Onions

Onions are low in calories and high in vitamins B and vitamin C. They provide fiber as well as a range of minerals including potassium, calcium and magnesium. Onions have beneficial effect on diseases and are also high in amino acid sulfoxides (hence the smell). All onions are loaded with anti-inflammatory phytochemicals and antioxidants. One medium onion contains:

• 12mg vitamin C:  20% RDA
• 0.15mg of vitamin B6: 15% RDA
• 11mg magnesium: 4%
• 160mg potassium: 10% RDA

Testosterone boosting

In a study that was conducted on rodents by Iranian scientists, it was shown that onions significantly increased testosterone levels in rats. According to a research done at Tabriz University in Iran, onion juice can raise testosterone levels as much as substances like nolvadex or clomid.

It is believed that antioxidants neutralize free radicals in the testes. The researchers suspect that the antioxidants in question are probably selenium compounds found in onions, and phenols.

Onions contain potentially testosterone boosting substances such as apigening (associated with a decrease in the steroidogenic acute regulatory, StAR protein) and quercetin (UGT2B17 is an enzyme that converts testosterone into a form that can be excreted out of the body through urine. This has the effect of lowering your circulating testosterone levels. Quercetin has been shown to inhibit this enzyme's activity).