The Truth Behind Turmeric, Fish Oil, and Probiotic Supplements

It’s estimated that over half of all Americans are taking some kind of dietary supplement. Americans are investing billions of dollars each year into the supplement industry in the hopes of improving their overall health. It seems like there’s a hot new supplement on store shelves every month. However, consumers should always keep two questions in mind before jumping on the latest supplement craze: does it work, and is it safe?

When it comes to effectiveness, many of today’s supplements promise consumers incredible results with little effort. While there is some promising research on the mechanisms of these supplements, the fact is that most aren’t regulated by the FDA, which is reason for concern.

In terms of safety, a study published last year in JAMA Network Open revealed that hundreds of supplements on the market included unlabeled ingredients, while others included ingredients that aren’t approved by the FDA. In response to this growing problem, the FDA unveiled its Dietary Supplement Ingredient Advisory list in April to protect consumers from potentially unsafe ingredients in dietary supplements. It’s also important to note that the rules for manufacturing and dispensing dietary supplements are far less stringent that those for over-the-counter or prescription medications.

With the supplement market crowded with misinformation and flooded with new pills and powders on a daily basis, I wanted to provide a medical perspective on some of the supplements patients ask me about most frequently.

The truth behind probiotic supplements

A blister pack of probiotic supplements featuring each supplement's name

Probiotics are bacteria that live in the body and help it work well. They’re also known as “good bacteria.” Examples include strains of lactic acid bacilli (like lactobacillus and Bifidobacterium), a nonpathogenic strain of E. coli (E. Coli Nissle 1917), and Saccharomyces boulardii (a nonpathogenic strain of yeast). There are also strains under development that have been genetically engineered to secrete immunomodulators, which have the potential to favorably influence the immune system.

Researchers continue to study whether or not probiotic supplements can help fight or prevent a number of illnesses, including diarrhea, constipation, irritable bowel syndrome, ulcerative colitis, Crohn’s disease, allergies, and vaginal infections. This research may yield promising results down the line, but while there’s solid proof probiotics help the body, there isn’t solid proof that taking probiotic pills improves one’s health.

Because there’s no proven benefit to taking probiotic pills, you shouldn’t take them unless your health care provider recommends them. Like other supplements, probiotic pills aren’t regulated by the FDA. There’s a small chance that they could do you harm (especially if you have a weakened immune system), as they could lead to infection.

The truth behind turmeric

Turmeric powder on a wooden spoon pictured next to several turmeric supplement pills

Turmeric is a spice that comes from the turmeric plant. It’s commonly used in India and other parts of Asia both as a spice for cooking and as a medicinal herb. The studies available use turmeric extracts that contain mostly curcumin, with dosages usually exceeding 1g per day, which is more than one would likely ingest solely from cooking with turmeric.

Turmeric has become increasingly popular due to its anti-inflammatory properties. More and more research is pointing to inflammation being a key contributor to many chronic diseases, including heart disease, cancer, elevated cholesterol, and Alzheimer’s disease.

Based on early cell culture and animal research, some clinical trials indicate curcumin may have potential as a therapeutic agent in treating conditions like inflammatory bowel disease, itching, pancreatitis, arthritis, and chronic anterior uveitis, as well as certain types of cancer.

Some research shows turmeric extract may decrease total cholesterol, LDL (also known as “bad” cholesterol), and triglycerides. Other research shows taking turmeric extract alone or in combination with other herbal ingredients can reduce pain and improve function in patients with osteoarthritis about as well as ibuprofen. However, these studies are very small and limited, so the quality of the evidence is limited.

Currently, there’s insufficient evidence to support the use of turmeric for other conditions, like diabetes and inflammatory bowel disease. Early research shows no benefits from six months of turmeric supplementation in patients with Alzheimer’s.

Are there drawbacks to turmeric supplements?

Turmeric may lower testosterone and decrease sperm count in men, which may reduce fertility. High doses of turmeric may affect the absorption of iron, meaning patients with iron deficiency should use caution.

Turmeric may slow blood clotting, so patients scheduled for surgery should stop taking turmeric two weeks before their procedure. Turmeric also may increase the effects of certain medications, meaning you should check with your pharmacist or primary care provider if you have other prescriptions. Turmeric may also decrease blood sugar in patients on certain diabetic medications.

The truth behind fish oil supplements

A woman holding several fish oil supplement pills in the palm of her outstretched hand

Fish oils can be obtained naturally from eating fish, or can be ingested through the use of fish oil supplements. Fish that are especially rich in beneficial oils known as omega-3 fatty acids include mackerel, herring, tuna, and salmon. Two of the most important omega-3 fatty acids in fish oils are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Fish oil preparations are available by prescription (regulated by the FDA as a medication) or as nutritional supplements (regulated by the FDA as a supplement or food substance). They have been shown to lower triglyceride levels, which may help lower the risk of heart disease.

Fish oils are also used for other heart conditions and for multiple inflammatory and autoimmune disorders. Fish oils may help prevent a second heart attack if taken within hours of the first and taken for a year following the event. Fish oils may help lower blood pressure in patients with hypertension. They also might help reduce stiffness in some patients with rheumatoid arthritis and decrease headaches in some migraine sufferers.

Fish oils do not seem to help decrease atherosclerosis (hardening of the arteries), improve diabetes control, or help manage gum disease, lupus, hay fever, or asthma.

Are there drawbacks to fish oil supplements?

Fish oil supplements are likely safe for most people in lower doses (3g or less per day). High doses may reduce immune function, making them dangerous for the elderly, transplant patients, or patients with HIV.

People who are allergic to fish or seafood may also be allergic to fish oil supplements. There is also some research suggesting that fish oil may increase the risk of irregular beats in patients with a defibrillator. Also, it’s not advisable to consume large amounts of fish in order to boost dietary fish oil intake due to possible contamination with mercury and other industrial and environmental chemicals. 

Like turmeric, fish oil may slow blood clotting, so patients with a scheduled surgery should stop regular consumption two weeks before scheduled surgery.

The bottom line on supplements

For most people, regular exercise and a healthy diet that is plant-based (the goal is 3-5 servings of a variety of fresh fruits and vegetables per day) combine to provide more health benefits than any supplements.

There are exceptions, of course. Supplements may be beneficial for people who are vegan or are following a more restrictive diet. Women of child-bearing age should take a folic acid supplement, while post-menopausal women should take a calcium supplement if they’re not getting enough in their diet.

Because there are a few other health conditions that may require supplementation, the best way to determine if you should be adding any supplements to your diet is to have a discussion with your healthcare provider.

If you want to do a little reading before you talk to your care team, I recommend checking out these websites, which present information on supplements and the possible risks and benefits in a clear way:  

It’s a good idea to have a conversation with your provider when you’re considering making any changes to your lifestyle. It’s especially important in the case of supplements, as you want to be sure you aren’t ingesting anything harmful and won’t be interfering with any medications you take.

Brandy Petersen, CNP sees patients at South Shore Medical Center in Braintree and Norwell. Learn more about Primary Care at South Shore Health.