In this extremely popular and numerously mirrored lecture, Dr. Michael Greger presents "proofs" that humans should not consume dairy milk and meat at all, because it is destructive to health in numerous aspects, and by drinking it we effectively shorten our lifespan.

For example, re. cancer, between time 20:58 and 21:30 he asks "how low does our consumption of animal products have to go?" and answers that "only vegans" (not "vegetarians" or "meat-eaters") have significantly lower levels of circulating IGF-1.

Are dairy milk and meat destructive to human health? Does the average human live longer if dairy milk and meat is abstained?

  • This is a 55 minute video. Can you please transcribe a relevant quote, with a timecode, so we don't all have to watch the entire video to find it? – Oddthinking May 11 '15 at 10:10
  • The lecture includes arguments like, people die of heart attacks when they're measured as having normal or optimal levels of cholesterol ... therefore the "normal" level of cholesterol is too high. So it's a complicated message with several parts to it. – ChrisW May 11 '15 at 10:11
  • @oddthinking: That's a good point, there are so many claims in that video. I was considering quoting the relevant parts and putting them in a list. – Hello World May 11 '15 at 10:11
  • I'm wary of lists, because it often makes it too broad to answer. Pick one, and then ask separate questions for the others. – Oddthinking May 11 '15 at 10:13
  • 1
    @oddthinking: You are right, it's essentially an identical question. Feel free to mark as duplicate. – Hello World May 11 '15 at 16:53

Dairy milk:

Nutritionstudies.org cited 12 facts about dairy milk:

1. In observational studies both across countries and within single populations, higher dairy intake has been linked to increased risk of prostate cancer (cited in [2]).
2. Observational cohort studies have shown higher diary intake is linked to higher ovarian cancer risk (cited in [2]).
3. Cow’s milk protein may play a role in triggering type 1 diabetes through a process called molecular mimicry[3].
4. Across countries, populations that consume more dairy have higher rates of multiple sclerosis[4].
5. In interventional animal experiments and human studies, dairy protein has been shown to increase IGF-1 (Insulin-like Growth Factor-1) levels. Increased levels of IGF-1 has now been implicated in several cancers[5].
6. In interventional animal experiments[6] and human experiments[7], dairy protein has been shown to promote increased cholesterol levels (in the human studies and animal studies) and atherosclerosis (in the animal studies).
7. The primary milk protein (casein) promotes cancer initiated by a carcinogen in experimental animal studies[8].
8. D-galactose has been found to be pro-inflammatory and actually is given to create animal models of aging[1].
9. Higher milk intake is linked to acne[9].
10. Milk intake has been implicated in constipation[10] and ear infections (cited in [2]).
11. Milk is perhaps the most common self-reported food allergen in the world[11].

References cited:

  1. Michaelsson K, Wolk A, Langenskiold S, et al. Milk intake and risk of mortality and fractures in women and men: cohort studies. Bmj 2014;349:g6015.
  2. Lanou AJ. Should dairy be recommended as part of a healthy vegetarian diet? Counterpoint. The American journal of clinical nutrition 2009;89:1638S-42S.
  3. Dahl-Jorgensen K, Joner G, Hanssen KF. Relationship between cows’ milk consumption and incidence of IDDM in childhood. Diabetes Care 1991;14:1081-3.
  4. Malosse D, Perron H, Sasco A, Seigneurin JM. Correlation between milk and dairy product consumption and multiple sclerosis prevalence: a worldwide study. Neuroepidemiology 1992;11:304-12.
  5. Key TJ. Diet, insulin-like growth factor-1 and cancer risk. Proc Nutr Soc 2011:1-4.
  6. Kritchevsky D. Dietary protein, cholesterol and atherosclerosis: a review of the early history. The Journal of nutrition 1995;125:589S-93S.
  7. Gardner CD, Messina M, Kiazand A, Morris JL, Franke AA. Effect of two types of soy milk and dairy milk on plasma lipids in hypercholesterolemic adults: a randomized trial. Journal of the American College of Nutrition 2007;26:669-77.
  8. Youngman LD, Campbell TC. Inhibition of aflatoxin B1-induced gamma-glutamyltranspeptidase positive (GGT+) hepatic preneoplastic foci and tumors by low protein diets: evidence that altered GGT+ foci indicate neoplastic potential. Carcinogenesis 1992;13:1607-13.
  9. Spencer EH, Ferdowsian HR, Barnard ND. Diet and acne: a review of the evidence. Int J Dermatol 2009;48:339-47.
  10. Caffarelli C, Baldi F, Bendandi B, Calzone L, Marani M, Pasquinelli P. Cow’s milk protein allergy in children: a practical guide. Italian journal of pediatrics 2010;36:5.

  11. Rona RJ, Keil T, Summers C, et al. The prevalence of food allergy: a meta-analysis. J Allergy Clin Immunol 2007;120:638-46.

Meat: Not to forget here that meat contains vitamins, minerals, antioxidants and various other nutrients that can have profound effects on health.

My studies showed that red meat consumption is associated with an increased risk of cancer. For example:

A study also showed that red meat is linked to shorter lifespan:

A new study adds to the evidence that eating red meat on a regular basis may shorten your lifespan. The findings suggest that meat eaters might help improve their health by substituting other healthy protein sources for some of the red meat they eat.

The report goes on and say:

Almost 24,000 participants died during the study, including about 5,900 from cardiovascular disease and about 9,500 from cancer. Those who consumed the highest levels of both unprocessed and processed red meat had the highest risk of all-cause of mortality, cancer mortality and cardiovascular disease mortality.

Another study, published in Archives of Internal Medicine, said:

We found that a higher intake of red meat was associated with a significantly elevated risk of total, cardiovascular disease, and cancer mortality. [...] This association was observed for unprocessed and processed red meat with a relatively greater risk for processed red meat.

Another study found that:

Diets high in meat, eggs and dairy could be as harmful to health as smoking.

Another study also found that: Meat and cheese may be as bad for you as smoking.

A high-protein diet during middle age makes you nearly twice as likely to die and four times more likely to die of cancer, but moderate protein intake is good for you after 65. But how much protein we should eat has long been a controversial topic -- muddled by the popularity of protein-heavy diets such as Paleo and Atkins. Before this study, researchers had never shown a definitive correlation between high protein consumption and mortality risk.

Not to forget that: Correlation does not imply causation.

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  • When you added "Correlation does not imply causation", are you claiming that the references which you cited do not demonstrate causation? – ChrisW May 11 '15 at 11:40
  • @ChrisW, correct. – Shougo Makishima May 11 '15 at 11:41
  • Some elements of the lecture seem to claim causation: for example it said that a vegan diet lowers IGF-1 which has an effect on cancer in vitro ... and that re-adding an IGF-1 supplement negates that effect on the cancer (allegedly proving that it's the IGF-1 level that's the causal agent). – ChrisW May 11 '15 at 11:44
  • That's just one example: he claims several, various causal mechanisms for different diseases. – ChrisW May 11 '15 at 11:46
  • xkcd.com/552 -- "Correlation doesn't imply causation, but it does waggle its eyebrows suggestively and gesture furtively while mouthing 'look over there'." – ChrisW May 11 '15 at 11:48

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