Vitamin D and omega-3 supplements do not prevent cancer or heart disease, finds a new study, the latest long-standing discussion of their benefits.
More than 25,000 Americans from different ethnic groups who were over 50 years old have been convicted and had no history of cancer, heart attack, stroke or other forms of heart disease.
Participants are randomly assigned a daily dose of vitamin D, omega-3 or placebo. After more than five years, no significant cardiac disease or difference in cancer between those taking the additions and those taking placebo was not visible.
Major researcher Dr. Joann E. Manson, head of the Brigham Medical Center and Women's Hospital and Harvard Medical School professor, said the study is different because it is the largest random screening of this kind in the world.
Previous studies have been studying bone health or used in high-risk populations, she added, but her study had "primary goals that appear to have vitamin D and omega-3 to reduce the risk of cancer and cardiovascular disease" to typical people without the history of such conditions.
The results of VITamin D and Omega-3 TriaL – known as VITAL – were presented to the American Heart Association Scientific Sessions 2018 in Chicago and published in the New England Journal of Medicine.
The initial VITAL trial was held last year and involved more than 8,000 participants.
Research has shown that omega-3 fatty acids can prevent cancer and cardiovascular disease, according to the study, and vitamin D is suggested to reduce cancer risks, there are fewer cases of cancer in countries with high exposure to sunlight. Such observational studies are susceptible to confusing factors of lower cancer rates in places where there is greater exposure to sunlight, since people who spend more time out there are usually dealing with other healthy habits such as exercise.
"If you already have one or both of these supplements, there is no clear reason to stop. If you want to consider the beginning, it is a good idea to talk to your healthcare provider, but this is not to be done in an instant," Manson said.
Small vitamin D protection
The study was a major clinical randomized study, said Brian Power, an honorary senior dietician at University College London Hospital and a nutrition lecturer who did not participate in the study. He described it in the e-mail as "the gold standard for assessing the effectiveness of such interventions, bias and confusion reduced."
Looking at a moderate to high dose of 2,000 IU of vitamin D, 1,617 people developed cancer; of which 793 were regular vitamin D and 824 in a placebo group.
Also, 905 participants developed major cardiovascular events such as stroke, stroke or death due to cardiovascular disease. Of them, vitamin D supplements were taken 396 daily; the placebo group had 409 major cardiovascular events.
Researchers have concluded that the difference is too small and says there is no link between vitamin D and reduced risk of major cardiovascular events or invasive cancers.
Anastasia Z. Kalea, a senior lecturer at the Center for Cardiovascular Genetics at the University of London, who was not part of the study, said the results were "very important but not surprising." Both conclusions are doubtful, and the trial supports them, she added,
The study shows that vitamin D supplements are not possible to prevent cancer, and the difference between placebo and vitamin D is minimal, Kalea said.
However, during the study, cancer mortality was significantly reduced by 25% for those taking vitamin D supplements. This finding requires further research, but Manson thinks this can explain vitamin D affecting tumor biology, making it less likely that the tumor will grow and spread.
Recent research has also rejected the theory that vitamin D improves bone health and prevents the fracture, but some experts disagree, citing small time periods and sample sizes as well as inadequate doses.
Some benefit from omega-3
In the omega-3 analysis, invasive crabs were detected in 820 participants taking daily 1 g of omega-3 and 797 who received placebo.
Also, 386 people taking 1 gram of omega-3 experienced cardiovascular events during the study as well as 419 people taking placebo.
However, for heart attacks, findings showed a total 28% reduction in those who are taking omega-3 supplements. For African Americans, the study found 77% reduction in heart attacks associated with daily omega-3 supplements.
In people who did not eat the recommended one or two portions of fish a week, supplements were associated with 40% reduction in heart attacks. But for those who followed the recommendation, there was no such association.
Manson recommends that you try to get omega-3 from a healthy diet that includes fish. But people who do not eat or do not like fish should talk to the doctor about the option of omega-3 supplements.
"It could be accidentally found," said Manson, and should be repeated. But if this is confirmed, it could point to a "promising approach to reduce health differences. "
Nathan Davies, head of the Clinical Nutrition and Public Health Program at the University of London, said that these findings are not "radical in any way, but there may be some benefits but not so clear."
The results show that omega-3 oils are not harmful, Davies adds, who did not participate in the study.
However, he noted that the study could benefit from longer duration. "You always want a longer life, especially if you look at cancer."
It also does not analyze whether there is a dose-dependency effect and a higher dose can lead to better results, Davies said.
"Diet is more important than supplementation. If you have a good diet, you will not need any supplements," he said, adding that this is not always practical, as factors such as income and availability may also affect nutrition.
Victoria Taylor, a senior physician at the UK Heart Foundation, wrote in an e-mail: "We do not recommend taking vitamins and mineral supplements to prevent heart and circulatory system diseases, and the results of this research support our advice.
"If you eat a healthy, balanced diet of Mediterranean style, you should be able to get all the nutrients you need to protect you from heart disease and circulation," she added.