Some Experts Caution against Using Alpha Lipoic Acid with Cancer

Most research shows that alpha lipoic acid and its metabolite (DHLA) work selectively on cells, depending on their condition. For example, alpha lipoic acid and DHLA have antitumor effects that kill or damage cancer cells without harming healthy tissue. ^(iv.1, 33)

However, a handful of studies show that alpha lipoic acid may promote cancer under certain circumstances. These include:

Breast Cancer

Lab and animal research shows that alpha lipoic acid helps suppress cancer cell growth — including in breast cancers that overexpress HER2. However, in one study, doses of alpha lipoic acid that prevented colon cancer stimulated growth of breast tumors. The study involved an animal model for wild-type Her2/neu breast cancer. ^{(iv.18-19, 34)}

On the other hand, alpha lipoic acid has been and is still used in clinical trials involving patients with advanced breast cancer. Much higher dosages have been used than those in the above animal study, without any reports of alpha lipoic acid causing the cancer to grow. As of August, 2012 there was at least one ongoing clinical trial using alpha lipoic acid in patients with breast cancer from early through advanced stages. Patients recruited for this trial include those with both types of HER2 breast cancer (positive and negative). ^(iv.6, 35)

Liver Cancer

In a study published in 2008, animals were given a single shot of diethylnitrosamine. This chemical is a carcinogen, which means it's known to initiate changes in cells that can lead to cancer. The animals were then fed a diet deficient in both choline and methionine, with or without dietary alpha lipoic acid. The researchers found increased growth of precancerous lesions in those animals that were given the antioxidant. ^(iv.36)

When the animals were given choline supplements, increased lesion growth didn't occur. Choline is a nutrient needed to metabolize fats. When there's not enough choline to process them, fats can get deposited in the liver. In fact, a choline-deficient diet is linked to fatty liver disease, which can lead to liver cancer. ^(iv.36-37)

Other animal studies that used different animal models and variations of the conditions tested in the above study showed different results. For example:

• A study was conducted using C57BL/6 mice that were also fed a choline and methionine-deficient diet. C57BL/6 mice are a breed recognized as one of the best models for the cellular signs of fatty liver disease. In this study, dietary alpha lipoic acid prevented fatty liver disease. ^(iv.38-39)
• In rats exposed to carbon tetrachloride, 30 mg/kg of dietary alpha lipoic acid prevented liver fibrosis the toxin caused in untreated rats. Carbon tetrachloride is categorized as reasonably anticipated to be a human carcinogen. This is the same category as diethylnitrosamine used in the above study. ^(iv.40-41)
• Daily doses of alpha lipoic acid (45 or 180 g/kg of body weight) did not enhance liver tumors in rats given 10 mg/kg of body weight of diethylnitrosamine twice a week for life. ^(iv.42)