The concept of longevity has fascinated humans for centuries. From antiquity to modern times, people have sought out methods to counteract the effects of aging or even reverse them.
Vitamin C is an essential nutrient your body needs for many functions.
Some advocates believe that megadoses of vitamin C could increase lifespan and reduce disease risk.
However, the theory is not supported by scientific evidence.
Furthermore, high vitamin C doses can cause digestive disturbances, increased mineral excretion, and an increased risk of some health issues.
Whether through dietary and lifestyle changes, medicinal potions or elixirs, religious practices, technological advancements, or something else, people are constantly searching for a way to defy the natural boundaries of mortality.
Today, some longevity enthusiasts are turning to vitamin C megadosing as a potential strategy to delay the effects of time.
Vitamin C megadosing involves taking doses of vitamin C significantly higher than the recommended levels. Proponents of this approach argue that the antioxidant and anti-inflammatory effects of vitamin C can help protect against a wide range of diseases, including cancer and cardiovascular disease. However, taking large doses of vitamin C carries certain risks and can lead to digestive distress and more serious conditions.
So is vitamin C megadosing a worthwhile and safe strategy for achieving longevity? Can up your intake of vitamin C help you live longer? Continue reading to find out.
What is vitamin C?
Vitamin C, also known as ascorbic acid, is an essential nutrient that the body cannot synthesize. It's found naturally in many fruits and vegetables, including oranges, lemons, broccoli, and peppers. Because it's water-soluble, it's not stored in the body and must be consumed regularly to maintain adequate levels for health.
The body needs vitamin C for various critical functions, including:
Aiding immunity and protecting against infections.
Maintaining healthy skin, bones, and blood vessels.
Building collagen, a fibrous protein in connective tissues.
Assisting in wound healing.
Acting as an antioxidant to help protect against free radicals and toxin damage.
Enhancing immunity by strengthening the body's natural defenses.
Making hormones and chemical messengers used in the brain and nerves.
Without enough vitamin C, people can develop deficiency symptoms, including fatigue, joint pain, poor wound healing, and bleeding gums. Moreover, ongoing vitamin C deficiency can increase the risk of developing serious illnesses such as scurvy and certain types of cancer.
The recommended daily allowance (RDA) for adults is 90 milligrams (mg) per day for males and 75 mg for females. However, vitamin C megadosing involves taking much larger doses. In some cases, many thousands of times the RDA.
Alternative medicine advocates claim that vitamin C megadoses have preventive and curative effects on diseases and can promote longevity. But is there scientific evidence to support these claims?
The beginnings of vitamin C megadosing
A scientist called Linus Pauling (1901-1994) was one of the first to advocate for vitamin C megadosing. He claimed that taking massive doses of vitamin C could be used to combat various illnesses and even live longer.
Pauling’s publications are largely responsible for the widespread misbelief that vitamin C megadoses are effective against colds and other illnesses, even mental health disorders. He reportedly took at least 18,000 mg daily and increased the amount to 40,000 mg if he developed any cold symptoms. He also claimed that vitamin C had delayed the onset of his prostate cancer, despite dying of the disease.
In 1976, Pauling and another scientist, Dr. Ewan Cameron, reported that people with "terminal" cancer who were treated with 10,000 mg of vitamin C daily survived 3 to 4 times longer than untreated patients.
However, Dr. William DeWys, chief of clinical investigations at the National Cancer Institute, determined that the study was badly designed with unmatched patient groups. Furthermore, several clinical studies of patients with advanced cancer noted that those receiving 10,000mg of vitamin C didn't fare any better or live any longer than those who received a placebo.
The issues with megadosing theories
Pauling based his megadosing theories on the antioxidant properties of vitamin C. Antioxidants are valuable as they neutralize free radicals — unstable molecules that can cause cellular damage and, ultimately, many effects of aging.
In 1972, scientist Denham Harman claimed that reducing free radical levels may slow biological degradation and increase years of healthy life. But research has not shown that consuming high levels of antioxidants slows aging or increases longevity.
For example, in a study of 29,133 smokers, researchers gave participants different antioxidant supplements — vitamin E (alpha-tocopherol) and beta carotene — or placebo. In the beta-carotene group, the incidence of lung cancer increased by up to 16%.
In a study of postmenopausal women, after 10 years of taking the antioxidant folic acid daily, the risk of breast cancer increased by 20% compared to those who didn't take the supplement.
Of course, some studies demonstrate the benefits of taking antioxidants, but according to a review of 27 trials, the weight of evidence does not favor their value.
A further issue with the megadosing theory is that vitamin C is water-soluble. Therefore, your body can only absorb so much before the excess is excreted in the urine. Your body absorbs about 70 to 90% of vitamin C when taken orally at normal levels of 30–180 mg daily. If you increase the dose to 1,000 mg, only around 50% is absorbed. Even oral megadoses of 3,000 mg every 4 hours cannot raise blood concentration above 220 micromol/L. No matter how much vitamin C you consume, your body balances the levels in the bloodstream.
The risks of vitamin C megadosing
Consuming vitamin C at levels up to 2,000 mg likely won't cause any harm. However, there is a risk of digestive upset like diarrhea, nausea, and abdominal cramps. High vitamin C intake can also increase urinary mineral excretion, which can contribute to kidney stones.
There may also be more serious risks. In a study of postmenopausal women with diabetes, supplemental vitamin C intake of at least 300 mg daily was significantly associated with an increased risk of death from heart disease.
There is a lack of scientific evidence to support using megadoses of vitamin C to reduce disease risk or increase longevity. Providing you're consuming enough vitamin C in your diet, there's no need to take supplements, and they don't offer additional health benefits. Rather, they may even increase the risk of health issues.