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|All Health and Nutrition Bites|
Omega-3 supplements may not guard against heart attack
It's a tenet of today's nutrition advice, like eating whole grains or choosing lean meat: omega-3 fatty acids, found in fatty fish as well as plant sources like walnuts, flaxseeds, canola oil, and kidney beans, are good for your heart and have been shown to prevent heart disease.
Vitamin D supplements don't prevent cancer or heart disease
For years people have been taking Vitamin D supplements in conjunction with calcium supplements as a way to prevent bone loss. More recently some research has shown higher incidences of cancer and heart disease in people whose blood levels of Vitamin D were considered low.
B vitamin supplements linked to lung cancer
No, that's not clickbait: an analysis of data from a large-scale study of long-term dietary supplement use and cancer shows a strong link between long-term consumption of certain B vitamins and the risk of lung cancer.
The step-by-step guide to a Mediterranean Diet
Dr. Tim Harlan's best tips and recipes in a six-week plan for you to learn how to follow a Mediterranean-style diet while still eating foods you know and love. Just $15.00 +s/h!
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In the United States alone, the supplements industry brought in revenue of over 32 billion dollars in 2019 despite the overwhelming evidence that taking supplements - even of B vitamins, Vitamin D supplements (for cancer or heart disease), and Omega-3 supplements (for heart attack, heart disease, (or Alzheimer's) Early this year Washington Post published an article entitled, "Most dietary supplements don't do anything. Why do we spend $35 billion a year on them?"
Yet still we persist in believing that they are useful, at least for some populations. This month in JAMA was published the results of a randomized, controlled trial that assesses the effects of two supplements and one non-supplement intervention commonly prescribed to those over 65 (2020; 324(18):1855-1868).
1,900 men and women over the age of 70 completed the three-year study, which began recruitment in 2012. In the five years prior to recruitment, participants had to have no major health issues such as cancer or heart attack, had to be able to visit the study's lab without assistance, and scored at least 24 of 30 (essentially the minimum score for normal) on the Mini-Mental State Examination (a brief assessment of cognition).
The study authors were careful to see that at least 40% of participants had a history of falls in the year prior to the start of the study in an effort to include those adults who might be frailer than others.
Each participant was randomly assigned to one of 8 groups for the duration of the study:
1. Vitamin D and Omega-3 fatty acid supplements along with a strength training program;
2. Vitamin D and Omega-3 fatty acid supplements only;
3. Vitamin D supplement and a strength training program;
4. Vitamin D supplement alone;
5. Omega-3 fatty acid supplement along with a strength training program;
6. Omega-3 fatty acid supplement alone;
7. A strength training program alone; or
8. Placebo (no supplements or extra strength training program)
The Vitamin D and Omega-3 fatty acid supplements were standardized at 2000 IU/day and 1 g/day, respectively, and the strength training program included 3 days of supervised strength training per week as well as a joint flexibility program an additional 3 days per week.
The participants visited the lab at the start of the study and once yearly (at 12, 24, and 36 months) to undergo blood pressure tests as well as a cognitive assessment exam and a brief physical fitness test, both standardized exams. Phone calls from the lab or clinical visits every 3 months allowed the study staff to assess the frequency of infections or fractures (other than to the vertebrae). Reported infections and fractures were further assessed by medical records review by independent physicians.
The authors note that there is "evidence that older adults do not receive sufficient vitamin D, omega-3s, or exercise," so it's reasonable to think that receiving additional amounts of any of the three might improve health in one area or another.
Yet after three years the authors found "there was no statistically significant effect of any of the 3 treatments compared with their respective placebo/control" for blood pressures, infections, nonvertebral fractures, physical performance, or cognitive function.
In short, "These findings do not support the effectiveness of these 3 interventions for these clinical outcomes."
While we do know that for women of child-bearing age, taking folic acid supplements definitely helps prevent spina bifida in their children, there is still no good evidence that supplements are helpful for anyone who has not been diagnosed with a clinical deficiency. Unless your physician instructs you otherwise, don't waste your money on supplements.
First posted: November 25, 2020