Researchers found that certain herbs and plants commonly used in Mediterranean diets can help protect against cardiovascular diseases. (alicja neumiler/Shutterstock)
In a nutshell
- Six Mediterranean plants—garlic, hawthorn, saffron, olive, rosemary, and grape—contain powerful compounds that work together to lower blood pressure, reduce inflammation, improve cholesterol, and protect blood vessels. Their multitargeted effects mimic some drug mechanisms but with fewer side effects when consumed as part of a healthy diet.
- The real strength of the Mediterranean diet may lie in how these foods interact. Pairings like olive oil with leafy greens or garlic with fatty fish could boost heart health more than individual ingredients alone, an effect researchers call the “matrix effect.”
- While early research looks promising, many clinical trials are still small or short-term. The scientists call for more human studies to better understand ideal dosages, long-term safety, and how these natural compounds work together in real-life diets.
CERDANYOLA DEL VALLÈS, Spain — What you eat every day can help or hurt your heart health. New research reveals that six humble plants from Mediterranean kitchens contain powerful compounds that fight cardiovascular disease from multiple angles. Scientists have now mapped precisely how garlic, hawthorn, saffron, olive, rosemary, and grape combat the world’s biggest killer through mechanisms that pharmaceutical companies often try to replicate in labs.
A team of scientists from Spain, Chile, and Cuba recently examined six common Mediterranean plants and found compelling evidence that their natural compounds fight cardiovascular disease. Published in Food Bioscience, this study looks at garlic, hawthorn, saffron, olive, rosemary, and grape – staples of Mediterranean cuisine that have been used medicinally for centuries. By analyzing both traditional knowledge and modern research, the scientists mapped out how compounds in these plants work to protect cardiovascular health.
Heart disease isn’t slowing down. It accounts for about one-third of global deaths. While pharmaceutical approaches dominate treatment, plants offer complementary or alternative options that may have fewer side effects when properly used. The challenge has been understanding exactly how these natural compounds work and establishing standardized approaches to their use.
The Mediterranean Six
Following a Mediterranean diet has been linked to so many health benefits. This study, however, points to six specific plants that can boost your heart health. So, what makes these ingredients so special?
Garlic contains compounds like diallyl trisulfide, allicin, and S-allyl-cysteine that do more than just flavor your food. When allicin converts to hydrogen sulfide in the body, it relaxes blood vessels, helping lower blood pressure. Other garlic compounds fight inflammation and activate antioxidant pathways that may slow down atherosclerosis (hardening of the arteries). Previous studies show garlic supplements can significantly reduce blood pressure in people with hypertension and improve cholesterol levels.
Hawthorn might not be as familiar to American diners, but this Mediterranean shrub contains compounds that fight inflammation and oxidative stress (quercetin, apigenin, and chlorogenic acid). Quercetin works similarly to certain blood pressure medications by inhibiting an enzyme involved in blood vessel constriction. Chlorogenic acid helps clear free radicals from the body and may reduce cholesterol and triglyceride levels by affecting key enzymes.
Saffron, which you may know as that expensive spice that gives paella its distinctive color, contains crocin and safranal, which have shown remarkable antioxidant properties. Safranal helps relax blood vessels by affecting calcium channels in muscle cells. Studies found that saffron supplements can improve cholesterol levels and lower blood pressure.
Olive is the foundation of Mediterranean cooking, and for good reason. Its compounds work through numerous pathways to protect heart health. They prevent LDL cholesterol from oxidizing (a key step in arterial plaque formation), reduce inflammation, and help lower blood pressure. Multiple clinical trials confirm that olive leaf extract and olive oil improve both blood pressure and lipid profiles.
Rosemary contains rosmarinic acid and carnosic acid, which fight oxidative damage and inflammation. Rosmarinic acid can help lower blood pressure and relax blood vessels, at least in animal studies.
Grape skin contains resveratrol, which reduces oxidative stress, increases nitric oxide (which helps blood vessels relax), and affects lipid metabolism. Studies show grape seed extract can significantly reduce blood pressure and heart rate.
Beyond Single Ingredients: The Power of Combination
People living in Mediterranean regions have consumed these plants for centuries, but now we’re learning exactly why they protect the heart so effectively. Unlike many medications that target a single pathway, natural compounds can simultaneously fight different factors in cardiovascular disease development.
For example, compounds in olive oil help lower blood pressure and prevent LDL cholesterol from becoming more dangerous through oxidation. Garlic both relaxes blood vessels and inhibits inflammation. Each of these super plants is multitasking, which might explain why the Mediterranean diet as a whole shows such strong cardiovascular benefits.
Combining these foods might also amplify their benefits. Olive oil paired with leafy greens may boost nitric oxide production more than either alone. Garlic consumed with fatty fish could enhance both their triglyceride-lowering and antioxidant effects.
Bringing These to Your Table
If you want to implement these ingredients more regularly into your eating habits, the researchers suggest consuming certain amounts of each daily. They recommend aiming for 25-40 mL (about 2-3 tablespoons) of extra virgin olive oil, incorporating 300-2600 mg of garlic (roughly 1-8 cloves), using rosemary regularly as a culinary spice (2-6 g daily), and enjoying fresh grapes (330-500 g, or about 2 cups) or grape products. Saffron can be included at 100-400 mg daily, though its expense often limits frequent use.
The Mediterranean diet clearly offers a time-tested approach to heart health, with these six plants playing star roles. Incorporating these plants into our diets, whether through fresh foods or standardized supplements (with healthcare provider guidance), may help address the continuing crisis of cardiovascular disease.
Paper Summary
Understanding the Methods
Rather than conducting new experiments, the researchers gathered and analyzed existing knowledge. They searched scientific databases like PubMed, Web of Science, and Scopus for relevant studies, selecting the most reliable publications based on preliminary assessments of titles and abstracts. They also used a technique called co-citation analysis, examining the references in important papers to find additional relevant research. This approach helped them compile findings from 211 scientific papers. The plants they studied weren’t randomly chosen – each had to meet specific criteria: they needed to be traditionally used in Mediterranean cooking, native to the Iberian Peninsula, show proven cardiovascular benefits, and contain specific active ingredients that could be linked to these benefits. The researchers focused on understanding how these plant compounds work in the body, what clinical studies show about their effects, and any potential side effects.
Results Summary
Each plant in the study contains specific compounds that protect heart health in different ways. Garlic compounds help blood vessels relax by promoting production of hydrogen sulfide and nitric oxide, while also reducing cholesterol by blocking enzymes involved in its production. Hawthorn contains quercetin, which works like some blood pressure medications, and apigenin, which fights inflammation. Saffron’s compounds act as powerful antioxidants and help relax blood vessels, with clinical studies showing improvements in cholesterol and blood pressure. Olive compounds protect against LDL cholesterol oxidation (a key step in heart disease), reduce inflammation, and lower blood pressure through multiple mechanisms. Several human studies confirm that olive products improve blood pressure and cholesterol profiles. Rosemary compounds fight oxidation and inflammation while helping relax blood vessels by activating potassium channels. Grape’s resveratrol activates several protective pathways that reduce oxidative stress and increase nitric oxide, with clinical studies showing it can significantly lower blood pressure.
Study Limits
The researchers point out several gaps in our current knowledge. Many plant extract studies lack standardization, making comparisons difficult. Information about long-term safety when used as supplements (rather than foods) remains limited. The researchers note that we don’t fully understand how these compounds might work together when consumed as part of a complete Mediterranean diet – the “matrix effect” might enhance their benefits in ways we don’t yet comprehend. Many clinical trials had small participant numbers and short durations, weakening the strength of evidence. The researchers also acknowledge that while these plants show promise, there’s not enough evidence yet to recommend specific therapeutic dosages. Many studies were conducted in lab settings or animal models rather than humans, limiting their immediate applicability. Finally, they emphasize that “natural” doesn’t automatically mean “safe,” highlighting the need for proper studies of how these compounds behave in the body, their potential toxicity, and clinical effects.
Key Takeaways
The research shows these Mediterranean plant compounds protect heart health through four main mechanisms: fighting oxidative stress (both directly and by activating the body’s own antioxidant systems), reducing inflammation by blocking pathways like NF-κB, promoting blood vessel relaxation by increasing nitric oxide and affecting calcium channels, and regulating fat metabolism by influencing cholesterol production and transport. For practical application, the researchers suggest an optimal heart-healthy Mediterranean diet should include olive oil (25-40 mL daily), garlic (300-2600 mg daily), rosemary (2-6 g daily), saffron (100-400 mg daily), and grape products (equivalent to 330-500 g of fresh grapes). They note that certain food combinations might work better together – like olive oil with leafy greens to boost nitric oxide, or garlic with omega-3-rich fish to enhance their complementary benefits. The researchers suggest this integrated approach captures the essence of the Mediterranean diet’s synergistic benefits rather than focusing on isolated compounds. They emphasize the need for more research to better understand these interactions and determine optimal amounts when foods are combined.
Funding Information
This research received support from the “María Zambrano” Grant Program provided by the Ministry of Universities of Spain and the Universitat Autonoma de Barcelona (Reference code: MZ2021 34), with funding from the European Union. The work served as Mateu Anguera-Tejedor’s Final Degree Project in Biology at the Autonomous University of Barcelona. The authors declared no competing financial interests or personal relationships that might have influenced their findings.
Publication Details
This review, “Exploring the therapeutic potential of bioactive compounds from selected plant extracts of Mediterranean diet constituents for cardiovascular diseases: A review of mechanisms of action, clinical evidence, and adverse effects,” appeared in Food Bioscience (Volume 62, 2024, Article 105487). The author team included Mateu Anguera-Tejedor, Gabino Garrido, Barbara B. Garrido-Suárez, Alejandro Ardiles-Rivera, Angel Bistué-Rovira, Francesc Jiménez-Altayó, and René Delgado-Hernández from institutions across Spain, Chile, and Cuba. The paper was submitted in July 2024, accepted in November 2024, and published online shortly thereafter.
“Hawthorn might not be as familiar to American diners, but this *Mediterranean* shrub…”
What? Are we talking about a Crataegus species? Hawthorn grows around the world, including species native to non-Mediterranean Europe, China, and North America.
What part of the hawthorn plant supplies the anti-inflammatory compounds noted? Do other species supply those compounds as well?
It might be helpful to include the scientific name for generic plant names that are found around the globe.