Ask the Doctor: Q&A with Dr. Greger

Answers to featured health and nutrition questions provided by Michael Greger MD and the NutritionFacts.org volunteer moderator team.

Questions are taken from the video and blog comments throughout the site. Join in the discussion and get your question featured!


Q: Might flax seeds (ALA) increase prostate cancer risk?

Flax and Prostate Cancer Risk

There are a lot discussions and articles online about the supposed connection between flax seeds (ALA) and prostate cancer – suggesting that more flax consumed = increase chance of prostate cancer. I haven’t found this issue addressed on your website (sorry if I missed it). Can you comment?...

Q: Is raw milk healthy?

Hormones in Raw vs. Pasteurized Milk

What about Raw Milk? I know the general arguments against milk as ‘Toxin’ cites above, personally I am a vegan, but what is the actual research on Raw milk vs pasteurized milk. I work in the area of local food and farmers markets and I am exposed to vegetarians and omnivores that are big...

Q: Can hibiscus tea cause coughing?

Hibiscus Tea, Blood Pressure, and Coughing

An FYI. My mother used to take Lasinopril (sp?) for high blood pressure. It gave her a terrible dry cough and she quit taking it. Then I read hibiscus tea was good for high blood pressure and bought her tea where hibiscus was the 2nd ingredient. Then one day I found one where it was all hibiscus...

Q: Is annatto food coloring safe?

Annatto Safety for Food Coloring

I’d like to know if annato is helpful, harmful, or neutral…In general, do you know of natural food dyes? I think you mentioned that in place of using the dye from the cochineal beetle that cherries could be used. I have used spinach and mint for green, and beets for red and raspberries for...

Q: Can you take hydrogen peroxide internally?

Internal Use of Hydrogen Peroxide

I have a question regarding the use of hydrogen peroxide internally. I’m not finding much information on the subject and I have a family member who’s looking into it based on some (limited) online research. Thoughts and feedback would be appreciated. organicsauce / Originally posted...

Q: What about the INTERHEART study on heart attack risk factors?

Modifiable Risk Factors for Heart Attacks

This study might also be of interest to you and your other readers: http://www.ama-med.org.ar/obesidad/Interheart-LANCET-2004.pdf. As always, your comments and insights would be most welcome. patmcneill / Originally posted on Heart attacks and cholesterol: Purely a question of...

Q: Is the new vitamin D3 spray a waste of money?

Vitamin D Spray

Dr. Greger — have you heard about the new vitamin D3 spray? What is your opinion — helpful? Harmful? Waste of money? Thanks! vfayes / Originally posted on Vitamin D supplements may be necessary Answer: Based on their current pricing, supplementing with that product would cost hundreds of...

Q: How can I preserve the anti-cancer effects of cooked garlic?

Anticancer Effects of Raw vs Cooked Garlic and Onion

Awesome video, Dr. Greger! I am left with the question of the anticancer effects of raw vs. cooked garlic and onions. I know cooking reduces some of the nutrients but have raw and cooked alliums been tested in regard to the anti-cancer effects? In other words is it important to try to consume these...

Q: Does adding baking soda to soaking beans reduce gas?

Does Adding Baking soda to soaking beans reduce raffinose

I recently heard that the reason humans produce gas after eating beans is because they contain raffinose which is a starch that is poorly digested due to a lack of the enzyme galactosidase. The MD claimed that adding baking soda to the soaking liquid reduced the raffinose. Have you heard anything...

Q: How much fruit is safe to consume?

How Much Fruit is Safe

Thank you for this fantastic, resourceful website. I’m a bit confused on how much fruit is safe to consume. The study you quote here says it’s healthy but there are other well known Doctors who say one should not consume more than 2 – 3 fruits per day. Apparently it can harm our liver and...

Q: Can restricting high glycemic foods help macular degeneration?

Preventing further development of macular degeneration

Are you familiar with research linking high glycemic foods with incidence of macular degeneration? (NY Times reported on a 7/07 study in The American Journal of Clinical Nutrition.) Is there any reason to believe that restricting high glycemic foods, adding in vinegar, or boosting antioxidants by...

Q: Are GMOs safe and are the nutrients in our crops declining?

GMOs and decreased nutrition in our foods

Please discuss GMOs and decreased nutrition in our foods.Mary Ellen / Originally posted on Nutrition education in medicine: A doctor a day keeps the apples awayAnswer:This answer is from 2012. Please see our more recent videos on GMOs here: http://nutritionfacts.org/topics/gmosFor a discussion on...

Q: Does wild rice contain the same levels of arsenic as brown rice?

Does Wild Rice contain arsenic

I eat rice 2 or 3 times a week. When i go out to eat, I eat brown rice. When I make it at home, it is generally a wild rice blend. Does wild rice contain the same levels of arsenic? Rick / Originally posted on Arsenic in Rice Answer: Wild rice appears to have levels of arsenic comparable to...

Q: Fresh fruit versus frozen–which is better?

Frozen vs Fresh Fruit

Are there published studies providing evidence about the efficacy of frozen fruit (vs fresh)? What are viable sources of acai in the US? Sambozan adds soy lecitihin to their acai product. evanbrand / Originally posted on  Pink juice with green foam Answer: I found two good studies...

Q: What’s the best low calorie sweetener?

Sugar in Cranberry Juice

I was unable to understand the name of the sweetener you suggested in the recipe for homemade cranberry juice in the video of 12/03. I’d be grateful if you could send along the spelling of the product. Don Brix / Originally posted on Pink juice with green foam Answer: “Erythritol,” a...

Q: Can Vitamin D supplements help prevent respiratory infections?

Vitamin D supplemented in Tuberculosis Cases

Your attention to Vitamin D is very relevant these months, also to the huge discussion about the use of Vitamin D supplementation in Tuberculosis in developing countries. filippodibari / Originally posted on Evolutionary argument for optimal vitamin D level Answer: Vitamin D is thought to be...

Q: Second opinion for 8-year-old with anemia?

Anemia

We recently changed to a vegan diet. We have a daughter who is 8 years old who had been feeling dizzy as well as headaches. So we decided to take her to the doctor where they did blood and urine analysis. The diagnosis was anemia. The doctor told us that animal products are necessary because they...