Mediterranean diet can help lower heart failure risk, particularly in women

This review results was conducted by a team of experts from the University of Palermo, the Kore University of Enna, and the CNR Neuroscience Institute, all in Italy, in collaboration with colleagues from King’s College London, Anglia Ruskin University, and the University of Liverpool, in the United Kingdom.

The researchers originally searched through 682 prospective or retrospective cohort studies. They assessed data on adults aged 18 years and over without a history of heart failure at the baseline.

After eliminating publications due to duplication and other exclusion criteria, the team focused on six prospective studies that included 216,385 subjects living in Europe. Women made up 54.7% of the studied population.

The team transformed the varied scales of diet adherence used in the six studies into Mediterranean diet scores ranging from 0 to 9. They calculated the association between an increase in one point and heart failure risk.

After an average of 11 years of follow-up, 6,978 people developed heart failure. This amounted to 3% of the initial population in all the six studies analyzed.

Furthermore, the authors reported that an increase in one point in the Mediterranean diet score correlated with a “significantly lower risk of heart failure.”

Upon analyzing the association between adherence to the Mediterranean diet and heart failure incidence in men and women, the scientists said that “a positive association was observed in women.”

However, the association was not “statistically significant” in men.

Mediterranean diet refers to the traditional dietary eating patterns of people living along the Mediterranean coast. In its earliest days, the regimen was mostly vegetarian. Over 20 countries surround the Mediterranean Sea, so the exact foods used can differ in various places.

Wherever people follow the Mediterranean diet, they tend to incorporate high amounts of fresh foods, especially vegetables and fruits, as well as fish.

Medical News Today discussed the findings of the review with Ernst von Schwarz, MD, PhD, FESC, FACC, FSCAI, who is a clinical and academic professor of medicine at UCLA and UC Riverside.

Von Schwarz, who was not involved in this review, told us that “it’s [been] well known [for] many years that the heart-healthiest diet is the Mediterranean-type diet, especially because of the healthier fat intake.”

The “healthier fats” in question are monounsaturated fats, such as those found in olive oil, and polyunsaturated fats derived from fish and nuts.

The review authors also offered potential explanations for the Mediterranean diet’s protective effect against heart failure.

Firstly, they wrote, “the Mediterranean diet exhibits anti-inflammatory and antioxidant effects that could lower inflammation, oxidative stress, and endothelial dysfunction, which are the underlying complications leading to atherosclerosis, [cardiovascular diseases], and [heart failure].”

The diet may help lower lipids (fats) and protect against oxidative stress. It might also ”reduce levels of heart failure biomarkers.”

Michelle Routhenstein, MS, RD, CDCES, CDN, a preventive cardiology dietitian at EntirelyNourished, who was not involved in the review explained that:

“The Mediterranean diet may have a stronger impact on women because it addresses their specific nutritional needs, potentially helping to manage insulin resistance and inflammation, which can aid in slowing the progression of heart failure.”

Von Schwarz shared that heart failure symptoms in women are often “atypical or nonspecific.” He noted that there is often “a delay in the appropriate diagnostic steps, so conditions like a heart attack, unstable angina, or even heart failure are often diagnosed too late [in women].“

He added that heart failure in women tends to result more often because of uncontrolled hypertension, which leads to hypertensive heart disease. He also mentioned that diabetes is another major risk factor for heart failure.

According to Routhenstein, “women may be more susceptible to heart failure due to hormonal differences, different heart sizes and different patterns of heart remodeling.”

She also said that many risk factors may go unnoticed in women, which can increase heart failure risk as well. Pregnancy-related conditions, such as gestational hypertension or preeclampsia may also contribute to heart failure, noted Routhenstein.

Bradley Serwer, MD, an interventional cardiologist and chief medical officer at VitalSolution, an Ingenovis Health company, who was also not involved in the present review, further explained how hormonal risk factors can arise due to menopause.

“Native estrogen has a significant protective effect [and] postmenopausal women have a high risk [of heart problems] due to declining levels of estrogen,” he pointed out.

He also mentioned pregnancy and postpartum-related risk factors, noting that “peripartum cardiomyopathy can be seen in women who have recently been pregnant.”

The review authors concluded that their “meta-analysis confirms the important role of following the Mediterranean diet in preventing [cardiovascular disease].”

However, they also acknowledged that their work was subject to several limitations.

Their meta-analysis only reviewed six observational studies, few in number and susceptible to bias. Serwer noted that the review “does not show causality — only a correlation, and there is no proposed mechanism of action.”

Moreover, the six studies were all conducted in European countries. This makes the results difficult to generalize across all populations.

Furthermore, the Mediterranean diet in other European regions may be different than in the Mediterranean region, as lifestyles, climate, and food production likely vary.

Then, there is the issue that the studies analyzed covered the period between 1994 and 2013. Other recent research suggests that Mediterranean diet adherence is declining, which could have rendered different results.

Finally, several studies did not account for changes in Mediterranean diet adherence during follow-up, either.

MNT asked our experts when the best time is to get tested for heart failure.

Routhenstein emphasized that “heart failure has many stages and often there are no symptoms until the later stages.“

“I would recommend testing for heart failure in those with risk factors like a high lipoprotein(a), strong family history of heart disease or high blood pressure, diabetes, or heart disease,” she advised.

Serwer added that: “Heart failure is a clinical diagnosis which is […] based on symptoms and an examination. Anyone who has worsening shortness of breath, difficulty breathing while laying down, swelling of legs or significant fluid retention should be screened by trained medical professionals.“

He also recommended screening for people with a family history of cardiomyopathy, even if asymptomatic.

Finally, von Schwarz also advised cardiac examination in cases of “shortness of breath with little activity, especially if it’s a new onset. The most common symptom among more women than men is fatigue.”

He emphasized that age does not matter: Even people in their 20s may be vulnerable to heart failure.