Which supplements are worthwhile after the age of forty?
A number of supplements have a reasonably solid evidence base after the age of forty: calcium plus vitamin D for bone protection, B vitamins and a daily multivitamin for cognitive maintenance, and adequate protein for muscle preservation. Collagen is worthwhile for the skin.
Bone protection is one of the clearest applications for supplements after the age of forty. Calcium combined with vitamin D reduces the risk of fractures by 15% overall and by 30% specifically for hip fractures, compared with a placebo. This effect was found in both community-dwelling and care-home adults of middle and older age, across eight randomised studies totalling approximately 31,000 participants.
For the brain, there are two points of interest. B vitamins (folic acid, B6 and B12) modestly slow cognitive decline in people without dementia, but the effect is small: a mean difference of 0.14 points on a cognitive test. Importantly, this effect was only visible with use lasting longer than twelve months. In people who already had dementia, it did not help. Higher folic acid intake was associated with a lower risk of dementia; the same was not true for B12 and B6. A daily multivitamin and mineral formula can improve episodic memory in people aged 60 and over and slightly slow cognitive ageing, equivalent to an average of roughly two fewer years of decline. This was consistently seen across three sub-studies involving more than 5,000 participants.
Maintaining muscle mass deserves extra attention after forty. Adequate protein intake is crucial for this: multiple randomised studies confirm that protein helps prevent muscle loss. Exactly how much, and which type works best, has not yet been definitively established. Vitamin D may also play a role in muscle mass and muscle function, but the studies are still too contradictory for firm statements about the ideal dose or duration. Omega-3 fatty acids, selenium and magnesium have also been studied in older adults; there are indications of an association with better muscle function, but the evidence is too thin for strong recommendations. Exercise and supplements together work better than either alone.
A smaller but notable result comes from a well-designed small study with 24 older participants: sixteen weeks of GlyNAC (glycine plus N-acetylcysteine, building blocks of the antioxidant glutathione) improved multiple ageing markers, including walking speed, muscle strength and inflammatory values. The supplement was safe, but the study is too small for broad recommendations; larger studies need to confirm this.
Collagen (hydrolysed, so that it is better absorbed) measurably improves skin hydration, elasticity and wrinkles after ninety days of use. This was found across nineteen randomised studies. One caveat: almost all participants were women, so it is less clear whether the effect is the same for men.
This answer is based on multiple reviews of randomised studies and a number of individual randomised trials. The strongest findings come from calcium plus vitamin D (fractures, approximately 31,000 participants), the COSMOS studies (multivitamins and cognition, more than 5,000 participants) and a review on B vitamins and cognition. The results for GlyNAC are promising but come from a single small study of 24 participants; the researchers themselves emphasise that larger confirmation is needed. For vitamin D in relation to muscle, and for omega-3/selenium/magnesium, the evidence is mixed and insufficient for firm conclusions.
Is colostrum (beestings) a worthwhile supplement?
For now, colostrum has the strongest indications as an aid against respiratory tract infections in athletes; for most other claims the evidence is too thin or too contradictory to recommend anything.
Do multivitamins help with healthy ageing?
Daily multivitamins appear to offer some protection for the memory of older adults, but for most other aspects of healthy ageing the effect is small or absent. If you have a confirmed deficiency in vitamins or minerals, supplementing is certainly worthwhile; do not regard it as a miracle remedy.
Is taking a stack of supplements at the same time smart or actually dangerous?
Whether a supplement stack is smart or dangerous depends on which substances you combine and whether you also use medications. Always tell your doctor or pharmacist what you are taking, and be especially cautious with St. John's wort and goldenseal.
Is spermidine from food just as good as a supplement?
There is no evidence that a spermidine supplement does the same thing as spermidine from food; supplements may be neutralised by the body and the effective dose in humans is unknown. If you want to increase your spermidine intake, opt for spermidine-rich foods.
Which supplements are best avoided in combination with blood thinners?
Several supplements can strengthen or weaken the effect of blood thinners; always mention them to your pharmacist or doctor before you start using them.
Which antioxidants have been proven to be beneficial?
Vitamin E has the best evidence base, particularly for asthma in children. For most other applications the indications are preliminary: use antioxidants as a complement to, not a replacement for, conventional treatment, and discuss them with your doctor if you wish to use them for a specific condition.