The first clinical application of alpha lipoic acid was used by German doctors to treat acute poisoning caused by deadly mushrooms (death cap), and by the 1980s, lipoic acid began to be found to be a powerful antioxidant, both fat-soluble and water-soluble, with the effect of resisting a variety of chronic diseases, so it gradually attracted attention
Dr. Lester Packer, an American antioxidant pioneer, mentioned in his book “The Antioxidant Miracle” that alpha lipoic acid is an ideal super antioxidant and an important role in the body’s antioxidant network
In empirical medicine, what are the benefits of taking alpha lipoic acid? Are there any side effects of alpha lipoic acid? See text analysis for details.
What is Alpha Alpha Acid?
The origin of alpha-lipoic acid comes from the discovery by scientists Snell and others in 1937 that certain bacteria require a compound in potato extract to grow, and a few years later, the growth factor was isolated, that is, alpha lipoic acid.
In recent years, it has been found that lipoic acid is a cofactor involved in energy production and catabolism in the mitochondrial glands, and is closely related to glycolysis and citric acid cycle.
In addition to this, alpha lipoic acid is a powerful antioxidant whose potential functions include the following:
(1) Inhibit reactive oxygen species
(2) Regeneration of exogenous and endogenous antioxidants such as vitamin C, E, and glutathione
(3) Chelation of metal ions
(4) Oxidized protein repair
(5) Gene transcription regulation
(6) Inhibition of nuclear factor kapp B
What are the proven benefits of alpha lipoic acid?
1. Alpha lipoic acid is beneficial to blood lipid regulation
Hyperlipidemia is defined as an increase in the concentration of total cholesterol on an empty stomach, which may also be accompanied by an increase in triglyceride concentration.
Dyslipidemia is associated with a range of health problems such as obesity, insulin resistance, and cardiovascular disease. Associated risk factors include: smoking, obesity, sedentary lifestyle, excessive intake of saturated fats, and intake of foods high in trans fats.
A systematic literature review and meta-analysis (11 controlled clinical trials with 452 adult participants) noted that α-lipoic acid supplementation significantly reduced serum triacylglycerol, total cholesterol, and low-density lipoprotein levels. However, there was no significant effect on serum high-density lipoprotein. Note 1
In addition, subgroup analysis found that the effect of lipoic acid on regulating blood lipids was most significant in subjects with a body mass index of > 30 kg/m2 and a daily dose of >600 mg.
*Conclusion: Alpha lipoic acid supplementation may bring positive help to blood lipid regulation, but due to the heterogeneity of the samples included, more studies are needed to further verify
2. Alpha lipoic acid is beneficial for blood sugar control
Diabetes mellitus is a metabolic disorder characterized by high blood sugar. According to the ability of pancreatic cells to secrete insulin, it is mainly divided into insulin-dependent type 1 diabetes mellitus (insufficient insulin secretion) and non-insulin-dependent type 2 diabetes (insufficient insulin sensitivity and glucose uptake in peripheral tissues).
In the same patient, impaired insulin secretion and defective insulin action often coexist, and it is often unclear which are the main causes of hyperglycemia. Obvious symptoms of hyperglycemia include polyuria, polydipsia, weight loss, sometimes accompanied by polyphagia and blurred vision.
A systematic literature review and meta-analysis (28 placebo-controlled trials with 1016 participants) noted that alpha lipoic acid supplementation significantly reduced serum insulin and insulin resistance levels (HOMA-IR), but had no significant effect on glucose or glycosylated hemoglobin (HbA1C). Note 1
In addition, the timing of lipoic acid supplementation was dose-dependent with insulin changes.
The mechanism behind it may be related to the stimulation of AMPK activity of skeletal muscle and adipose tissue, phosphoinositol-3-kinase and protein kinase B, thereby improving tyrosine phosphorylation of insulin receptors.
*Conclusion: Thioxine supplementation may have a positive effect on glycaemic control, but more studies are needed to support this due to heterogeneity between studies
3. Alpha lipoic acid regulates blood pressure
Hypertension is an abnormal increase in arterial blood pressure, defined as systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg. The gray area with a systolic blood pressure between 120 and 139 mmHg and a diastolic blood pressure of 80 to 89 mmHg is defined as prehypertension.
In addition to elevated blood pressure positively correlated with the risk of stroke and coronary heart disease, complications include heart failure, peripheral vascular disease, renal impairment, retinal hemorrhage, and visual impairment.
A meta-analysis (7 randomized controlled trials, 478 participants) noted that lipoic acid supplementation (daily doses from 300 to 1800 mg for 8 to 20 weeks) had a systolic and diastolic blood pressure lowering effect, particularly in subjects with slightly higher-than-normal blood pressure (<130/80 mmHg). Note 1
*Conclusion: Oral lipoic acid has a hypotensive-lowering effect in subjects with slightly higher than normal blood pressure, but more studies are needed to support this due to the heterogeneity of the included studies and the small sample size
4. Alpha lipoic acid improves diabetic peripheral neuropathy
Diabetic peripheral neuropathy, the most common microvascular complication in people with diabetes, increases the risk of foot infections, ulcers, and non-traumatic amputations, ultimately leading to long-term disability.
Characterized by tingling, burning, pain, cramping, paresthesias, or numbness, usually worse at night, causes sleep disturbances that seriously affect the patient’s quality of life and ability to perform daily activities.
Diabetic peripheral neuropathy is generally associated with metabolic disorders, oxidative stress, vascular damage, nerve ischemic damage, and autoimmune disorders caused by long-term hyperglycemia.
A systematic literature review and meta-analysis (20 randomized controlled trials involving 1894 patients with diabetic peripheral neuropathy) noted that The efficacy of alpha lipoic acid and drugs (epalrestat) is significantly better than that of use alone, and can significantly improve median motor nerve conduction velocity (MNCV), median sensory nerve conduction velocity (SNCV), fibular MNCV and fibular SNCV. Note 2
*Conclusion: Alpha lipoic acid + epalretat combination therapy can significantly improve clinical efficacy and accelerate nerve conduction compared with lipoic acid or epalretat monotherapy, but more large-scale randomized controlled trials are needed to support these findings
5. Alpha lipoic acid improves inflammatory markers
Inflammation is the physiological protective response of an organism (whether physical, chemical, or biological) to harmful stimuli, which can eliminate or neutralize foreign organisms or substances and is used to re-establish homeostasis.
Generally, the inflammatory reaction begins within a few minutes and if all goes well, it disappears within a few hours. Instead, chronic inflammation can last for weeks, months, or even years.
Increased chronic inflammation is associated with metabolic diseases, including type 2 diabetes, arteriosclerosis, endothelial dysfunction, vascular calcification, increased metalloproteinase activity, oxidative damage, and collagen degradation.
A systematic literature review and meta-analysis (18 randomized controlled trials, 912 participants) showed that oral lipoic acid significantly reduced c-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor α levels (TNF-α) in patients with metabolic syndrome and related diseases. Note 3
*Conclusion: Oral lipoic acid can improve a variety of inflammatory markers, but limited by the heterogeneity of the studies included and the small sample size, more studies are needed to support it
6. Alpha lipoic acid helps with weight loss
To date, more than 21.30 billion people, or nearly <>% of the global population, are overweight or obese. Therefore, obesity can be seen as a global epidemic and a major public health problem.
Overweight and obesity are characterized by high levels of body fat, which increases the risk of cardiovascular disease, certain cancers, and overall mortality.
For overweight individuals, successful weight loss is defined as the loss of 10% or more of their initial body weight and maintenance for more than one year.
A literature review and meta-analysis (including 12 placebo-controlled clinical trials) showed that alpha lipoic acid supplementation was beneficial in reducing body weight (-0.69 kg) and body mass index/BMI (-0.38 kg), but had no significant effect on waist circumference. Note 4
Subgroup analysis found that the effect of weight loss was most significant in those with less than 10 weeks of use, daily dose of less than 600 mg and overweight.
*Conclusion: Alpha lipoic acid supplementation has a small but statistically significant effect on weight loss and body mass index improvement
7. Alpha lipoic acid improves burning mouth syndrome
Burning mouth syndrome is a complex disease characterized by a feeling of warmth or burning sensation in the oral mucosa, without obvious mucosal changes or lesions, such as mouth pain, tongue pain, neuropathic pain, glossitis, burns, etc
The prevalence of burning mouth syndrome is between 0.7% ~ 4.6% of the general population, increasing with age, mainly affecting menopausal women (up to 18% to 33%)
Possible causes include hormonal changes, psychological factors (including anxiety, depression, stress, life events), and salivary gland dysfunction
One randomized, double-blind, placebo-controlled study (8 weeks in 60 patients with burning mouth syndrome) noted that oral lipoic acid (800 mg daily) did not significantly help improve symptoms (as measured by Visual Analogue Scale). Note 5
*Conclusion: Alpha lipoic acid has not brought significant benefits in improving burning mouth syndrome, which needs to be further verified by more studies
What are the food sources of alpha lipoic acid?
Alpha lipoic acid can be found in natural foods covalently bound to lysine, such as vegetables (spinach, cauliflower, tomato) and meat (especially red meat or animal offal), and can also be formed by enzyme conversion of octanoic acid and thiocysteine (cysteine) in animal and plant mitochondria.
How to take alpha lipoic acid (in what dose)?
Regarding the dose of lipoic acid, most evidence suggests that 100 to 600 mg is sufficient and safe, but it varies by type (S, R, or sodium combined with R), and absorption is higher when taken on an empty stomach.
People with diabetic complications or cognitive impairment may need more lipoic acid, in which case it is best to consult a doctor about their physical condition before use.
How to choose alpha lipoic acid?
R-lipoic acid (R-lipoic acid) is the only natural form that can be used by the human body, but there are two types of lipoic acid available on the market, namely alpha lipoic acid (artificial S + natural R formula) and R lipoic acid (natural R formula).
Studies have also found that the concentration of drugs in the blood after taking R lipoic acid is not only double that of artificial S formula (Note 10), but also has a reaction speed that is 60% higher (compared to artificial S formula), so it is more beneficial to choose R Formula (R-Lipoic Acid).
At present, the pharmaceutical industry has developed the second generation of natural R-lipoic acid, which combines sodium with R formula to become sodium-R-lipoic acid (NaRLA), which can solve the polymerization problem, in addition to improving stability, but also increase blood concentration by 10-30 times. Note 11
Are there any side effects of alpha lipoic acid?
In general, appropriate doses of lipoic acid are generally considered safe, but possible mild side effects and adverse effects that have been reported include: skin allergic reactions, including rash, urticaria and itching, abdominal pain, nausea, vomiting, diarrhea, dizziness, foul smell of urine, etc., especially in large doses (1200 mg to 1800 mg). Note 6
Safety precautions
1. There has been a rare case of refractory convulsions caused by children taking unknown doses of lipoic acid. Note 7
2. There has been a case of a man (with diabetes, peripheral neuropathy and mild chronic renal failure) taking high doses of lipoic acid (600 mg/day) resulting in acute cholestatic hepatitis. Note 8
3. High-dose lipoic acid (600 mg/day) reduces blood iron levels and is thought to possibly trigger iron deficiency anemia, but despite this, no such events have been reported in humans. Note 9
4. Biotin’s chemical structure is similar to alpha lipoic acid, and there is evidence that high concentrations of lipoic acid may compete with biotin for transport across cell membranes and reduce the activity of two biotin-dependent enzymes, but it is unclear whether oral or intravenous lipoic acid supplements significantly increase the body’s need for biotin
5. Do not use if you are pregnant, lactating or have poor liver and kidney function (due to unknown safety)
6. Do not use by children and infants (may cause unknown risks)
7. Stop using 2 weeks before surgery (as it may affect blood sugar control)
8. Do not use it in combination with thyroid treatment drugs, which may interfere with the effectiveness of the drugs
9. Do not combine with cancer chemotherapy drugs, which may interfere with drug efficacy (because antioxidants may reduce the effectiveness of certain cancer drugs)
10. Do not use it with insulin or oral diabetes drugs, it may cause blood sugar to be too low (because lipoic acid has a hypoglycemic effect), related drug names are: glimepiride, glyburide, insulin, pioglitazone, rosiglitazone, chlorpropamide, glipizide, tolbutamide