Can Dietary Supplements Slow Biological Ageing?

Advertising promises can sound tempting: more energy, fewer wrinkles and a “rejuvenated” body through specialist dietary supplements. At the same time, doctors warn against unrealistic expectations and potential risks. Between hope and hype lies a difficult question: can these products genuinely slow biological ageing, or are they an expensive illusion?

What biological age actually means

The age on your passport reveals only part of the picture. Experts distinguish between chronological age - the years since birth - and biological age. The latter reflects how much wear the body and its organs have actually undergone.

Biological ageing is assessed using factors including:

• Blood results, such as inflammatory markers or blood lipid levels
• Blood pressure and the elasticity of blood vessels
• Muscle strength and reaction speed
• Changes in genetic material, for example through so-called epigenetic clocks

A 65-year-old may be biologically comparable to a 55-year-old - or to a 75-year-old. Lifestyle and illness can shift this range far more substantially than a date of birth.

This is precisely where hopes surrounding dietary supplements begin: they are intended to slow processes that damage cells, fuel inflammation or weaken the body’s repair systems.

Which substances are marketed as “anti-ageing”

Attention centres mainly on substances thought to reduce oxidative stress and chronic inflammation, or to affect energy metabolism. Common candidates include:

• Antioxidants such as vitamin C, vitamin E, beta-carotene and selenium
• Omega-3 fatty acids from fish oil or algae oil
• Vitamin D and B vitamins, particularly B12 and folic acid
• Coenzyme Q10 and alpha-lipoic acid
• Polyphenols such as resveratrol, known from red wine, and green tea extracts
• NAD+ precursors such as nicotinamide riboside or NMN, which are intended to stimulate cellular metabolism

In laboratory experiments involving cell cultures and animals, some of these substances have produced striking results: longer lifespans in mice, reduced cellular damage and improved mitochondrial function - the cells’ “powerhouses”.

What human studies actually show so far

What matters, however, is what translates to people. On that point, the evidence is considerably more restrained.

Vitamins: useful, but not eternal youth in a bottle

With vitamins, the position is clear: deficiency is harmful. People who are seriously under-supplied can appear older and may be more vulnerable to infections and cardiovascular disease. Correcting such a deficiency improves health. This often leads to the mistaken assumption that “more is better”.

Yet large long-term studies indicate that, in healthy people without a confirmed deficiency, high-dose vitamin supplements neither reliably reduce mortality nor consistently extend life. In some cases, risk increased, including with very high doses of beta-carotene in heavy smokers.

Dietary supplements can fill specific gaps - they do not replace a balanced diet or turn a 70-year-old into a 40-year-old.

Omega-3 and similar supplements: modest effects, not miracles

Fish-oil omega-3 fatty acids slightly lower the risk of heart attacks in certain higher-risk groups. Some research suggests that they can improve inflammation markers. Whether they can measurably reverse biological age remains uncertain. The effects observed are generally modest.

The situation is similar for coenzyme Q10 and resveratrol: some smaller studies have found encouraging signals, for instance in relation to high blood pressure or insulin sensitivity. However, there is still no clear, broad body of evidence showing that they substantially slow biological ageing.

New “longevity” trends: NAD+, NMN and more

Over recent years, an entire market for so-called longevity supplements has emerged. These products focus on substances intended to boost cellular energy metabolism or influence particular ageing genes.

NAD+ precursors, especially nicotinamide riboside and NMN, are marketed heavily. In animal studies, they have sometimes extended lifespan and improved muscle strength and metabolism. Human evidence remains limited to a small number of mostly small studies, with partly positive but restricted effects on individual metabolic parameters.

Professional bodies urge caution: without robust long-term data, it is impossible to say reliably whether a slight rejuvenation of individual markers truly results in more healthy years of life, or merely makes laboratory results look better cosmetically.

Where dietary supplements can genuinely help

Despite the scepticism, there are clear circumstances in which supplements may be appropriate:

• With a confirmed vitamin D deficiency, particularly during winter or with limited sunlight exposure
• For people over 60 with low B12 levels, for example because of stomach problems or medication
• With a very restricted diet or certain dietary patterns
• For people who are medically unable to eat enough, such as after operations

In these situations, targeted supplementation often improves energy, muscle strength and overall wellbeing. It may indirectly have a positive effect on biological age because people become more active again, sleep better and maintain more social contact.

Limits and risks of the pill-based approach

The market for anti-ageing products is only lightly regulated. Many items are bought online, stated doses do not always match the contents, and contamination is possible. Interactions with medicines are also frequently underestimated.

Typical risks include:

• Excessive intake of fat-soluble vitamins A, D, E and K, which can build up in the body
• Disruption to blood clotting from high-dose omega-3 fatty acids when combined with blood-thinning medication
• Strain on the liver from taking numerous products together
• A false sense of security: “I take pills, so I do not need to change my lifestyle”

Anyone who genuinely wants to influence their biological age cannot avoid exercise, sleep and diet - supplements are at most a side dish, not the main course.

Lifestyle: the underestimated tool against rapid ageing

Alongside the debate about dietary supplements, studies repeatedly show that habits such as exercise, sleep quality and diet have the greatest influence on biological age.

Exercise - the most powerful “medicine”

Regular physical activity lowers inflammatory markers, supports glucose metabolism, keeps blood vessels flexible and protects brain structures. Just 150 minutes of moderate exercise each week - brisk walking, cycling or swimming - significantly reduces the risk of heart attack, stroke and dementia.

Studies often find that people over 55 who combine endurance exercise with light strength training have a markedly lower biological age than inactive people of the same age, even without taking a single dietary supplement.

Sleep and diet as a two-pronged strategy

Poor sleep measurably speeds up ageing processes. People who consistently sleep too little or restlessly are more likely to develop high blood pressure, excess weight and depression. On World Sleep Day, researchers repeatedly highlight how extensively the body repairs cells and reduces inflammation overnight.

Diet is equally important: a predominantly plant-based way of eating, rich in vegetables, wholefood carbohydrates, high-quality fats and low in highly processed products, is linked in many studies to slower epigenetic ageing. Those who obtain plenty of polyphenols, fibre and omega-3 fatty acids from food often need far fewer supplements in capsule form.

What a realistic anti-ageing plan may look like

Anyone wishing to improve their biological age should start with a basic check-up with their GP: blood tests, blood pressure, weight and a list of medicines. This provides the basis for deciding whether targeted supplements are appropriate.

A practical approach could include:

• Improving lifestyle foundations: more everyday movement, consistent sleeping hours and freshly prepared meals
• Having possible deficiencies checked, including vitamin D, B12, iron and omega-3 status
• Supplementing only after a deficiency has been confirmed, in consultation with a healthcare professional
• Avoiding high-dose experiments with trendy substances while sound long-term evidence is lacking

Dietary supplements can contribute to a slightly more favourable biological age, particularly when they address genuine gaps. The most powerful measures, however, remain cost-free routines: sufficient sleep, regular exercise and a diet that supplies the body with the building blocks it needs each day.

People over 55 who want to take an active role in their health usually benefit most from a combination of medical support, conscious lifestyle choices and, where necessary, carefully considered supplementation. The dream of eternal youth remains out of reach, but wise decisions can noticeably increase the number of healthy years.