Is the panacea of NAD supplementation actually effective in preventing premature aging?

Here we tell you about NMN, the supplement that could dethrone the popularity of NAD as the best antioxidant.

In recent years, NAD⁺ (Nicotinamide Adenine Dinucleotide) has gained great relevance in the field of regenerative medicine, longevity, and cellular health. But how effective is its supplementation really? And what role do its precursors play? Below, we will delve into these questions based on the latest scientific evidence.

Nicotinamide Adenine Dinucleotide (NAD⁺) is a coenzyme present in every cell of the human body, and it participates in numerous physiological reactions, with key relevance in the maintenance of mitochondrial function and a crucial role in cellular processes such as:

• Energy production (ATP)
• DNA repair
• Sirtuin activation (Proteins associated with longevity)
• Oxidative stress response
• Cellular metabolism

The problem is that, as the years go by, our NAD⁺ levels in the body naturally decline, as well as in conditions like chronic stress, poor diet, or metabolic diseases. Consequently, the decrease in NAD⁺ levels is associated with general aging, chronic disorders, such as cognitive decline, sarcopenia, and metabolic diseases (diabetes, cardiovascular diseases, etc.).

The most recent studies indicate that direct supplementation with Nicotinamide Adenine Dinucleotide is not bioavailable in the body, so consuming precursors is suggested so that the body can form NAD⁺ and thereby obtain its benefits.

The main research terms for NAD⁺ precursors were Nicotinamide Riboside (NR), Nicotinamide Mononucleotide (NMN), Nicotinic Acid (NA), and Nicotinamide (NAM).

• NA (nicotinic acid / niacin) → Converts to NAD⁺ through a process called Preiss-Handler, which is a biochemical pathway that transforms niacin into an active form of NAD⁺. It may have side effects (flushing or skin redness, discomfort, etc.).

• NAM (nicotinamide) → Part of the salvage pathway, a biochemical process in which the body reuses existing forms of NAD⁺ (like NAM) to regenerate new NAD⁺ molecules. This process is crucial when NAD⁺ levels are low. However, in high doses, nicotinamide could inhibit important enzymes such as sirtuins (proteins that regulate aging and cellular health) and PARPs (proteins that repair damaged DNA), thus affecting their function in the body.

• NR (nicotinamide riboside) → Part of the so-called 'salvage pathway'. In this process, NR is converted into a molecule called NMN (via the action of an enzyme called NRK), and then NMN is converted into NAD⁺. NR has been widely studied in humans and has been shown to have positive health effects.

• NMN (Nicotinamide Mononucleotide) → Is a nucleotide derived from vitamin B3. The biggest difference between NMN and NR is an additional phosphate group, so NMN has a more direct conversion. NMN also has a specific transporter that facilitates its direct entry into the cell. This means that consuming NMN can result in a faster or more efficient increase of NAD⁺ in certain tissues.

Two studies used NMN supplementation including an administration of 250 mg/day of nicotinamide mononucleotide for 48 and 56 days. In this study, it was observed that NMN intake in the afternoon effectively improved lower limb function and reduced drowsiness in older adults. The potential of NMN is related to the prevention of loss of physical performance, improvement of fatigue, increase in muscle insulin sensitivity and insulin signaling.

NAD⁺ is a large, polar molecule and is unstable, which hinders its intestinal absorption and its effective entry into cells. This limits its efficacy when administered orally.

According to Poljsak et al. (3), there are many alternative ways to increase NAD⁺ concentration that are related to lifestyle, such as reducing tobacco consumption, cigarettes, caloric intake and increasing regular exercise, regulation of circadian rhythms, sleep habits, caloric restriction, and improving dietary habits including vegetables, fruits, whole grains, and proteins. Regarding food and dietary habits, the daily requirements for NAD⁺ synthesis can be obtained with about 15 mg of vitamin B3, which can be found in meat and fish. However, the amount of specific foods consumed for the purpose of increasing NAD⁺ concentration would have to be enormous, hence the supplementation. Also, for example, a high-fat/sugar diet causes an energy overload, which culminates in a decrease in NAD⁺ levels. The literature states that the NAD⁺ level is not only controlled nutritionally, but also depends on sports activities and other lifestyle factors as mentioned above, so supplementation can act to stimulate NAD⁺ metabolism.

The clinical efficacy of NAD⁺ precursors has been evaluated in several studies. Below are the main findings summarized

Evidence in humans:

A systematic review of 10 clinical studies (489 participants) concluded that supplementing with its precursors can improve:

• Reduction in anxiety levels and heart rate
• Insulin sensitivity
• Chronic fatigue
• Sleep quality

Clinical trials with NMN (Nicotinamide Mononucleotide) in doses between 250 and 900 mg daily for 6 to 12 weeks have shown:

• Significant increases of NAD⁺ in blood
• Improvements in grip strength and walking speed in older adults
• Reduction of blood pressure and inflammatory markers in some cases

Although some clinical effects are not yet conclusive, the results are promising.

The most recent scientific evidence suggests that supplementation with NAD⁺ precursors, such as NMN and NR, may offer relevant benefits for metabolic health, physical function, and general well-being, especially in older adults or those with chronic conditions. Although direct NAD⁺ supplementation is limited by its low bioavailability, precursors have demonstrated greater efficacy in increasing NAD⁺ levels safely.

Clinical studies in humans have reported improvements in parameters such as insulin sensitivity, chronic fatigue, muscle function, and sleep quality, which suggests interesting therapeutic potential. However, more research is still needed to precisely determine optimal doses, treatment duration, and long-term effects.

In conjunction with healthy habits such as regular physical activity, a balanced diet, and good stress management, supplementation with NAD⁺ precursors represents an emerging and promising strategy to support cellular and mitochondrial health throughout aging.

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