Fresh-Pressed Olive Oil Club
EVOO and Health

Mediterranean Diet is Linked to Significant Reduction in Breast Cancer Risk

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Greatest effects among postmenopausal women

Closely following the Mediterranean Diet (MeDi), which emphasizes fruits, vegetables, whole grains, legumes, limited lean protein, and healthy fats such as olive oil and nuts, has been linked to a reduced risk of chronic diseases, including several forms of cancer. Numerous studies have shown associations between lower breast cancer risk in women and MeDi adherence. To clarify whether the the MeDi exerts a significant effect on breast cancer risk, researchers conducted a systematic review and meta- analysis that compiled and analyzed the existing evidence across a large international group of studies.

Methods: After a comprehensive literature search, 31 high-quality observational studies were selected for the final analysis (12 cohort studies and 19 case-control studies). Studies were published between 2006 and 2023 and conducted in the Americas, Europe, and Asia, with the majority in the United States and Spain. A total of 1,347,446 women were evaluated, grouped as overall, postmenopausal, and premenopausal. Participants’ ages ranged from 20 to 104 years. Follow-up duration varied between 8 and 33 years in cohort studies.

  • A cohort study is an observational study with an active group and control group, allowing researchers to calculate the occurrence of a disease in a population over time.
  • A case-control study identifies individuals with a specific disease or condition and assigns “matched controls”—people with the same demographic characteristics who are not part of the study—which enables researchers to evaluate the differences between these groups.

Results: The overall pooled analysis found a clinically significant 13% reduction in breast cancer risk in participants who adhered to the MeDi. The effect was greater in postmenopausal women across all studies and in participants of studies conducted in Asia. A subgroup analysis showed that moderate alcohol use (red wine) did not affect breast cancer risk in the overall group, but an additional reduction in breast cancer risk was seen in postmenopausal women.

Discussion: These results indicate that adherence to the MeDi may help prevent breast cancer, especially in postmenopausal women. It has been suggested that the polyphenols in olive oil and moderate amounts of red wine may contribute to the cancer-protective effects of the MeDi. In addition, phytoestrogens from vegetables and fruits may interact with the body’s estrogen production, thus helping to prevent certain types of breast cancer from developing. The sites of hormone production during the postmenopausal period (fat tissue rather than ovaries) may also account for the increased effect of the MeDi in preventing breast cancer in that population.

Conclusion: Adherence to the MeDi significantly reduced women’s breast cancer risk in a large meta-analysis of international observational studies involving more than a million participants. Future research will help identify the specific anti-cancer mechanisms of the MeDi and illuminate its varying effects across life stages and geographic regions.

Reference: Karimi M, Asbaghi O, Hooshmand F, et al. Adherence to Mediterranean Diet and Breast Cancer Risk: A Meta-Analysis of Prospective Observational Studies. Health Sci Rep. 2025;8(4):e70736.

Eating a Mediterranean-Style Diet Improved Brain Health in US Hispanic and Latino Adults

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Background: Cognitive decline—worsening memory and more frequent memory loss or confusion—affects 10% of all US adults aged 45 and older. Incidence is higher—11.4%—among Hispanic and Latino Americans. In some cases, cognitive decline may be an early sign of dementia.

Close adherence to the Mediterranean diet (MeDi) is associated with a reduced risk of dementia and cognitive decline. The MeDi emphasizes fresh fruits, vegetables, whole grains, beans, legumes, nuts, low to moderate amounts of dairy, eggs, fish, and poultry, and olive oil as the primary fat source.

Researchers have attributed the MeDi’s brain benefits to its cardiovascular effects, such as lower blood pressure, reduced diabetes risk, and improvements in blood vessel function and cholesterol levels. The first large-scale study of the MeDi in Hispanic and Latino Americans investigated whether the MeDi’s brain benefits are independent of its cardiovascular effects.

Preliminary findings from this 10-year study of 2,774 participants (44% men, 56% women; average age 64 at follow-up) were presented at the recent conference of the American Stroke Association, February 5–7, 2025.

Methods: At an initial visit, each participant reported their food intake during the previous 24 hours and received a score (0 to 9), indicating how closely their diet corresponded to the MeDi. Average MeDi score was 5. Ten years after the baseline visit, investigators obtained a brain scan via MRI (magnetic resonance imaging) for each participant.

The main outcome evaluated in the study was white matter integrity (WMI) and volume. The white matter of the brain (as opposed to the gray matter) consists of bundles of nerve fibers that, crucially, communicate information to different parts of the brain. WMI and volume are markers of the strength of those connections in the brain. MRI scans provide clear, detailed cross-sections of the brain, showing white matter and gray matter.

To account for the impact of cardiovascular benefits, the study also asked participants about multiple practices associated with heart health: regular exercise; healthy diet; not smoking; weight maintenance; and maintaining healthy blood pressure, blood sugar, and cholesterol levels.

Results: Participants with higher MeDi scores had stronger connections between regions of the brain (preserved WMI) compared to those with lower MeDi scores. With each point higher in MeDi score, participants’ MRI scans also showed less structural damage to the blood vessels of the brain. After factoring in heart-health practices, the researchers determined that cardiovascular effects alone did not account for all the significant brain benefits of the MeDi.

Conclusion: Eating a Mediterranean-style diet improved brain health and preserved structural integrity in a high-risk population. Even small adjustments in food intake, closer to the MeDi, could help protect against cognitive decline and dementia. The brain benefits of the MeDi extend beyond its well-known cardiovascular effects—more research is needed to identify the brain-protective mechanisms involved.

References: 1. Trifan G, Moustafa B, Issan C, et al. Stroke. 2025(56);Supp 1:Abstract 100. 2. Mediterranean-style diet linked to better brain health in older Hispanic and Latino Adults. February 5, 2025. 3. Wooten KG, McGuire LC, Olivari BS, et al. MMWR Morb Mortal Wkly Rep. 2023;72:249–255.

How EVOO Combats Heart Disease

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Part II: The Power of Polyphenols

A large body of evidence shows that daily consumption of EVOO can significantly reduce the risk of cardiovascular disease (CVD). Part I of this two-part series highlighted the contributions of oleic acid (OA). The other bioactive components of EVOO that protect against CVD are its more than 30 polyphenols.

Factors that contribute to CVD include oxidative stress, inflammation, cholesterol, blood-vessel function, and high blood pressure (hypertension). Below, we’ll look closely at the mechanisms by which polyphenols work in the body to modify and improve these factors.

What are polyphenols? Polyphenols are naturally occurring substances in many plants and fungi. Most polyphenols are antioxidants, which means they help neutralize chemical compounds formed in the body that can damage cells. Hydroxytyrosol (HT) has been identified as the polyphenol in EVOO that is essential in the prevention of CVD.

HT combats oxidative stress

Oxidative stress can cause cell mutations and has been identified as an underlying cause of multiple aspects of CVD. Injured tissues release ions—charged particles—that bind to oxygen, creating an excess of unstable molecules. As an antioxidant, HT directly neutralizes these unstable molecules, or reactive oxygen species (ROS). HT has also been shown to inhibit the cell damage produced by ROS and to enhance the antioxidant abilities of cells in the blood vessel walls.

Lowers inflammation

HT can block some of the processes that signal for cells to mount an inflammatory response. In this way, HT reduces the impact of inflammatory substances that are linked to oxidative stress as well as to impaired blood vessel function, a key risk factor for CVD.

Reduces “bad” cholesterol and improves “good”

Polyphenols reduce the amount of small molecules of LDL (“bad” cholesterol), which do the most damage. Polyphenols also help prevent LDL from forming plaques that build up in the arteries,
or atherosclerosis. In a 3-week clinical trial, HDL (“good” cholesterol) functioning improved significantly in healthy patients who consumed high-polyphenol EVOO, compared with low-polyphenol EVOO.

Protects the blood vessel lining and lowers blood pressure

Polyphenols help prevent damage to the endothelium, the inner lining of the blood vessel walls, by increasing the production of nitric oxide (NO), a vasodilator—a substance that relaxes the blood vessels. By enhancing the production of NO, polyphenols can improve endothelial function, protect against arterial stiffness, and lower blood pressure.

References: 1. Lu Y, Zhao J, Xin Q, et al. Food Science and Human Wellness. 2024;13:529-540. 2. Pandey KB, Rizvi SI. Plant polyphenols as dietary antioxidants in human health and disease. Oxid Med Cell Longev. 2009;2(5):270-278. doi:10.4161/oxim.2.5.9498 3. Lobo V, Patil A, Phatak A, Chandra N. Pharmacogn Rev. 2010;4(8):118-126. 4. Hernáez Á, Fernández-Castillejo S, Farràs M, et al. Arterioscler Thromb Vasc Biol. 2014;34(9):2115-2119.

How EVOO Combats Heart Disease

Posted on by The Olive Oil Hunter

Part I: a Primer on Oleic Acid (OA)

A large body of evidence shows that daily consumption of EVOO confers numerous health benefits, including a significantly reduced risk of cardiovascular disease (CVD).

Factors that contribute to CVD include cholesterol, inflammation, blood vessel function, insulin resistance, and high blood pressure (hypertension). The protective effects of EVOO are attributed to its bioactive components, oleic acid (OA) and more than 30 polyphenols.

In this concise review, we’ll look closely at the mechanisms by which OA works in the body to modify and improve these factors.

What is OA? Oleic acid is a monounsaturated fatty acid (MUFA) that makes up approximately 70 to 80 percent of EVOO by volume. MUFAs and PUFAs (polyunsaturated fatty acids) are the key components of liquid fats, such as vegetable oils and the fats in fish.

Lowers “bad” cholesterol and blood lipid levels: OA lowers LDL or “bad” cholesterol by increasing the amount of LDL that is removed from the blood by the liver and reducing the amount that is produced. In scientific terms, OA increases hepatic LDL receptor activity. Similarly, OA helps lower triglyceride levels by stimulating the liver to increase the breakdown and removal of the proteins that produce triglycerides.

Helps regulate blood pressure: After eating, we experience what is termed the postprandial reflex—a rise in blood triglycerides and increase in blood pressure. When OA enters cell membranes, signals are sent from the intestines to the blood vessels to release vasodilators, which relax the blood vessels, and to block the release of vasoconstrictors, which tighten the blood vessels and raise blood pressure.

Protects the blood vessel lining: Damage to the blood vessel lining (the endothelium) is a major risk factor for CVD. By stimulating the release of vasodilators, OA helps protect the endothelium. OA
also blocks signals from inflammatory proteins that are released with the postprandial reflex, reducing oxidative stress (which can lead to cell damage) and helping prevent atherosclerosis (buildup of cholesterol plaques in the arteries).

Increases insulin sensitivity: In a study of patients with obesity, OA was shown to up-regulate—increase the activity of—a gene that increases insulin sensitivity. OA also reduces insulin resistance in vascular smooth muscle cells, which make up the blood vessel walls.

Studies continue to reveal the ways in which OA exerts its multiple health-promoting effects. In 2018, the FDA determined that evidence supported a qualified health claim that the daily consumption of 20g daily of high-OA oil (EVOO or other high-oleic oil) may reduce the risk of coronary heart disease.

Stay tuned for part II, in which we’ll explore how the polyphenols in EVOO exert powerful protective effects against CVD.

References: 1. Lu Y, Zhao J, Xin Q, et al. Food Science and Human Wellness. 2024;13:529-540. 2. Pirahanchi Y, Sinawe H, Dimri M. Biochemistry, LDL Cholesterol (National Library of Medicine, 2023). 3. Zheng C, Khoo C, Furtado J, Ikekawi K, Sacks FM. Am J Clin Nutr. 2008;88(2):279-281. 4. US Food and Drug Administration. Constituent Update, November 19, 2018. https://www.fda.gov/food/cfsan-constituent-updates/fda-completes-review-qualified-health-claim-petition-oleic-acid-and-risk-coronary-heart-disease.