Certain dietary patterns like intermittent fasting, beverages like coffee and green tea, and even playing brain games can all help slow the onset of the aging process (click to read more about those here). But what about the impact of supplements? Almost any vitamin, mineral, or bioactive compound (like phytonutrients) can be isolated into a supplemental form. And it’s enticing to believe that healthy choices can be simplified down to taking a pill, powder, or capsule, especially when many supplements tout anti-aging claims.
While InsideTracker takes a “food first” approach with diet and lifestyle recommendations, there are some instances and some biomarkers related to aging that can benefit from the extra boost supplements can provide. Supplements may play a role in lowering cholesterol, reducing blood pressure, regulating oxidative stress, and alleviating joint pain. But recommendations for supplementation are only viable when there’s enough scientific evidence to support them. And the science is still evolving.
Many InsideTracker customers have reported taking or are curious about the role quercetin, glutathione, N-acetylcysteine (NAC), rose hips, and glucosamine chondroitin supplements may play in longevity. Here's where the science stands for each of these supplements—and whether they've met InsideTracker's evidence threshold.
Quercetin supplements and heart health
Quercetin is the most abundant flavonoid (a type of antioxidant) in the diet—it’s found in fruits like apples, vegetables like onions and broccoli, as well as nuts, wine, and black tea . Antioxidant supplements like quercetin have primarily been studied because of their potential to mediate conditions commonly associated with aging, like high blood pressure and high cholesterol.
Quercetin has garnered the interest of consumers and researchers alike due to its presumed anti-inflammatory, immunoprotective, and anticarcinogenic properties. But despite querecetin’s potential role in health and its commercial popularity, InsideTracker does not currently recommend taking a quercetin supplement. Here’s why.
Evidence of quercetin and its effects on measures of cardiovascular health like cholesterol, blood pressure are either non-significant or have mixed results. Results from multiple studies shown that quercetin supplementation did not significantly impact cholesterol levels compared to the control (non-quercetin supplement) group.[2, 3]
Additionally, the antioxidant effect of quercetin should theoretically act as a vasodilator, expanding blood vessels to improve blood flow and reduce elevated blood pressure. But when it comes to the impact of quercetin on blood pressure levels, the evidence is mixed. Two meta-analyses found that quercetin supplementation of more than>500 mg per day (that’s a lot more quercetin that can be consumed naturally through foods)improved both systolic and diastolic blood pressure. [4, 5] (Read more about blood pressure here). However, other trials found that quercetin supplements had a null (non-significant) effect on blood pressure. [2,6] Due to this mixed evidence, InsideTracker can’t confidently recommend quercetin supplements as a way to improve cardiovascular health. But this recommendation could change as the science evolves
Although quercetin supplements may not yield significant results on blood biomarkers, food sources of quercetin can be cardioprotective. Quercetin containing foods elicit the antioxidant effect and contain other micronutrients that your body needs.
Key takeaway: Based on the current scientific literature, InsideTracker doesn’t recommend taking a quercetin supplement, but instead recommends eating foods high in this flavonoid including onions, apples, broccoli, and blueberries.
Glutathione supplements and longevity
Glutathione, often referred to as the “master antioxidant,” is responsible for both regulating oxidative stress and regenerating other antioxidants in the body (read more about antioxidants in this blog). This is a critical role in maintaining healthy cells throughout your body. Glutathione is endogenously produced from the amino acids, glycine, cysteine, and glutamic acid. This antioxidant can’t directly be obtained from the diet, but it is available as a supplement. Research shows that glutathione levels naturally decrease with age and that glutathione levels are lower in those with chronic diseases than those free of diseases. Unsurprisingly, scientists are interested in interventions that can target and increase glutathione levels, including whether glutathione supplements would be effective. But what does the research say about the presumed anti-aging supplement?
A study conducted in 2011 found that taking a twice-daily 500 mg glutathione supplement did not increase whole blood erythrocyte glutathione or plasma glutathione levels compared to a control group. A separate study from 2019 investigated the impact of 500 mg and 1000 mg of glutathione on glutathione levels in 12 participants.  And while both supplement dosages were associated with higher glutathione levels at the end of the study compared to the beginning, the study lacked a control group. So, we don’t know if supplementing with glutathione would consistently result in increased glutathione levels or whether such an increase would be clinically significant. Further research into the effects of glutathione supplements on measures of oxidative stress is warranted. Looking for scientifically backed ways to increase glutathione levels? Check out this blog.
Key takeaway: Despite the biochemical potential of glutathione supplements, research does not support the impact of this supplement on blood glutathione levels quite yet.
NAC supplements and glutathione levels for aging
Another supplement with rising popularity is NAC. When NAC is absorbed, it's converted into the essential amino acid cysteine, which is one of the three building blocks of glutathione. So researchers have postulated that supplementing with NAC may be a viable approach for increasing blood glutathione levels.
But the impact of NAC supplements on glutathione levels is mixed. Surprisingly, some studies have found that NAC supplements increased glutathione levels and other markers of antioxidant status more often than glutathione supplements themselves.  In contrast, other studies report no significant impact of NAC supplements on glutathione levels.  Due to these inconsistencies in the research, InsideTracker does not recommend taking an NAC supplement for aging.
Interestingly, NAC supplements may actually be detrimental to athletic performance. Some studies have investigated the impact of NAC supplements on exercise-induced oxidative stress and found little effect. But, these studies also found that decreasing oxidative stress post-exercise can negatively interfere with muscle growth and adaptation to exercise. Exercise-induced oxidative stress is a natural part of the training process and is necessary for the body to adequately respond to training demands.[10, 11] As a result, we do not recommend the use of NAC supplements for athletes.
While NAC isn't a component of foods, cysteine (what it's converted to in the body) is an essential amino acid. Foods that contain cysteine include eggs and chicken.
Key takeaway: NAC supplements don't consistently improve glutathione levels and may be detrimental to measures of athletic performance based on current research.
Rose hips supplements for joint and body composition
Rose hips are an extract from rose plant fruit Rosa Canina. Extracts are often ground up and packaged into supplements or added to teas. Rose hips have gained attention recently for their potential impact on alleviating arthritis pain, lowering cholesterol, and weight loss.
Rose hips supplements have primarily been studied in populations with existing joint pain from osteoarthritis. Rose hips were effective in reducing the perception of pain and stiffness in those with osteoarthritis. [12, 13] Use of rose hips as a preventative measure for joint pain, a characteristic of aging, is warranted.
A few studies have found that rose hips supplements may reduce LDL cholesterol in people with high levels. In addition, some research shows that taking a rose hips supplement for 12 weeks may benefit body composition measures like abdominal fat and body weight in those with an overweight BMI. Due to the limited number of studies on cholesterol and weight status, though, InsideTracker does not recommend taking a rose hips supplement at this time, but if you’re looking for cholesterol lowering recipes, check out this article.
Key takeaway: Rose hips supplements may be beneficial for joint pain related to osteoarthritis, LDL cholesterol, and body composition, but further research is needed to confidently recommend this supplement.
Glucosamine chondroitin supplements for strong bones
Another supplement with recent popularity for joint pain in aging adults is glucosamine chondroitin. Glucosamine and chondroitin are two components of cartilage that are often included in joint health supplements. As we age, the rate at which our bodies produce collagen decreases. Glucosamine chondroitin supplements presumably halt the natural decline in collagen production, resulting in improved joint health. Although glucosamine chondroitin supplements are anecdotally popular, the scientific evidence doesn’t support taking them.
Meta-analyses point to a connection between glucosamine chondroitin supplements and reduced joint pain in those with arthritis.But this result isn’t always consistent, and  evidence on the impact of this supplement in healthy populations is lacking.
Two studies conducted with male soccer players and cyclists found that glucosamine chondroitin supplements increased collagen production. [17, 18] However, these studies did not report an impact on performance-related outcomes. Because of the limited research of glucosamine chondroitin supplements in populations without joint pain, InsideTracker cannot confidently recommend it as a preventative measure. When in doubt, focus on foods that are rich in calcium and vitamin D.
Key takeaway: The current body of literature doesn’t support taking a glucosamine chondroitin supplement unless you’re currently experiencing joint pain.
A summary of the research on these popular supplements for aging:
- Based on the current literature, InsideTracker doesn’t recommend taking a quercetin supplement and instead recommends foods high in this flavonoid like onions, broccoli, apples, and blueberries.
- Despite the biochemical potential of glutathione supplements, research does not support the impact of this supplement on glutathione levels. Opt for foods like mushrooms instead.
- NAC supplements don't consistently improve glutathione levels and may be detrimental to measures of athletic performance.
- Rose hips supplements may be beneficial for joint pain related to osteoarthritis, LDL cholesterol, and body composition, but further research is needed before recommending a rose hips supplement.
- The current body of literature doesn’t support taking a glucosamine chondroitin supplement unless you’re currently experiencing joint pain.
Michelle Darian, MS, MPH, RDMichelle is a Nutrition Specialist at InsideTracker. As a Registered Dietitian, you’ll find Michelle analyzing the research behind recent nutrition trends, bringing actionable food and supplement recommendations to the platform. When she's not myth-busting, Michelle can be found exploring new restaurants and getting creative in her kitchen.