Is sea moss (Irish moss) a worthwhile supplement?
As a food, sea moss has a reasonably good nutritional profile, but as a supplement there is no evidence that it provides a measurable health benefit. Also take into account variable quality and potential risks from iodine and heavy metals.
Sea moss (Chondrus crispus, a red alga) naturally contains proteins, fibre, minerals and fatty acids. As a food it therefore genuinely delivers nutrients, but whether a concentrated supplement has the same effect has not been demonstrated. Its composition varies considerably by species, season and growing location, which means you can never know exactly what is inside a jar.
In laboratory and animal research there are some interesting signals. Polysaccharides from seaweed showed immune-stimulating, anti-inflammatory and antiviral effects in laboratory experiments. An extract of Chondrus crispus protected nerve cells in a worm model against damage resembling Parkinson's disease. And substances such as carrageenan showed anti-cancer properties in experiments. However, all of these findings come from laboratory or animal research. There are no clinical studies in humans demonstrating that sea moss as a supplement provides a measurable health benefit.
There are also safety risks to take into account. Seaweed can accumulate heavy metals and naturally contains a high amount of iodine. Too much iodine can disrupt thyroid function. How large this risk is with a specific supplement depends on its origin and processing, and that information is absent from most packaging. The scientific literature explicitly identifies safety as an industry-wide issue.
In short: if you eat sea moss as part of a varied meal, you have a food with a reasonably good nutritional profile. As a supplement, in capsule form or as a gel, there is no evidence that it does anything you could not already achieve through ordinary food. The promising laboratory results are far from being translated into anything useful for humans.
All sources are reviews; no RCTs or controlled human studies on sea moss as a supplement are available. Laboratory and animal research exists, but does not justify any clinical claims.
Do antioxidant supplements make sense?
For healthy people, antioxidant supplements such as beta-carotene and vitamin E are not useful as protection against cancer or heart disease, and beta-carotene is frankly inadvisable for (ex-)smokers. The only well-supported exception is the AREDS formula for advanced macular degeneration: discuss this with your ophthalmologist.
How much iron do you need per day?
For healthy adults without a deficiency, 1 to 2 mg of iron per day through food is sufficient. When a deficiency or anaemia is confirmed, requirements are much higher; discuss that with your doctor.
Do you live longer by following the Mediterranean diet?
In large population studies, the Mediterranean diet is consistently associated with lower mortality and less cardiovascular disease; those who want to follow the diet as a whole have the strongest evidence on their side.
Is taking extra vitamin C worthwhile?
Extra vitamin C is of little use for most people. Intensive athletes and people following a carnivore diet do have good reason to supplement, and those who take it daily experience slightly milder cold symptoms on average.
How much magnesium do you need per day?
Research suggests that your body reaches balance at around 165 mg per day, but official recommendations are higher and there is considerable individual variation. In any case, make sure you get enough magnesium-rich foods, as a large part of the population falls short.
Are smoothies and fresh juice just as healthy as whole fruit?
Whole fruit beats fruit juice: more fibre, greater satiety and fewer free sugars. Smoothies fall somewhere in between, but are not equivalent to whole fruit either.