Life Extension Magazine®

Q & A

Garlic for your pet?, Taking pregnenolone and more.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, in January 2021. Written by: Life Extension Editorial Staff.


Q: Thank you for your article on pet nutrition. I have a concern, however. You say that onions are dangerous for dogs, and especially cats. However, my son gives his animals garlic as a flea deterrent. Since onions and garlic are in the same family, is this dangerous? Many pet products contain garlic.

A: We asked veterinarian, Dr. Richard Palmquist, to comment. Onions contain sulfur compounds, including N-propyl disulphide, which interfere with an enzyme in the red blood cells of cats and dogs. If given in high enough amounts, or for prolonged periods, the animals can develop hemolytic anemia and eventually die. Cats and some breeds of dogs are the most susceptible. Raw garlic, and garlic processed to retain its oil-soluble sulfur compounds, contain similar substances, including allicin, which can also damage red blood cells. The concept of using smelly garlic as a flea repellant in pet products is an interesting idea. However, the smelly part of garlic contains the sulfur compounds which have the potential to damage blood cells and cause bleeding in the gut. Aged garlic extract (Kyolic) contains primarily water-soluble garlic compounds, and is safe for animals. Although there isn’t enough garlic in most pet products to cause harm, the benefits of garlic as a flea repellant are not proven. Dr. Palmquist advises that he has never experienced a problem in healthy dogs and cats, but if there are any doubts, consult with your animal’s veterinarian.

Q: On your website I found some information about pregnenolone capsules that appears to conflict with what my doctor tells me. My 58-year-old wife is using 50 mg of pregnenolone per day. However, she underwent an operation some years ago to remove the majority of a meningioma, and various articles and doctors state that progesterone has a stimulating influence on these tumors. In your bullet list for pregnenolone you mention that it is “readily converted into progesterone.” Yet my doctor always stated that pregnenolone is harmless. He refers to the biochemical fact that exogenous pregnenolone cannot reach the gland cells that contain the enzymes to do the conversion to progesterone. Only endogenous pregnenolone (which is produced in these cells) will convert readily. So in this view your statement is correct, but not applicable for pregnenolone from capsules. What is your opinion on this? Also, how can pregnenolone work out positively on the bone mass? Isn’t this an estrogenic effect only, or does pregnenolone support it as well? It might be crucial in our choice for enjoying the benefits of pregnenolone without the fear of tumor growth.

A: Technically, pregnenolone should cascade down to progesterone. Since nobody really knows how your body is going to convert that hormone, as opposed to the next person, the only way to know if your wife is converting it to progesterone is to have a blood test. Have a blood test before supplementing with pregnenolone and then have another one month later to see if her progesterone levels have risen. Both hormones—estrogen and progesterone—are necessary for bone formation. Estrogen builds osteoclast cells, while progesterone builds osteoblasts cells. These two cells are necessary for proper bone formation. In a study published in the journal Endocrinology (1998, Vol 139, No 10), the ovaries of female rats were removed for the purpose of inducing an estrogen and progesterone deficiency. The effects of estrogen-progesterone ablation was a severe 90% reduction in tibial bone and a 43% reduction in vertebral bone. This structural deterioration of bone was seen throughout the skeleton and provides an acute view of the catabolic effects of hormonal deprivation.


Q: When you state that glutamine is synthetically produced, what do you mean? Is it a chemical? How is it made?

A: The process is called recombinant DNA technology. It starts with the DNA of a yeast cell put it into a broth or soup of specific nutrients and from there it makes glutamine. All of our amino acids are synthetically produced in a lab.

Q: I have calcium deposits in my hips. What would you recommend for the reduction or elimination of this calcification? I have had cortisone shots in the past and would prefer not to repeat the process.

A: You need to find out why this is happening. Are you low in magnesium? Are your vitamin K levels low? Why are you not absorbing calcium? You should get a blood test to check out your parathyroid hormone levels, ionized calcium, vitamin K and magnesium. Also, get an acid base test. You may not be able to break down and absorb calcium, which then gets stored in your bones and other places. As far as getting rid of the calcium that is currently stored, you could try ACID-A-CAL. When taken as directed, this product works very well for bone spurs.