Does sulforaphane from broccoli sprouts work against ageing?
Sulforaphane has impressive effects on ageing processes in laboratory and animal research, but whether this also holds true in humans has not yet been demonstrated. Eating broccoli sprouts is safe and potentially beneficial, but counting on measurable anti-ageing effects is premature.
Sulforaphane activates an antioxidant programme in cells through a regulatory switch known as Nrf2. That switch increases the production of protective compounds while simultaneously inhibiting a pro-inflammatory signalling pathway. The result: cells become more resilient against oxidative damage. This has been demonstrated consistently in laboratory and animal research, but large clinical studies in humans are still largely lacking.
In addition to its antioxidant effects, sulforaphane also stimulates the cell's 'waste-disposal' system. It activates the system that breaks down and removes damaged proteins. That may sound technical, but the significance is concrete: the accumulation of damaged cellular material is one of the hallmarks of ageing and neurodegeneration. In animal models, this activation leads to an average lifespan extension of as much as 30 to 60 percent, although that translation to humans has not yet been made.
Sulforaphane also influences which genes are switched on and off, by inhibiting enzymes that manage the 'settings' of DNA. In principle, this can regulate genes involved in ageing and cancer. The cell-level findings are clear, but what this means in practice for humans remains unknown.
The strongest evidence from human research concerns skin protection: a few small studies show that sulforaphane can reduce UV-related damage and redness. For major ageing outcomes such as Alzheimer's disease, Parkinson's disease or lifespan extension, there are only encouraging cell and animal studies, and no clinical evidence. Broccoli sprouts are therefore a rich source of a compound with interesting biological properties, but sulforaphane has not yet been proven as an anti-ageing agent in humans.
All claims are based on laboratory, cell and animal research, supplemented by limited human data (particularly for skin protection). Large randomised studies in humans are lacking for most anti-ageing outcomes.
Does the time of day you eat affect how quickly you age?
The time at which you eat does appear to matter, although the evidence in humans is still associative. A nightly fasting window of 10 to 12 hours and concentrating your meals during the day are the most concrete guidelines that current research offers.
Should I take vitamin B12 supplements as I get older?
Getting older increases the risk of a B12 deficiency, even if you eat healthily. A tablet of 1000 µg per day is safe and restores blood levels effectively; discuss this with your doctor. In addition to your B12 blood value, ask for your methylmalonic acid (MMA) level to be measured for a reliable picture.
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.
Does eating a high-fibre diet help against constipation as you get older?
Eating more fibre helps with constipation in older adults, but the overall dietary pattern matters at least as much as fibre grams alone. Always drink enough water when taking fibre supplements, and consult your doctor if you use medications or are unable to drink sufficient fluids.
Is a low-carbohydrate or ketogenic diet good for longevity?
A ketogenic diet can help with weight problems and metabolic disorders, but for people who simply want to live longer and healthier, no proven advantages over a varied diet have been demonstrated. Those who exercise intensively may even be at a disadvantage.
Does the timing of your meals affect how long you live?
The timing of your meals is associated with biological ageing and risk of death, but cause and effect have not been proven. Eating early, a nightly fasting window of at least 13 hours and a regular eating pattern appear to be the best choices based on what is currently known.