NUTRITION - ANSWERS

Milk is better for bone health than kale and spring greens. False. Greens (other than spinach) provide plenty of well-absorbed calcium as well as vitamin K which protects against fracture.

Spinach is a poor source of calcium. True. It contains a lot of calcium, but in an unabsorbable form.

Low B12 can be bad for your heart. True. Low B12 increases a major risk factor for heart disease.

The less protein the better. False. Moderate protein (about 0.8 grams per kg of bodyweight) is best (including for bone health).

Soya causes birth defects. False. There is no good evidence for this rumour. There is, however, evidence that low B12 can cause birth defects.

Fat removed from skimmed milk is fed to pigs. False. Virtually all the fat from cow's milk finds its way to humans somehow even if it is initially removed from the milk.

Vegans have lower cholesterol levels than lacto-vegetarians. True. Vegan levels are about 10% lower than lacto-vegetarians, who are themselves about 10% lower than meat eaters.

Vegans have lower heart disease risk than lacto-vegetarians. False. It is about the same. The lower cholesterol may be counterbalanced by low B12 and low omega-3 fat in some vegan diets.

A healthy vegan diet can be improved by adding milk. False. Milk provides nothing useful that isn't provided by plants and it provides unhealthy saturated fat.

For discussion

A young vegan woman says her doctor wants to put her on thyroid medication? Could this be connected with her diet?

Yes. In the UK iodine is added to cattle feed and used as a disinfectant for cows' udders, so dairy products provide about half the iodine in the food supply. Many other countries with low iodine levels in soil use iodized salt. Low iodine intake can cause hypothyroidism, but many doctors will not think of this possibility and go straight to thyroid medication. She should discuss this with her doctor and take two kelp tablets a week if her doctor sees no problem with this.

A vegan athlete wants to increase protein intake but is allergic to soya? What should he/she do?

There are many other legumes that are rich in protein. Using nuts and seeds rather than oils and using wheat instead of rice and potatoes boosts protein.

Someone says they want to be vegan but are afraid that if they give up dairy their bones will crumble. What do you tell them?

Up until about 5000 years ago no human consumed dairy products and our prehistoric ancestors had better bones than we have. Almost all their calcium intake came from plants. Green leafy vegetables are excellent sources of calcium and other minerals and vitamins promoting bone health. The green stuff beats the white stuff hands down, but if you prefer something white then calcium-fortified soy milk is an excellent alternative that is better for bone and heart health than cow's milk.

A vegan complains they have no energy and tingling sensations in their hands? What might be causing this?

Probably low B12, but low iodine leading to hypothyroidism can also be the cause. Any symptoms of ill health should be discussed with a GP rather than self-medicated, but the GP may need help in understanding special issues for vegans.

A vegan has just been told by their doctor they have high cholesterol and high risk of heart disease? What dietary changes might help deal with this?

The doctor should check for hypothyroidism and the individual should ensure adequate iodine intake since hypothyroidism causes increased cholesterol and increases some other risk factors for heart disease. Avoiding hydrogenated fats and tropical oils (palm and coconut) improves cholesterol profile and reduces heart disease risk. Adequate B12 and folate may reduce heart disease risk substantially independently of cholesterol levels. Adequate omega-3 fatty acids (e.g. flaxseed oil) can reduce heart disease risk in high-risk individuals by over 50%, again independently of cholesterol. If good (HDL) cholesterol is low then 1-2 units of alcohol per day can be beneficial. Again, all serious health problems should be dealt with in consultation with a doctor since general principles may be inappropriate for certain individuals.

An interviewer says vegans need B12 supplements so their diet is unnatural. How do you respond?

Our great ape relatives get enough B12 from insects and soil; we prefer to spare the insects and avoid the dirt. All B12 comes from bacteria; we just get our bacterial B12 in a convenient sanitary purified form.