In the news: New Findings on Vitamin D & Fish Oil in Chronic Conditions

Vitamin D May Help COPD Patients

The last issue of Staying Healthy discussed research that reported benefits of maintaining normal blood levels of vitamin D for people with asthma. According to a new study funded by the UK’s National Institute for Health Research, avoiding low blood levels of this vitamin is also important for those with chronic obstructive pulmonary disease (COPD).

COPD is often a mix of chronic bronchitis and emphysema, which makes breathing difficult. Most people who have COPD are current or former smokers. Long-term exposure to other lung irritants – such as air pollution, chemical fumes, or dust – is also thought to contribute to COPD.

In this multi-center study (1), half of the participating 240 COPD patients were randomly assigned to take vitamin D supplements and half received a placebo for 1 year. The risk, severity and duration of disease flare-ups were compared between the two groups.

COPD patients with low blood levels of vitamin D (baseline concentrations below 50 nmol/L) benefited significantly from the supplements, with a more than 40% reduction in moderate to severe flare-ups. Participants who already had higher vitamin D status at the trial’s start did not experience that dramatic improvement, though all patients receiving vitamin D had a modest reduction in the severity and duration of flare-ups compared to placebo-takers.

Fish Omega-3s May Lower Risk of Deep Vein Clots

Venous thromboembolism (VTE) is a condition that includes both deep vein thrombosis (DVT) and pulmonary embolism. DVT is the formation of a blood clot in a deep vein – usually in the leg or pelvic veins. The most serious complication of a DVT is when the clot dislodges and travels to the lungs, becoming a pulmonary embolism. According to Johns Hopkins Medicine, deaths from VTE in the US and UK exceed those from AIDS, breast cancer, prostate cancer and traffic accidents combined.

Results of a large population-health study conducted in Norway link regular intake of omega 3s from fish and fish oil with a reduced risk of VTE (2). The researchers collected and analyzed data from more than 23,600 people over an average 16-year period. They found that eating 3 or more servings of fish weekly was associated with a 22% lower risk of VTE compared to consuming 1-2 servings per week.

Adding fish oil to this dietary regimen increased the apparent benefits, with a 48% risk reduction compared to those eating fish fewer than twice weekly and not taking omega 3 supplements. This promising association now needs to be tested in clinical trials.

Omega-3s Impact High Blood Pressure

Hypertension is common in the US, and millions more have high blood pressure and don’t know it or have pre-hypertension – slightly elevated levels that could lead to hypertension. Results of a meta-analysis (3), which included 70 controlled trials, suggest that consuming omega 3-rich foods or supplements could reduce high blood pressure.

The strongest effects of the omega fatty acids EPA and DHA were seen among people with elevated blood pressure who were not being treated for the condition. The average reductions in systolic pressures (the top number in blood pressure values) and diastolic pressures (the bottom number) were 4.51 mm Hg and 3.05 mm Hg, respectively.

For perspective, studies in people with untreated hypertension show that reducing salt intake decreases systolic pressure by 2-8 mm Hg, alcohol by 2-4 mm Hg, and that increasing physical activity reduces systolic values by 4-9 mm Hg. Since blood pressure tends to rise with age, a healthy lifestyle may help some people delay or prevent this increase.

References

1. Martineau AR, et al. Vitamin D3 supplementation in patients with chronic obstructive pulmonary disease (ViDiCO): a multicentre, double-blind, randomised controlled trial. Lancet Respir Med, Published online Dec 1, 2014.
2. Hansen-Krone I, et al. High fish plus fish oil intake is associated with slightly reduced risk of venous thromboembolism: the Tromsø Study. J Nutr 144:861-67, 2014.
3. Miller P, et al. Long-chain omega-3 fatty acids EPA and DHA and blood pressure: a meta-analysis of randomized controlled trials. Am J Hypertens 27:885-96, 2014.