Products like cheese, milk and yoghurt are rich in iodine, a vital nutrient for the development of babies and building up the immune system of young women, says Armagh-born nutritionalist Professor Margaret Rayman. She tells Una Brankin they should be part of our daily diet.
Women and mums-to-be are risking lower IQ in their babies by reducing their dairy intake, according to a leading nutritionist.
Armagh-born Professor Margaret Rayman says iodine - a nutrient found in milk, cheese and yoghurt - is crucial to foetal brain development.
The academic claims the current trend for banning dairy from daily consumption could be harming children's development.
As if our embattled dairy farmers aren't having a bad enough time of it these days, they have the so-called clean eating brigade - including former Miss World Rosanna Davison - claiming that their produce isn't good for us.
Add to that misconception the notion that dairy foods are fattening, and you have worrying numbers - of women, in particular - lacking in the essential nutrients dairy provides.
And it's not just those depriving themselves of dairy, it's the future generation that will be affected by the resulting deficiencies, particularly in iodine, an essential component of the thyroid hormones that keep our internal systems healthy.
The negative trend was highlighted last week by Professor Margaret Rayman, a specialist in nutritional medicine at the University of Surrey, at the annual Dairy Council nutrition lecture at Ulster University.
Through painstaking research, Professor Rayman has found that iodine deficiency in pregnancy has been linked to lower IQ and reading ability in children because it is a crucial for the development of the central nervous system and bone development in foetuses and infants.
Impressionable teenage girls are also lacking in the trace mineral, which supports the immune system and is essential for the synthesis of hormones.
A lack of it can also cause or contribute to the development of hypothyroidism, goiter, mental retardation, cretinism (severely stunted physical and mental growth and deafness due to untreated congenital hypothyroidism) and certain forms of cancer.
"There's a trend among younger people to opt for soya or almond milk over dairy, which they assume to be full of calories," says Professor Rayman.
"It's fashionable to drink these alternatives, but there's no iodine in them - there's not much of anything in them - and the rise in their consumption means that some women may be missing out on this vital nutrient.
"Individuals who consume these drinks in preference to cows' milk may be at risk of iodine deficiency and unaware of the potential consequences for their babies' cognitive and motor development.
"It's very important that women ensure that they have an adequate iodine intake from dietary sources, which in the UK are mainly cows' milk and dairy products, with contributions from fish and eggs to avoid compromising their children's brain development."
Professor Rayman - born Margaret O'Riordan in Armagh in the early Sixties - recommends 250mg of iodine a day for pregnant women. The RDA for everyone else is 150mg per day for adult men and women,220 mcg for pregnant women and 290 mcg for lactating/breastfeeding women. A standard cupful of milk provides over 50mg.
"You can get it from having milk with cocoa or on cereals and in tea or coffee, too," says the professor.
"It makes no difference whether you drink full fat or skimmed. Most people drink semi-skimmed - I do.
"Once you have semi-skimmed in tea or coffee, full fat doesn't taste as good.
"It's nice on cereals though. Skimmed doesn't have a lot of taste. Iodine is richest in milk and yoghurt. And it's in goat's cheese, funnily enough. It's lowest in cottage cheese and there's none in cream - it's a fat."
Interestingly, professor Rayman advises against organic milk products for those seeking the iodine content. "It's lower in organic milk due to the cows being fed on grass and white clover," she says. "That prevents the uptake of iodine by the thyroid, which needs it."
The daughter of two teachers, professor Rayman studied chemistry at Queen's University and gained her doctorate from Oxford, where she met her mathematician husband, John.
She now lives in Guildford and lectures at Surrey University.
"We O'Riordans weren't a health-conscious family - you weren't in those days," she recalls.
"But we did have plenty of dairy. Fish - especially white fish like cod and haddock - is also a source of iodine, but we only had that once a week, on Fridays.
"I'm still not mad keen on fish. People aren't, in general, in England either.
"Dairy is a higher source of iodine and it's easier to incorporate into your daily diet.
"Kelp - seaweed - is another rich source but its levels can be dangerously high. It's better to have milk and fish."
One of the country's leading nutritionists, Professor Rayman created the UK's first university-level degree programme on nutritional medicine.
She has also been a judge on the BBC Food and Farming Awards for the last four years and gives speeches and lectures across the UK.
Helping to prevent dementia, through nutrition is another area of the academic's expertise.
Dementia affects nearly 36 million people worldwide and there are 7.7 million new cases each year.
There is growing evidence that a healthy lifestyle - and a diet including dairy milk - can help to reduce the risk of dementia.
In her book, Healthy Eating to Reduce the Risk of Dementia, Professor Rayman and a team of nutritional experts lay down guidelines and offer 100 recipes.
"Vitamin B 12 and B complex are all important in avoiding dementia and keeping it at bay," she says. "I'm over 50 and I take it in a supplement every day, as recommended by the Institute of Medicine.
"The best source of B12 is milk. People used to be fed liver for deficiency anaemia, and red meat is a good source, but not as good as milk.
"Milk releases much more B12 into the bloodstream. You don't absorb it from meat as well because of the way meat is bound.
"Vitamin E is also important in avoiding the build-up of protein on the brain, which is associated with Alzheimer's disease.
"You can get Vitamin E from things like walnuts, rapeseed oil, sesame seeds and peanuts."
It's no surprise that this top nutritionist is not a fan of a strict vegan diet. Many doctors and qualified dietitians spoke out to advise their patients against adopting Rosanna Davison's food plan, as espoused in her best-selling book Eat Yourself Beautiful, which differs from a typical vegan diet, questioning the basis for some of her more outlandish claims, linking gluten to autism and arthritis, for example.
Professor Rayman says: "Vegans are low in iodine, US studies show that clearly. Some are savvy enough to know to eat lava bread, which is high in iodine. You really do need to know what you're doing if you're vegan.
"Vegans are also low in selenium and vitamin D and B12. It's not the most healthy way to live.
"Vegetarianism is fine, but once again, you need to know what you're doing. I'm not a vegetarian."
The professor is a grandmother of five, but has the fresh complexion of someone much younger than her years.
The secret, she reveals, is simply keeping out of the sun.
She also advocates the overall health benefits of selenium, which is thought to be good for the skin.
The most selenium-rich foods include Brazil nuts, yellowfin tuna, halibut, canned sardines, grass-fed beef, boneless turkey, liver and chicken.
"Selenium is an anti-oxidant, it's inflammatory and anti-viral, it supports the immune system and fertility and reduces risk of mortality," she says.
"And vitamin B12 is important for women going through the menopause. You might get enough from fortified cereals. If not, take a supplement. I take a good B complex.
"All adults need 10mg of Vitamin D, particularly in the winter time. And of course - three portions of dairy a day."
See www.bda.uk.com/ foodfacts/Iodine
As pregnancy is the most important time for brain development, Professor Margaret Rayman and her research team have been evaluating iodine status in UK pregnant women, finding that levels of iodine are lower than the World Health Organisation (WHO) cut-off for adequacy in pregnancy.
The research found a significant association between low iodine status in mothers in early pregnancy and their children’s brain development. Children whose mothers were iodine deficient in pregnancy (67% of those surveyed) had an approximately 60% greater risk of being in the bottom quarter of scores for IQ and reading ability at eight to nine years old.
At the recent Annual Dairy Council Nutrition Lecture at Ulster University, Professor Rayman stressed that to avoid compromising their children’s brain development, women of childbearing age, who might become pregnant, need to ensure they have an adequate iodine intake from dietary sources.
In Northern Ireland we get most of our iodine intake from milk and dairy products and the increase in sales of milk-alternative drinks over recent years, which contain little or no iodine, unless fortified with iodine (which very few are) is, according to Rayman, a worrying trend.