Cardiovascular diseases in women: risk increases after 40 due to omega-3 deficiency

Over 70% of women aged 40 to 59 show a high likelihood of suffering from cardiovascular diseases due to insufficient concentrations of EPA and DHA in the blood. According to a study conducted on the German female population, almost all middle-aged women have a low Omega-3 Index, meaning a low percentage of EPA and DHA in red blood cell membranes, a dangerous condition for heart health and beyond.

The research, conducted by scientists at Leibniz University Hannover (Germany), was published recently in the journal Prostaglandins, Leukotrienes and Essential Fatty Acids.

Omega-3s protect heart health

The positive effects of proper omega-3 consumption are numerous, well documented, and approved by EFSA (European Food Safety Authority), especially concerning brain and cardiovascular health. The association between EPA and DHA intake through diet and cardiovascular prevention was first observed in the mid-20th century in a study involving the Inuit population in Greenland, showing reduced cardiovascular disease incidence linked to a fish-rich omega-3 diet. The relationship between a fish-rich diet and cardiovascular protection has since been confirmed by many epidemiological studies. The mechanisms by which omega-3s exert cardiovascular protective effects include:

• increasing cell membrane fluidity
• improving endothelial function
• modulating platelet aggregation
• having antiarrhythmic action
• reducing blood triglycerides

For this reason, measuring an individual's omega-3 levels, particularly the fatty acid composition of red blood cells, is important to define cardiovascular risk. Blood concentrations of DHA and EPA can be measured through the Omega-3 Index, a new method for assessing cardiac risk. The Omega-3 Index represents the sum of omega-3s in red blood cell membranes, expressed as the percentage of EPA and DHA out of the total fatty acids present in the membrane. A low index value is associated with a higher probability of sudden cardiac death, i.e., unexpected cardiac arrest even in individuals with no previous cardiac dysfunction. Conversely, a high Omega-3 Index is linked to a lower risk of sudden cardiac death. Based on numerous epidemiological studies on the link between sudden cardiac death risk and omega-3 levels in red blood cells, scientists concluded that:

• Omega-3 Index < 4%: indicates a high probability of sudden cardiac death
• Omega-3 Index between 4 and 8%: moderate risk
• Omega-3 Index > 8%: indicates a low risk situation

Several studies have shown that omega-3 levels in women from Western countries are low. The aim of this new study was to assess omega-3 status in German women and identify influencing variables.

Omega-3 Index too low for almost all women in the study

The research on the German female population revealed that the vast majority of middle-aged women do not consume enough omega-3 through diet, with 97.3% of all women studied having an Omega-3 Index below 8%, indicating a dangerous situation for heart health. Specifically, 62.8% of women had an Omega-3 Index between 4 and 6%, while a small percentage (9%) had an index below 4%; a risky condition for heart health, but also associated with increased chances of cognitive decline and depressive symptoms. As noted by Professor Sandra Geller, who led the study, cardiovascular diseases are the leading cause of death in Europe and have a higher incidence in women than men, increasing with age. Cardiovascular events occur in 10% of women aged 20 to 39, rising to 35.5% among women aged 40 to 59.

Study details

The German research team analyzed data from 446 women aged 40 to 60 who had previously participated in a much larger national study. Omega-3 levels in red blood cell membranes were measured for each participant, expressed as the percentage of EPA and DHA relative to total fatty acids present. The average Omega-3 Index score was 5.49. Reference values for the index in this study were classified as: very low (below 4%), low (4%-6%), moderate (6%-8%), or high (above 8%). Data showed that the Omega-3 Index seemed influenced by age and smoking status, with slightly higher values in women over 50 and non-smokers. Those taking hormonal contraceptives showed lower EPA levels and a lower ratio of EPA to alpha-linolenic acid (a precursor of EPA and DHA) compared to women not using hormonal contraception.

Women need to increase omega-3 levels

The study showed that over 97% of middle-aged women have an Omega-3 Index below 8%, the value considered protective for the heart. This suggests the need to increase omega-3 intake to reduce the risk of cardiovascular disease, depression, and cognitive decline. The authors also noted that current German recommendations for omega-3 consumption focus only on alpha-linolenic acid, despite the known low conversion rate of this fatty acid to EPA and especially DHA. Reference doses for EPA and DHA from various scientific organizations and competent authorities range from 250 to 500 milligrams per day for healthy adults.

Source: Sandra Gellert, et al. “Low long chain omega-3 fatty acid status in middle-aged women” Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA)