, type B individuals should choose green vegetables, eggs, liver, and licorice tea but avoid chicken, corn, peanuts, and wheat.
- Those with type AB blood should eat dairy, tofu, lamb, fish, grains, fruit, and vegetables. For weight loss, tofu, seafood, green vegetables, and kelp are best but chicken, corn, buckwheat, and kidney beans should be avoided.
As mentioned, the recommendations for the blood type diets extend well beyond food choices. For example, people with type O blood are advised to choose high-intensity aerobic exercise and take supplements for their sensitive stomachs, while those with type A blood should choose low-intensity activities and include meditation as part of their routine.
But does eating for your blood type work?
High-quality studies about the blood type diet had not been published in peer-reviewed medical literature. Even now, a search in the medical literature for the author’s name reveals no research pertaining to this diet. Studies published in 2013 and 2014 about the blood type diets are worth noting. The 2013 study analyzed the world’s medical literature and found no studies demonstrating benefit from a blood type diet. The 2014 study found that while people following any of the blood type diets had some improvement in certain cardiometabolic risk factors (such as cholesterol or blood pressure), those improvements were unrelated to blood type.
Does it make any sense?
The theory behind this diet is that blood type is closely tied to our ability to digest certain types of foods, so that the proper diet will improve digestion, help maintain ideal body weight, increase energy levels, and prevent disease, including cancer and cardiovascular disease.
Type O was said to be the original “ancestral” blood type of the earliest humans who were hunter-gatherers, with diets that were high in animal protein. Group A was said to evolve when humans began to farm and had more vegetarian diets. Group B blood types were said to arise among nomadic tribes who consumed a lot of dairy products. And since Group AB blood was supposed to have evolved from the intermingling of people with types A and B blood, type AB recommendations were intermediate between those for people with types A and B blood.
Each of these theories has been challenged. For example, there is evidence that type A was actually the first blood group to evolve in humans, not type O. In addition, there is no proven connection between blood type and digestion. So, in addition to a lack of evidence that the diet works, serious questions remain about why it should work in the first place.
So, what’s the downside?
It’s a fair question, especially since some improvements were seen in people who adopted certain blood type diets (see link above). Eating based on your blood type requires you to know your blood type and then follow a restrictive diet. Personal preferences might be a problem: a vegetarian with type O blood may struggle to stay on the assigned diet, and people who love red meat may be disappointed to learn they have type A blood. Recommended supplements are not cheap; neither are the recommended organic foods. And if you have certain health conditions, such as high cholesterol or diabetes, a nutritionist can make better evidence-based recommendations for you than those determined by your blood type.
Advocates of blood type diets may say that while the ideal study has not yet been performed, the absence of evidence doesn’t prove they’re ineffective. And there’s also no proof that these diets are harmful. So, my guess is that interest in the blood type diets will not disappear any time soon. But there’s a reason that bookstores have rows and rows of books on diet, each claiming to be highly effective if not the best. We simply don’t know which diet is best for each individual person. And even if we did, sticking to any single diet is often challenging.
Stand by — it’s likely you’ll soon be hearing about yet another best diet. And my guess is that it won’t have anything to do with your blood type.
Bible verses for today’s meditation and inspiration: Matthew E. McLaren
1 Corinthians 3:1-2 And I, brethren, could not speak to you as to spiritual men, but as to men of flesh, as to infants in Christ. I gave you milk to drink, not solid food; for you were not yet able to receive it. Indeed, even now you are not yet able
,1 Corinthians 13:11 When I was a child, I used to speak like a child, think like a child, reason like a child; when I became a man, I did away with childish things.
1 Corinthians 14:20 Brethren, do not be children in your thinking; yet in evil be infants, but in your thinking be mature.
Psalm 65:9 You visit the earth and cause it to overflow; You greatly enrich it; The stream of God is full of water; You prepare their grain, for thus You prepare the earth.
2 Thessalonians 1:3 We ought always to give thanks to God for you, brethren, as is only fitting, because your faith is greatly enlarged, and the love of each one of you toward one another grows ever greater;
Proverbs 1:5 A wise man will hear and increase in learning, And a man of understanding will acquire wise counsel,
Acts 12:24 But the word of the Lord continued to grow and to be multiplied.
Proverbs 11:24 There is one who scatters, and yet increases all the more, And there is one who withholds what is justly due, and yet it results only in want.
Ezekiel 8:6 And He said to me, “Son of man, do you see what they are doing, the great abominations which the house of Israel are committing here, so that I would be far from My sanctuary? But yet you will see still greater abominations.”
Ephesians 4:16 from whom the whole body, being fitted and held together by what every joint supplies, according to the proper working of each individual part, causes the growth of the body for the building up of itself in love.
2 Chronicles 7:16 “For now I have chosen and consecrated this house that My name may be there forever, and My eyes and My heart will be there perpetually.
2 Corinthians 9:10 Now He who supplies seed to the sower and bread for food will supply and multiply your seed for sowing and increase the harvest of your righteousness;
Hebrews 5:12-14 For though by this time you ought to be teachers, you have need again for someone to teach you the elementary principles of the oracles of God, and you have come to need milk and not solid food. For everyone who partakes only of milk is not accustomed to the word of righteousness, for he is an infant. But solid food is for the mature, who because of practice have their senses trained to discern good and evil.
1 Peter 2:2 like newborn babies, long for the pure milk of the word, so that by it you may grow in respect to salvation,
Recommended contacts for prayer request and Bible study