MILK; DOES IT DO A BODY GOOD?

Milk Intake and Risk of Mortality and Fractures in Women and Men

British Medical Journal // October 28, 2014; 349; g6015; Karl Michaelsson, Alicja Wolk, Sophie Langenskiold, Samar Basu, Hakan Melhus

Following are the key take-a-ways from this article culled from the British Medical Journal.

KEY POINTS FROM THIS STUDY:

  • A diet rich in milk products is promoted to reduce the likelihood of osteoporotic fractures.
  • The objective of this study was to examine whether high milk consumption is associated with mortality and fractures in women and men. The authors evaluated 2 large Swedish cohorts, one with 61,433 women and one with 45,339 men. The mean follow-up for the women was 20.1 years. The mean follow-up for the men was 11.2 years.
  • Women who consumed 3 or more glasses of milk a day increased their risk of mortality (relative) by 93% compared to those who consumed less than one glass a day.
  • For every daily glass of milk, the increased risk of all-cause mortality went up by 15% for women and 3% for men.
  • High milk intake is associated with higher mortality in both women and men, and with higher fracture incidence in women.
  • “A high intake of milk might have undesirable effects because milk is the main dietary source of D-galactose.”
  • Chronic exposure to D-galactose is deleterious to health and is an established accelerator of aging in animals.
  • D-galactose is an established driver for premature aging, shortened life span caused by oxidative stress and chronic inflammation.
  • Patients with higher circulating levels of galactose have an increased risk for chronic diseases in adulthood, including osteoporosis.
  •  “Even a low dose of D-galactose induces changes that resemble natural aging in animals, including shortened life span caused by oxidative stress damage, chronic inflammation, neurodegeneration, decreased immune response, and gene transcriptional changes.”
  • One glass of milk comprises about 5 g of D-galactose. The D-galactose found in 1-2 glasses of milk accelerates cell death.
  • “The high amount of lactose and therefore D-galactose in milk with theoretical influences on processes such as oxidative stress and inflammation makes the recommendations to increase milk intake for prevention of fractures a conceivable contradiction.” “The increase of oxidative stress with aging and chronic low grade inflammation is not only a pathogenetic mechanism of cardiovascular disease and cancer in humans but also a mechanism of age related bone loss and sarcopenia.”
  • These authors suggest that the high content of lactose in milk “may increase oxidative stress, which in turn affects the risk of mortality and fracture.”
  •  Milk intake increases oxidative stress (free radical damage) and increases interleukin-6, a main inflammatory biomarker.
  • D-galactose supplementation in animals has been shown to increase oxidative stress and inflammation.
  • they have lower or non-existent lactose and galactose content
  • they have less pronounced induction of oxidative stress and inflammation
  • they have positive probiotic, antioxidant and anti-inflammatory effects
  • they have positive effects on effects on gut microbiota
  • Particularly noteworthy is that intake of fermented milk products such as yogurt and soured milk and cheese were associated with lower rates of fracture and mortality.”
  • For women who consumed three or more glasses of milk a day the hazard ratio for any fracture was increased 16% and for hip fracture was increased by 60%.
  • “We observed a dose dependent higher rate of both mortality and fracture in women and a higher rate of mortality in men with milk intake, a pattern not discerned with other dairy products.”
  • There are “higher mortality rates from fracture and ischemic heart disease in countries with high milk consumption.”
  • Higher milk consumption may increase the risk of certain cancers and cardiovascular disease.
  • “A higher consumption of milk in women and men is not accompanied by a lower risk of fracture and instead may be associated with a higher rate of death.”
  • “Our results may question the validity of recommendations to consume high amounts of milk to prevent fragility fractures.”