Do blood type and diet attract mosquitoes

Short answer

The popular claims are mostly weak or unproven. You have probably read that type O blood is a mosquito magnet, that eating bananas turns you into a target, or that garlic and vitamin B pills will keep the bugs away. When you trace those claims back to the actual research, most of them rest on a handful of small studies, mixed results, or no controlled evidence at all.

What the science does support is more boring and more useful. Mosquitoes find and choose people mainly through the carbon dioxide you exhale, the heat your body gives off, and the specific blend of odor compounds on your skin. Blood type and diet, if they matter at all, sit far down the list. If you want to be bitten less, the reliable move is repellent and physical barriers, not a change to your grocery list.

Does blood type attract mosquitoes

This is the most repeated claim, and it is also one of the shakiest.

A small number of studies have looked at whether people with a particular ABO blood group get landed on more often. The most cited is a 2004 laboratory study of the Asian tiger mosquito (Aedes albopictus) with 64 volunteers. It reported that mosquitoes landed on blood group O people more than on group A people, with mean relative landing around 78 to 83 percent for group O secretors versus roughly 45 to 47 percent for group A (Source 1). On its face that looks like a clear O preference.

Read more carefully and the picture gets murky. The same authors were cautious about their own result, noting that the antigen tests they ran did not actually explain the landing pattern and that “there may be other unknown influences” behind the differences. The study used a small group, tested one mosquito species under close-range laboratory conditions, and did not settle why any preference would exist.

The broader literature on blood type and biting is thin and inconsistent. Different studies use different mosquito species, different methods, and small numbers of people, and they do not line up neatly into “type O gets bitten more.” So the honest summary is this: a few small studies hint that type O might be slightly more attractive, but the evidence is limited, the effect is not well explained, and it is nowhere near strong enough to predict who gets bitten at a backyard cookout. Your blood type is not something you can change anyway, which makes it a poor basis for any bite-prevention plan.

Does drinking beer attract mosquitoes

There is a bit more here, but still just one small study doing the heavy lifting.

In a 2010 experiment in Burkina Faso, researchers tested whether drinking beer changed how attractive people were to the malaria mosquito Anopheles gambiae. Volunteers drank either about one liter of dolo, a local sorghum beer of roughly 3 percent alcohol, or water, and their body odor was piped to mosquitoes in a Y-shaped choice tube. Beer drinkers became modestly more attractive: mosquito activation rose to about 47 percent after beer versus 35 to 38 percent otherwise, and orientation toward the human odor rose to about 65 percent versus roughly 50 percent (Source 2).

Two honest caveats. First, this is a single small study, with 25 beer drinkers and 18 water drinkers, using one African malaria species. Second, and importantly, the authors could not explain why it happened. They checked the obvious suspects and found that increased body temperature and exhaled carbon dioxide did not account for the effect. They could only speculate that metabolizing alcohol shifts the odor compounds you give off. So “beer makes you a bit more attractive to one mosquito species in one experiment” is a fair reading. “Alcohol reliably makes you a mosquito magnet” goes beyond what the data show.

Bananas, garlic, vitamin B, and other food myths

This is where folklore is strongest and evidence is weakest.

Bananas. A study published in 2018 tested whether eating a banana changed attraction of the malaria mosquito Anopheles stephensi, using hand odor from volunteers. One hour after eating a banana, mosquito contacts went up compared to before eating, while green grapes produced no effect (Source 3). That is a real, measurable result, so bananas are not pure myth. But the same paper is candid about its limits: counts were self-reported and unblinded, only hand odor was tested rather than the whole body, only close-range attraction was measured, not every person responded the same way, and only two Anopheles species were used. It is a single narrow study, not proof that skipping bananas will spare you from bites.

Garlic. The idea that eating garlic wards off mosquitoes has been tested directly. A 2005 randomized, double-blind, placebo-controlled trial had volunteers eat garlic or a placebo and then be exposed to Aedes aegypti. It found no meaningful systemic repellent effect on biting (Source 4). Eating garlic did not protect people.

Vitamin B. Vitamin B, especially B1 (thiamine), is one of the most common “natural repellent” claims online. A 2005 study specifically set out to test it as a home remedy, using a larger group of subjects than earlier work and the mosquito Anopheles stephensi. Despite large and consistent differences in how attractive individuals were, taking vitamin B made no difference (Source 5). Later reviews of thiamine as a repellent have reached the same unimpressed conclusion.

The pattern across these foods is consistent. Where good controlled studies exist, garlic and vitamin B do nothing, and bananas produce at most a small, narrowly measured bump. There is no dietary switch that reliably turns bites off.

What actually drives mosquito attraction

If diet and blood type are minor, what does the choosing? Three things do most of the work.

Carbon dioxide. Mosquitoes detect the CO2 in your breath and use it to locate a warm-blooded target from a distance. It is one of the first cues that puts you on their radar (Source 6).
Body heat and moisture. Once close, mosquitoes home in on the warmth and humidity coming off your skin. Heat becomes a much stronger draw once CO2 has switched their host-seeking on (Source 6).
Skin odor. At short range, the specific chemical blend on your skin decides who gets bitten. A 2022 study found that people who are consistently more attractive to Aedes aegypti produce much higher levels of carboxylic acids, oily compounds tied to skin and to the bacteria living on it. Those levels stayed stable in the same people for a year or more (Source 7). Your skin chemistry, shaped largely by your body and its microbes, is a far bigger factor than what you ate for lunch.

For a fuller breakdown of individual differences, including sweat, skin bacteria, pregnancy, and clothing color, see the companion page Why some people get bitten more than others (Related, below).

The takeaway

Do not build your bite-prevention plan around your diet or your blood type.

Blood type: a few small studies hint at a slight type O preference, but the evidence is limited, inconsistent, and unexplained. You cannot change it anyway.
Beer: one small study found a modest increase in attractiveness to one mosquito species, with no clear mechanism.
Bananas: one narrow study found a small short-term bump. Garlic and vitamin B show no benefit in controlled tests.
What actually matters: carbon dioxide, body heat, and skin odor, which are largely outside your control.

The dependable defense is well established: use an EPA-registered repellent such as DEET, picaridin, or oil of lemon eucalyptus, wear long sleeves and pants when mosquitoes are active, and remove standing water where they breed. Those steps work regardless of your blood type or last night’s dinner.

Sources

Shirai, Y., et al. (2004). “Landing Preference of Aedes albopictus (Diptera: Culicidae) on Human Skin Among ABO Blood Groups, Secretors or Nonsecretors, and ABH Antigens.” Journal of Medical Entomology, 41(4), 796 to 799. Primary source for the type O landing result and the authors’ own caution that it is not well explained. https://academic.oup.com/jme/article/41/4/796/885285 (accessed 2026-07-20)
Lefèvre, T., et al. (2010). “Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes.” PLOS ONE, 5(3): e9546. Primary source for the beer experiment, the activation and orientation percentages, and the statement that the mechanism is unclear. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0009546 (accessed 2026-07-20)
Paskewitz, S., et al. (2018). “Impact of Consumption of Bananas on Attraction of Anopheles stephensi to Humans.” Insects, 9(4), 129. Primary source for the banana result and its stated limitations. https://pmc.ncbi.nlm.nih.gov/articles/PMC6315685/ (accessed 2026-07-20)
Rajan, T.V., et al. (2005). “A double-blinded, placebo-controlled trial of garlic as a mosquito repellant: a preliminary study.” Medical and Veterinary Entomology, 19(1), 84 to 89. Controlled trial finding no systemic garlic repellent effect. https://resjournals.onlinelibrary.wiley.com/doi/10.1111/j.0269-283X.2005.00544.x (accessed 2026-07-20)
Ives, A.R., and Paskewitz, S.M. (2005). “Testing Vitamin B as a Home Remedy Against Mosquitoes.” Journal of the American Mosquito Control Association, 21(2), 213 to 217. Found no effect of vitamin B on attractiveness. https://pubmed.ncbi.nlm.nih.gov/16033124/ (accessed 2026-07-20)
Caltech News, “Mosquitoes Use Smell to See Their Hosts” and NIH MedlinePlus Magazine, “How mosquitoes tell the difference between animal and human hosts.” Plain-language summaries of primary research showing carbon dioxide, heat, and skin odor as the core host-seeking cues. https://www.caltech.edu/about/news/mosquitoes-use-smell-see-their-hosts-47338 and https://magazine.medlineplus.gov/article/how-mosquitoes-tell-the-difference-between-animal-and-human-hosts-and-why-it-matters (accessed 2026-07-20)
De Obaldia, M.E., et al. (2022). “Differential mosquito attraction to humans is associated with skin-derived carboxylic acid levels.” Cell, 185(22), 4099 to 4116. Primary source for skin carboxylic acids and stable individual attractiveness. NIH summary: https://www.nih.gov/news-events/nih-research-matters/skin-compounds-associated-attractiveness-mosquitoes and journal article: https://www.cell.com/cell/fulltext/S0092-8674(22)01263-6 (accessed 2026-07-20)

Why some people get bitten more than others [placeholder link: /bites/why-some-people-bitten-more]
How mosquitoes find you: carbon dioxide, heat, and odor [placeholder link: /bites/how-mosquitoes-find-you]
Choosing an effective mosquito repellent [placeholder link: /prevention/repellents]

Educational note: This page summarizes published research for general information and is not medical advice. Study results on individual attractiveness are averages and do not predict any one person’s experience. For protection from mosquito-borne illness, follow guidance from your local health authority and use EPA-registered repellents as directed.

Last reviewed 20 July 2026.