Cracking the egg and milk debate

Eggs and milk have had bad press, but research suggests we simply enjoy them.

16 November 2018
by Glynis Horning

Eggs and milk have been part of our human diet for thousands of years, yet about 50 years ago they fell from favour for being high in saturated fat and cholesterol, and linked to cardiovascular disease, cancers and acne.
Now both are back – recommended by many dietitians as convenient sources of quality protein and important nutrients, the fears dispelled by a slew of major studies.


EGGS


These are a good source of choline for nerve function and cell structure, antioxidants lutein and zeaxanthin for our eyes, and vitamin A, certain B vitamins, and D, says Tirsa Bezuidenhout, a registered dietitian and spokesperson for the Association for Dietetics in SA.
Eggs do indeed contain saturated fat (almost all in the yolk), she says, but at about 1.5g for a large egg it’s relatively little, especially compared to red meat. This, coupled with the protein, can leave you feeling full for longer, helping manage weight control. 
Eggs are also high in cholesterol – higher even than beef, packing about seven times more for the same amount. But this is where scientific thinking has changed significantly. Large studies have established that dietary cholesterol found in animal foods such as eggs and dairy has little effect on most people’s blood cholesterol. 


Most significantly, eggs have been shown not to contribute to cardiovascular disease. A large Harvard study found no link between up to seven eggs a week and heart disease, with the possible exception of people with diabetes. Then an analysis in the Journal of the American College of Nutrition found people eating seven eggs a week had a 12% lower risk of stroke than those eating fewer than two a week. And a review last year in the Canadian Journal of Diabetes found eating 6 to 12 eggs a week, “in the context of a heart-healthy diet”, did not raise bad cholesterol, tryglyerides or blood sugar in people with diabetes.
Up to seven eggs a week can be a healthy part of a balanced diet, says Bezuidenhout. But have them as an alternative protein to meat at a meal, not as well – and boil, poach or scramble them, rather than fry. (Always cook them thoroughly to kill any potential bacteria.)  


MILK


This is a good source of complete protein, potassium, phosphate, choline, B vitamins, iodine and especially calcium, says Bezuidenhout. Studies show the bones of children who don’t drink milk are much weaker, though it now seems dietary calcium in adulthood makes little difference to risk of bone fractures, as our bones absorb it best up to age 25-30. Rather, the keys to keeping bones strong are weight-bearing exercise and not smoking.


Calcium is also important for many other things, including blood clotting, muscle tone and nerve function, and the calcium in dairy is particularly well-absorbed. 
Websites such as Notmilk.com have claimed that the saturated fat and cholesterol in whole milk promote heart disease and cancer, but an analysis by scientists at Reading and Cardiff universities in the UK of 300 studies found people who drank about two cups of milk a day had a 15-20% lower risk of cardiovascular disease, and a lower incidence of colon cancer and diabetes. 
Milk critics have also claimed it contains residues of hormones and antibiotics given to cows, and can affect our nervous, reproductive and immune systems, but it seems the bovine growth hormone used to boost milk production needs to be injected, as digestion destroys its protein hormones – drinking the milk of hormone-treated cows can’t transfer the active form of these chemicals to your body. The American Cancer Society notes that while more research is needed, a study has estimated the additional amount of growth factor (IGF-1) that might be absorbed by humans drinking milk represents just 0.09% of the normal daily production of IGF-1 in adults.


A Reading study concluded in the Journal of the American College of Nutrition: “We found no evidence that drinking milk might increase the risk of developing any condition, with the exception of prostate cancer… There is convincing overall evidence that milk consumption is associated with an increase in survival in Western communities.”


So it seems you can safely have a glass with your eggs. Two or three glasses of milk or other dairy equivalent to three servings a day will meet most calcium requirements. But read food labels and monitor the amount of salt and sugar in dairy products, cautions Bezuidenhout: “They should have less than 5g sugar per 100g.”

IMAGE CREDIT: Gallo Images