That is according to researcher Dr Karin Ried, whose study was published in medical journal Maturitas.
Doctor Ried said: "When we gave [patients] this garlic supplement we were able on average to reduce their blood pressure under the hypertension threshold."
She said that the results of the research suggested that "garlic might be a good complementary treatment" for those suffering from high blood pressure.
This was significant, she said, as reduced blood pressure could cut the chances of a person developing cardiovascular disease.
Patients who suffer from high blood pressure and fail to get it treated and are also obese have a higher risk of having a heart attack, the BBC states.
Other risk factors for coronary disease, the website suggested, include patients who have hypertension in conjunction with raised blood cholesterol levels or diabetes.