Cysteine is a semi-essential amino acid that plays a role in protein synthesis throughout the body. It is important for the healthy appearance of hair, nails and skin and is necessary for the proper functioning of the immune system.
L-Cysteine is considered to be semi-essential because our bodies can produce it, but in some cases we may need to supplement it through the diet. Cysteine is found in a number of common foods including soybeans, cod fish, beef, chicken, pork, lamb, oats, eggs and legumes.
As a supplement, Cysteine is usually taken in the form of N-acetylcysteine (NAC). NAC is derived from cysteine, and can be subsequently converted into one of the most important antioxidants: glutathione.
Health conscious individuals take N-acetylcysteine to increase levels of endogenous antioxidants and to improve liver function. It is used to detox the body, support the immune system and has been shown to increase endurance and reduce fatigue in athletes.
Skin
Hair
Anti- Aging- Promotes healthy skin, hair & nails
- Aids in the formation of collagen
- Supports protein structure for anti-aging
Why Use Cysteine Supplements?
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One of the main reasons to take Cysteine or N-acetyl Cysteine is to increase levels of glutathione in the body. This all-important antioxidant is made from NAC; in fact, NAC is the limiting factor in glutathione production.
Antioxidants like glutathione help the body to combat and prevent the damagers of oxidative agents like free radicals, toxins from the environment, and poisonous substances in mainstream foods.
Oxidizers cause damage to DNA and the membranes of cells. This damage is believed widely to contribute significantly to the development of various disease and to the processes of aging. It can also increase the risk of developing cancer.
Cysteine as N-acetylcysteine helps the body to break down mucus and is able to inhibit adverse side effects associated with reactions to toxins. It is also used by physicians worldwide to treat respiratory issues like bronchitis and chronic obstructive pulmonary disease (COPD).
The human body has a high tolerance to cysteine. Routine dietary supplementation is known to be safe and present very few side effects. Gastrointestinal upset is possible.
Top L-Cysteine Supplements
Best Food Sources for Cysteine
Cysteine can be manufactured inside the body from methionine, or gained from dietary sources. The following foods are known to have concentrated amounts of cysteine:
- Lean cuts of animal muscle (meat);
- Green leafy vegetables;
- Cottage and ricotta cheeses;
- Yogurt;
- Egg yolks;
- Red peppers;
- Wheat germ;
- Oat flakes;
- Granola
It is notable that cysteine in the form of NAC is not found in foodstuffs; it must be synthesized in the body or supplemented in pill form.
Effects of L-Cysteine
One of the effects of Cysteine is its ability to protect the liver from damage caused by toxins, such as certain drugs and alcohol.
NAC is used intravenously to treat overdoses of Tylenol (acetaminophen). It helps to limit damage sustained to the liver and kidneys.
Acetaminophen toxicity can be exasperated with alcohol consumption, or because of regular ingestion of other toxic substances, like illicit drugs or certain pharmaceuticals.
Many times, acetaminophen overdoses occur accidently, even at very low doses. Cysteine supplementation eases the symptoms and provides hepatoprotective (liver protective) and renoprotective (kidney protective) actions.
Chronic repetitive chest pain (angina) is treated with cysteine supplementation as well. NAC is often stacked with nitroglycerine in hospital settings. Nitroglycerine induces vasodilation, opening the blood vessels in the heart, lungs and the rest of the circulatory system. These two substances are often used together to alleviate chest pains, treat heart attack victims and to reduce the risk of cardiac death.
Combining cysteine and nitroglycerine often causes sharp, enduring headaches. It is not recommended to attempt to treat heart pains at home. Seek professional medical help.
An assessment of various clinical studies found that cysteine supplementation is effective at treating the symptoms associated with chronic bronchitis. One study showed significant reductions in flare-ups associated with bronchitis. In another study, symptom spikes were reduced by roughly 40% in patients with mild-to-severe COPD when cysteine administration was added to common treatment options.
In one 6-month human trial, people taking cysteine supplements were found to develop less instances of common influenza than those in a placebo group. 600 mg of NAC was administered twice daily to the treatment group.
- Promotes Healthy Skin, Hair and Nails
- Aids in the formation of collagen
- Supports protein structure and elasticity for anti-aging
When the lungs sustain injury, ARDS (acute respiratory distress syndrome) may develop. ARDS can be life threatening if not treated promptly and effectively. Introducing NAC through an IV may help to prevent and treat damages to the lungs due to ARDS onset.
Clinical data seems conflicted concerning cysteine capacities to combat ARDS. Research continues and home supplementation for ARDS symptoms is not recommended.
Cysteine is also implicated for further research concerning its effects on HIV and AIDS symptoms. Again, increasing glutathione synthesis is believed to be the primary source of action here. In one human trial, HIV patients were given NAC supplementation at 2400 mg daily.
After twelve weeks, treatment group participants had gained more weight than placebo group members. Other studies have failed to duplicate these results though. Further research is underway.
NAC supplementation may also be helpful for treating asthma symptoms and certain allergic reactions. It may also help to alleviate the dry mouth and eyes associated with Sjogren syndrome. Further, NAC may ameliorate the symptoms of cystic fibrosis and emphysema.
Cysteine supplementation is also thought to be helpful in the treatment of lung cancer, improving infertility, managing diabetes symptoms and preventing cancer of the colon. More research is warranted regarding all of these therapeutic possibilities.
How to Take Cysteine Supplements
Cysteine supplements are not recommended for pediatric use. Children and adolescents should use cysteine only under a doctor’s supervision. The best dosages for adults will be based on factors including the therapeutic targets, their ages, genders, health histories, food choices, water intake levels, physical activity levels, stress coping efficiency and more.
For general health enhancement via antioxidant effects, 500 mg once daily is a recommended starting point. Doses of 600 mg twice daily have been studied for COPD treatment. Also, 200 mg doses of cysteine have been tested for effectiveness against chronic bronchitis. Talk with your doctor about the optimal dose for you and whether it is better to use L-Cysteine or N-Acetyl Cysteine.
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- Zhang JQ1, Zhang JQ1, Liu H2, Zhao ZH1, Fang LZ1, Liu L1, Fu WP1, Shu JK1, Feng JG1, Dai LM1.Effect of N-acetylcysteine in COPD patients with different microsomal epoxide hydrolase genotypes. Int J Chron Obstruct Pulmon Dis. 2015 May 13;10:917-23. doi: 10.2147/COPD.S79710. eCollection 2015.
