Can Your Blood Type Predict Your Risk of Virus Infection?

Reproduced from original article:
Analysis by Dr. Joseph Mercola    Fact Checked
June 27th 2020

blood type and covid-19 infection


  • The results from three studies show that blood type O has some protective effect against COVID-19; one scientist believes the factor is small compared to comorbidities
  • The authors of one study tested genetic variants and found the gene responsible for overreaction of the immune system was near the gene for blood type
  • Some have used at-home DNA testing to track genealogy or learn about medical risks; while helpful for this, using consumer labs is not risk-free
  • Your blood type is likely not the most important factor; instead, optimize your vitamin D level, improve your metabolic sensitivity and reduce insulin resistance with intermittent fasting

Not soon after China revealed the discovery of SARS-CoV-2 in their country, scientists around the world began acting. This was a different type of coronavirus than had been studied since at least 1980.1

One difference is the gain of function potential capabilities the virus is believed to have2 that have been used in lab settings to alter the function of cells “as powerful tools to understand basic bacterial and viral biology and pathogen-host interactions.”3 The U.S. had banned this research in 2014, but in 2017 it was quietly lifted and4

“… the US National Institutes of Health (NIH) announced that they would resume funding gain-of-function experiments involving influenza, Middle East respiratory syndrome coronavirus, and severe acute respiratory syndrome coronavirus [SARS].”

The novel coronavirus appeared to trigger a wide range of symptoms in people. Some had only a mild affliction; others were sick for weeks and still others suffered such serious respiratory debilitation that they required the assistance of a ventilator.5

Your Blood Type May Reveal Risk Profile

After the SARS outbreak of 2003, researchers found that one specific blood type, Type O, had a potential protective effect against that strain of the coronavirus.6 Scientists have also been looking at what genetic factors may impact infection and its severity for people exposed to SARS-CoV-2.

The home-based genetic testing company 23andMe released preliminary results from a study they conducted using the information of more than 750,000 people.7 Their early results suggest that a person’s blood type has an influence on their susceptibility to the virus.

In addition to the information they used from among the millions who have sent their DNA to the company,8 they want to add data from 10,000 hospitalized patients who are not already part of their database.9

The company reported that the percentage who tested positive for COVID-19 by blood type was 4.1% for blood group AB.10 The differences reported in the study showed that those with type O had a 9% or 18% lower potential for testing positive for the virus when compared to those with blood types A, B or AB.11

In a separate study, researchers found that individuals with blood type O Rh positive had the best protection.12 23andMe did not find any differences between the two RH factors, positive or negative.13 It’s important to note that data were collected from self-reported information, which may reduce the validity of this study.14

In an investigation from China, researchers compared the blood types of 2,173 patients who tested positive for SARS-CoV-2.15 The results demonstrated that those with blood type O had a lower risk of infection and those with blood type A had a higher risk. The results of this study are early, and the researchers warn they should be used only as a guide.

A different group of researchers evaluated the health information of people who had respiratory failure; in addition to reviewing the data from a control group, they studied individuals who were patients at seven hospitals in Italy and Spain.16 In the final analysis, 835 people from Italy and 775 people from Spain who tested positive for the virus were included.

The researchers analyzed 8.5 million single-nucleotide polymorphisms, which are genetic variations.17 They found statistically significant genetic differences in blood groups. They also found a higher risk for individuals who have A-positive blood and a lower risk for those with blood type O.

It’s important to remember that the results do not demonstrate there is absolute protection or risk with blood type, only that those with blood type O may have a lower risk and those with blood type A may have a slightly higher risk. The results from Italy and Spain add to a growing body of evidence indicating that blood type has some impact on a person’s susceptibility to the SARS-CoV-2 infection.18

Laura Cooling from the University of Michigan said that the current data don’t match the epidemiology of the disease pattern in the U.S.19 She pointed out that blood type O is more prevalent in the population of African-Americans, who are experiencing a disproportionately higher number of infections.

This suggests that blood type may be less of a risk factor compared to others, such as comorbidities known to increase the risk of severe conditions and disease such as vitamin D deficiency, obesitydiabetes and cardiovascular diseases.20


Click here to learn Dr. Mercola's top tips to combat coronavirus

What’s Important About Blood Type?

Blood type has an impact on emergency care and transfusion; a successful transfusion requires that the person receiving the blood gets the same type from a donor.

Your blood type is determined by the presence or absence of antigens on the surface of every red blood cell. These give your blood specific characteristics, including blood type. The four major types that are determined by two specific antigens, A and B, include A, B, AB and O. Another factor, Rh, may also be present.

The most common blood types are O-positive and A-positive. The approximate distribution of blood types ranges from type O-positive at 38% of the population to type AB-negative at 1% of the population.21

At this time, it’s not understood how blood type may play a role in susceptibility to COVID-19. Professor Andre Franke from the University of Kiel is an author of the study from Italy and Spain.22 He found the gene to type blood is near a gene that controls a protein for a strong immune response.

The overreaction of the immune system, called a cytokine storm, is primarily what causes a massive inflammatory response and lung damage with COVID-19. Theoretically, this genetic variation may have an influence over the immune system and explain the link to blood type.

Consider These Risks Before Taking a Home DNA Test

The number of people using at-home DNA tests to track their ancestry, confirm their heritage or get information on blood type grew through 2019, as demonstrated by the large population that 23andMe used in their study.23,24

Although saw recent growth, that company, along with, which also collects your DNA, began losing sales in 2019. However, these tests are not risk-free. They still hold the data on everyone who’s sent them information, however.25 The potential use for DNA ranges from mapping your family tree and helping find genetic indicators to identifying health conditions and solving crimes.

The last two are usually done in highly regulated labs, while DNA to identify your family tree is not. The at-home test kit allows you to check your results online.26 In so doing, you have to give the company permission to store your information in their database. This is the same database 23andMe used to perform the recent comparison of blood type and COVID-19 infection.

Information may also be used in other ways, depending on the rules of the company. With some, your use of their services allows them to sell your genetic data to third parties without your consent and without profit sharing. Pharmaceutical companies, as an example, need large DNA data sets to develop new drugs.

These data are typically sold for millions of dollars, but those who provide the data realize none of the profits.27 That irony is compounded by the fact that consumers have to pay about $99 to get their DNA tested, which then becomes freely available for corporate use and profiteering, among other things, over which the donors have no control.

Your DNA is your most personal set of information, which can be used and manipulated in several ways. In an era when companies have difficulty keeping your usernames and passwords safe, it isn’t unrealistic to think your DNA data may also be at risk.

In 2013 researchers published a paper demonstrating that it was possible to identify people participating in genetic research studies by cross-referencing their data with information freely available on the internet.28,29 Scientists are excited about the potential information that may be gleaned from large DNA databases, but it poses a problem for your privacy.

Direct-to-consumer DNA testing companies are not bound by HIPAA regulations, which means your personal health information is not protected.30 Even if there is no leak, your genetic information may be used by employers, life insurance organizations and health insurance companies. In fact, in 2013, 23andMe admitted that the goal of their company was to collect massive amounts of DNA data to use without donors’ consent.31

Steps to Optimize Your Health and Support Your Immune System

It is helpful to know your blood type, but that is likely not a strong factor in your ability to withstand a viral infection. The number of people who are dying from COVID-19 lies somewhere between the World Health Organization’s estimate of 3.4%32 and a study in Nature Medicine indicating 1.4%.33

With many cases going unreported or untested, many of the mild and asymptomatic cases are likely not included in the figures. This means the death rate would be lower. In a study from Italy’s national health authority, 99% of the deaths in Italy were in people who had underlying medical conditions.34

Of those reported, 48.5% had 3 or more comorbidities.35 This points to the importance of addressing any underlying conditions you may have. It’s important that you work to optimize your health in ways that don’t also result in unwanted side effects or conditions related to taking a drug.

Comorbid conditions with higher rates of death and severity are cardiovascular disease, diabetes, high blood pressure, chronic respiratory diseases and cancer.36 Of the five conditions in this list, four are significantly affected by metabolic dysfunction. The common denominator is insulin resistance, which is triggered by a diet of high amounts of carbohydrates and processed foods.

When your body is insulin resistant it is also not metabolically flexible. As Dr. Sandra Weber, president of the American Association of Clinical Endocrinologists, noted:37

“We know that if you do not have good glucose control, you’re at high risk for infection, including viruses and presumably this one [COVID-19] as well … [improving glucose control] would put you in a situation where you would have better immune function.”

What and when you eat has a strong influence on your ability to beat insulin resistance. Intermittent fasting promotes insulin sensitivity and improves blood sugar management. This strategy helps to resolve Type 2 diabetes, high blood pressure, obesity and other conditions affected by metabolic dysfunction. To read more about how intermittent fasting affects insulin sensitivity, see “Intermittent Fasting Instead of Insulin for Type 2 Diabetes.”

Researchers have also found compelling evidence that maintaining optimal levels of vitamin D helps to lower your risk of severe disease. Since scientists anticipate a second wave of illness in the fall, you have a known “deadline” to raise your vitamin D level to at least 60 ng/mL and up to 80 ng/mL by that time.

Importantly, research published April 28, 2020 showed vitamin D insufficiency is prevalent in severe cases of COVID-19.38 They also found 100% of people under age 75 admitted to the intensive care unit had vitamin D insufficiency. For a more in depth discussion of how your vitamin D level will impact your risk and how to optimize your levels see “Your Vitamin D Level Must Reach 60ng/mL Before the Second Wave.”

So, how do you go about optimizing your vitamin D level? First, you need to find out what your base level is, which is done using a simple blood test. An easy and cost-effective way of doing this is to order GrassrootsHealth’s vitamin D testing kit.

Once you know what your blood level is, you can assess the dose needed to maintain or improve your level. Again, the ideal level you’re looking for is above 40 ng/mL, and ideally between 60 ng/mL and 80 ng/mL (European measurement: 100 nmol/L or, ideally, 150 nmol/L to 200 nmol/L).

Next, you can fine-tune your dosage further by taking into account your baseline vitamin D level. To do that, you can either use the chart below, or use GrassrootsHealth’s Vitamin D*calculator. To convert ng/mL into the European measurement (nmol/L), simply multiply the ng/mL measurement by 2.5.

Along with intermittent fasting and optimizing your vitamin D levels, you’ll find a list of more strategies you can simply incorporate into your daily routine at “Want to Defeat Coronavirus? Address Diabetes and Hypertension.”

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