Meta-Analysis Finds Omega-3 Fatty Acids Do Not Reduce Cardiovascular Disease Risk
In a 2018 meta-analysis published in the journal JAMA Cardiology, researcher Theingi Aung and colleagues found that across 10 studies including a total of 77,197 participants, omega-3 fatty acid supplementation did not reduce risk of coronary heart disease in people at high risk. This newer finding conflicts with a 2017 advisory from the American Heart Association that suggested omega-3 fatty acid supplementation might prevent cardiovascular disease.
When it comes to mood disorders, it has been similarly difficult to pin down whether omega-3 fatty acids are helpful. Data on omega-3 fatty acid supplements for the prevention of depression have been ambiguous, with small numbers of studies and variations in study design that make it difficult to draw strong conclusions about whether these supplements can improve or prevent depression.
A 2016 systematic review by Paola Bozzatello and colleagues in the Journal of Clinical Psychiatry found only seven studies of omega-3 fatty acid supplementation in bipolar disorder. The studies had small sample sizes and widely varying dosage parameters, so the evidence that can be drawn from them is not strong, but the review did find a modest benefit on bipolar depression (but not mania) when omega-3 fatty acids were added to a treatment regimen, compared to treatment as usual.
The same review found that studies of omega-3 fatty acid supplementation in unipolar depression also varied widely, and thus it was difficult to draw inferences from them. Some meta-analyses found no benefit to omega-3 fatty acid supplementation, while others suggested that omega-3s could improve depression. The review found that the type of omega-3 fatty acids used might matter. Supplementation with EPA seemed to improve depression more than supplementation with DHA. The review also cited a 2014 comprehensive meta-analysis by Giuseppe Grosso and colleagues in the journal PLoS One that analyzed the findings from 19 studies in people with depression or depressive symptoms. Grosso and colleagues found that people with more severe depression seemed to benefit more from omega-3s.
Lifetime Heart Disease Risk Increases Dramatically When One or More Risk Factors Are Present in Middle Age
A meta-analysis of 18 studies that was published by Donald Lloyd-Jones in the New England Journal of Medicine in 2012 shows that increasing cardiovascular risk factors during middle age can dramatically increase a person’s risk of experiencing fatal cardiovascular disease, fatal coronary heart disease, nonfatal heart attack, or stroke later in life.
Data were analyzed from 257,384 patients, who included black and white men and women spanning a 50-year range of birth cohorts. The studies examined cardiovascular risk factors such as smoking, cholesterol levels, diabetes, and blood pressure at ages 45, 55, 65, and 75.
Having even one risk factor at age 55 dramatically increased the lifetime risk of cardiovascular disease compared to having no risk factors, and having more risk factors during middle age increased risk even further. Among people with no risk factors at age 55 (meaning cholesterol under 180mg/dL, blood pressure under 120 mm Hg systolic and 80 mm HG diastolic, nonsmoking and nondiabetic), men had 4.7% risk of death from cardiovascular disease by age 80 (compared to 29.6% for those with 2 or more risk factors). Women had a 6.4% risk of death from cardiovascular disease by age 80 (compared to 20.5% among those with 2 or more risk factors).
Lifetime risk of death from cardiovascular disease and coronary heart disease and risk of nonfatal heart attack were about twice as high in men, while risk of stroke was similar for men and women.
Across race, trends were similar, but this finding can be misleading. While African-Americans have more cardiovascular risk factors than whites, they are also more likely to die at younger ages from other causes before developing serious cardiovascular illnesses. Large studies with Latino and Asian American participants were begun too recently to provide robust data about long-term risk, but this research is expected to become available soon.
Editor’s Note: Watch your risk factors for heart disease, including high blood pressure, cholesterol, weight, and blood sugar. The more risk factors one has, the greater the increased risk of fatal cardiovascular illness.
Depression is also a risk factor for coronary artery disease, and should be treated just as aggressively and persistently as the other risk factors. Exercise is one element of a healthy lifestyle that can positively affect all of these risk factors. Implementing a healthy diet and exercise regimen by middle age will have long-term positive effects in reducing risks in older ages.
More Medical Comorbidities Among Bipolar Population
Goldstein and colleagues interpreted data from the National Epidemiological Survey in 2001-2002 that included 41,682 representative adults in the U.S. population sampled compared with 1,411 found in the community with a diagnosis of bipolar disorder.
Those with bipolar disorder had a 3.86 times higher odds of having coronary heart disease compared with those in the general population. They were also 2.15 times more likely to have hypertension. Most disturbingly, the mean age of those with coronary heart disease in the general population was 62.1 years of age, but in those with bipolar illness, it was 50.4 years of age. This indicates that the markedly increased risk and incidence of coronary artery disease occurred approximately 11 years earlier in those with bipolar illness compared with those without. Most interestingly, the number of prior depressive episodes correlated with the presence of either coronary heart disease or hypertension.
