Duane Mellor is a director, council member and spokesperson of the British Dietetic Association
Nenad Naumovski, Said Ajlouni, and Senaka Ranadheera do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Yoghurt is one of the oldest fermented dairy foods in the world. Its origins date back to the dawn of civilisation. When humans began domesticating animals for milk production, milk’s short shelf life required solutions for storing it.
The word “yoghurt” itself comes from Turkish, meaning something like “curdled” or “thickened milk”, which is pretty much what happens to milk during yoghurt production.
Like milk, yoghurt is a rich source of calcium and protein. And it provides other nutrients such as iodine, vitamins D, B2 and B12, and zinc.
But yoghurt is actually more nutritious than milk. The main reason is that the fermentation process makes it easier to digest, so the nutrients can be absorbed more easily into the body.
Yet with all the various types, like Greek and liquid yoghurts, and ones with added fruits and probiotics, how do you know which one is healthiest?
Making yoghurt
Yoghurt is made by introducing certain bacteria into fresh milk – typically Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus.
Usually, both these bacteria are present in yoghurt and form the yoghurt starter culture. Their synergistic relationship is a key factor in the consistency of the final product. These cultures may also provide some health benefits, such as reducing the severity and duration of diarrhoea.
The bacteria ferment the naturally occurring milk sugar (lactose) for energy and growth. During this process, lactose becomes lactic acid. The acidity development leads to the main milk protein, casein, breaking down and losing some of its elementary structure.
This partial breakdown results in the semi-solid, gel-like structure we know as yoghurt. The lactic acid is also responsible for yoghurt’s sour flavours, as well as helping it stay fresher for longer than milk.
What makes yoghurt healthy?
Yoghurt is easier to digest than milk because enzymes involved in the fermentation process break down substances, such as lactose, into smaller compounds, which can be readily absorbed and used by the body. And certain minerals, such as calcium, phosphorus and iron, are better used by the body when they come from yoghurt.
And because lactose is broken down and converted to lactic acid during fermentation, lactose-intolerant people can consume yoghurt without adverse effects.
Consuming yoghurt is associated with many health benefits, including maintaining a healthy microbiota (the colony of bacteria in your gut). Yoghurt can feed the good bacteria and help them fight against disease-causing microorganisms.
Yoghurt consumption helps to maintain bone structure and has even been found to reduce the risk of certain cancers and infectious diseases, as it enhances the immune response. Yoghurt can help reduce symtpoms of conditions such as constipation, inflammatory bowel disease, infection with a bacterium that can damage the stomach lining (Helicobacter pylori), diarrhoeal diseases and some allergic reactions, such as to certain foods.
Types of yoghurt
Cow’s milk is the most widely used raw ingredient for yoghurt manufacturing. But other types, such as sheep and goat milk yoghurt, are available. There are slight differences in the nutritional composition among these milk types.
Although cow’s milk is generally more appealing (as goat and sheep milk may have unpleasant smells), the latter two may provide additional health benefits. For instance, goat’s milk is easier to digest than cow’s milk and is less likely to cause an allergic reaction.
Non-dairy alternatives such as soy and coconut milk yoghurt are becoming increasingly popular too.
Goat’s milk is easier to digest than cow’s milk.from shutterstock.com
The most commonly known types of yoghurt are plain set yoghurt, flavoured yoghurt, Greek yoghurt, frozen yoghurt and drinking yoghurt.
Plain set yoghurt is usually made from dairy ingredients and fermented in the cups or tubs with no sugar or sweeteners.
Flavoured yoghurt is made by adding sugar and fruit or other flavourings to plain yoghurt. Often, the milk mixture is fermented in large vats, cooled and then stirred for a creamy texture with various fruits or other flavours. These stirred yoghurts are also known as Swiss-style yoghurts.
Greek yoghurt is a thick yoghurt. It’s traditionally prepared by straining the water known as whey from plain yoghurt to make it thicker, richer and creamier. It contains more protein than regular yoghurt and has no added sugar.
Frozen yoghurt is frozen ice milk with a typical yoghurt flavour. It tastes more like ice-cream with a hint of yoghurt.
Drinking yoghurts are prepared from a yoghurt mix with reduced milk solids. They come in almost every variety and flavour. They’re usually more watery, but some thick varieties are also available. Kefir and lassi are the popular drinking yoghurt types.
Added ingredients for health purposes
Many yoghurts contain added ingredients. These include cholesterol-lowering compounds (such as stanol and sterol esters) and fibre aimed at improving gut health.
Some yoghurts also have added probiotics. These are live microorganisms that can help establish a healthy gut microbiota. The most widely used probiotics are the acidophilus strain, known as Lactobacillus acidophilus, and Bifidobacterium. These could be useful for people who have gastrointestinal problems such as irritable bowel syndrome (IBS).
The two bacteria in yoghurt starter culture – S. thermophilus and L. delbrueckii ssp. bulgaricus – are not natural inhabitants of the intestine and cannot survive the acidic conditions and bile concentrations in the gastrointestinal tract. So they don’t do much to change the microbiota in your gut. In contrast, probiotics can survive and colonise the large intestine.
It’s healthier to add your own fruit to yoghurt than to buy fruity yoghurt.Peter Hershey/Unsplash
Regular intake of yoghurt that contains microbial cultures such as probiotic acidophilus has also been found to potentially reduce the risk of coronary heart disease by helping to decrease cholesterol absorption.
Which yoghurt is better for you?
When whole milk is used to produce plain yoghurts, these may contain 3.5-4.4 grams of fat per 100g. Low-fat yoghurt contains less than 3g of fat per 100g, and non-fat or fat-free yoghurts must contain less than 0.15g fat per 100g.
High fat and high sugar in any food can lead to health problems. So, a low-fat and low-sugar yoghurt product, like a low-fat Greek yoghurt, would be ideal if you’re looking to keep healthy.
Yoghurt products incorporating fruit or nuts can provide additional nutritional and health benefits, but many of these can also contain added sugar. Adding fresh fruit or nuts to a yoghurt yourself is a healthier option.
If you would like to have probiotic effects, you can choose a product with acidophilus or bifidobacteria.
You should check the product label as it is a legal requirement to list all the ingredients, cultures and nutritional information in commercial yoghurts. When it comes to probiotic yoghurts, it’s always better to choose a fresh product rather than one closer to the expiry date, as probiotics die during storage.
a Obstetrics and Gynecology , University of Helsinki and Helsinki University Hospital , Helsinki , Finland.
Abstract
Coronary artery disease (CAD) is still the most common killer of western women. Coronary arteries, expressing estrogen receptors, are a target for estrogen action. Prior to the Women’s Health Initiative (WHI) study, postmenopausal hormone therapy (HT) was widely advocated for primary prevention of CAD, but such use was criticized after the WHI publication. However, new data accumulated in the USA and in Europe indicate that the use of estradiol-based HT regimens does not endanger the heart, but rather, it significantly reduces the incidence of CAD events and mortality. This effect may be related to the presence of hot flushes before HT initiation, because they may indicate a greater responsiveness of the cardiovascular system to HT. To get maximal cardioprotective efficacy of HT, a woman should initiate HT as soon as symptoms occur, and preferably within the first 10 postmenopausal years. Recent guidelines for optimal use of HT recommend pauses of HT at 1-2-year intervals to see whether hot flushes and other symptoms still persist. However, new data question the safety of this policy, because acute withdrawals of estradiol from the circulation may predispose to potentially fatal CAD events. All these data support modernized guidelines for optimal HT use.
In fact, reading this again, they agree that cheese is good for you. So i can go back to my smelly cheeses with a glass of red. Good news. Look at the explanation for the full details.
Associate Professor of Dietetics, Swinburne University of Technology
Almost everyone loves a good vegemite and cheddar sandwich or some brie with a glass of wine. But the evidence seems to shift about whether or not cheese should be part of a healthy diet.
Most types of cheese contain salt and saturated fat, but it’s also high in protein and calcium, so what’s the verdict?
We asked five experts if cheese is bad for our health.
If you have a “yes or no” health question you’d like posed to Five Experts, email your suggestion to: alexandra.hansen@theconversation.edu.au
Disclosures: Rebecca Reynolds owns The Real Bok Choy, a nutrition and lifestyle consultancy.
Clare Collins is affiliated with the Priority Research Centre for Physical Activity and Nutrition, the University of Newcastle, NSW. She is an NHMRC Senior Research and Gladys M Brawn Research Fellow. She has received research grants from NHMRC, ARC, Hunter Medical Research Institute, Meat and Livestock Australia, Diabetes Australia, Heart Foundation, Bill and Melinda Gates Foundation, nib foundation. She has consulted to SHINE Australia, Novo Nordisk, Quality Bakers and the Sax Institute. She was a team member conducting systematic reviews to inform the Australian Dietary Guidelines update and 2017 evidence review on dietary patterns for the Heart Foundation.
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t=arguments.length,n=Array(t>1?t-1:0),o=1;o https://theconversation.com/assets/runtime-35cf524207974d2ad30a.jshttps://platform.twitter.com/widgets/widget_iframe.7a5ca036ea5299f1d2ebb2234731e35e.html?origin=https%3A%2F%2Ftheconversation.com&settingsEndpoint=https%3A%2F%2Fsyndication.twitter.com%2Fsettings
This is good news for you coffee lovers. Our thinking about coffee has radically changed over the last 10 years – we now recognize coffee’s many benefits.
J Int Soc Sports Nutr. 2018 Mar 5;15:11. doi: 10.1186/s12970-018-0216-0. eCollection 2018.
Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis.
Caffeine is commonly used as an ergogenic aid. Literature about the effects of caffeine ingestion on muscle strength and power is equivocal. The aim of this systematic review and meta-analysis was to summarize results from individual studies on the effects of caffeine intake on muscle strength and power.
Methods:
A search through eight databases was performed to find studies on the effects of caffeine on: (i) maximal muscle strength measured using 1 repetition maximum tests; and (ii) muscle power assessed by tests of vertical jump. Meta-analyses of standardized mean differences (SMD) between placebo and caffeine trials from individual studies were conducted using the random effects model.
Results:
Ten studies on the strength outcome and ten studies on the power outcome met the inclusion criteria for the meta-analyses. Caffeine ingestion improved both strength (SMD = 0.20; 95% confidence interval [CI]: 0.03, 0.36; p = 0.023) and power (SMD = 0.17; 95% CI: 0.00, 0.34; p = 0.047). A subgroup analysis indicated that caffeine significantly improves upper (SMD = 0.21; 95% CI: 0.02, 0.39; p = 0.026) but not lower body strength (SMD = 0.15; 95% CI: -0.05, 0.34; p = 0.147).
Conclusion:
The meta-analyses showed significant ergogenic effects of caffeine ingestion on maximal muscle strength of upper body and muscle power. Future studies should more rigorously control the effectiveness of blinding. Due to the paucity of evidence, additional findings are needed in the female population and using different forms of caffeine, such as gum and gel.
I return to work today after a 3 week break, refreshed and ready to resume doing what I enjoy doing so much – helping with hormonal problems. I was in Singapore and Bintan Island while away – the weather was great, the people lovely, and I gained too many kilos ( the down side of holidays) I will just have to get onto a diet – more on that later.
Consultant Dermatologist, St Vincent’s Hospital Melbourne
Disclosure statement
Cara McDonald consults to La Roche Posay.
Makeup is an everyday item for many people and non-negotiable for some. Is it bad for our skin? As always, the answer is not clear-cut and depends on the individual, their skin type, and the products they use.
With an overwhelming choice of cosmetic products available, most people don’t even know where to start with makeup. Organic? Natural? Fragrance free? Hypoallergenic? Non-comedogenic? Paraben free? What does this all mean, and are they any better?
The term makeup generally describes the group of cosmetics that are used for beautification. Other cosmetics include products that are used to cleanse, treat or protect the skin and hair. These days, though, we commonly see all-in-one products, such as BB or CC creams, which combine makeup for coverage together with other ingredients to provide sun protection and skin benefits. Reducing the total number of products can be helpful for those with problematic skin, but may complicate things for some.
What does makeup do to our skin?
While in most cases makeup is harmless, certain products may cause problems for some individuals. It’s very important to use makeup and cosmetics that are suitable for your skin type or skin condition.
Skin types are broadly classified into four groups:
• oily – excess oil production, large pores, blackheads and acne prone
• sensitive – tight, stinging, intolerant to many products and prone to redness
• dry – dull, rough or flaky and prone to itchiness
• normal/combination – may be oily in the T-zone (forehead, nose and chin) but problem-free elsewhere
Although most people have a good idea of their basic skin type, they may fail to recognise the existence of an underlying skin disorder. Conditions such as eczema, contact dermatitis, rosacea and sun damage may cause inflammation and disruption of the skin barrier.
Inflammation causes itchiness or tenderness, redness, lumps and bumps, while barrier disruption results in tight, sensitive, dry and easily-irritated skin. These symptoms can be identical to those caused by reactions to cosmetics, and therefore should be considered before assuming makeup to be the cause. Conversely, an ongoing reaction to products being applied to the skin may explain why the skin is not responding to regular treatment.
Acne cosmetica is a form of acne triggered by the use of certain cosmetic products. It is linked to certain ingredients that cause comedone formation (a blockage in the pore) and typically presents as small rash-like bumpy pimples. A common misconception is that the makeup physically blocks the pore, whereas actually the block is made of dead skin cells.
Mild inflammation results in excess skin turnover and clogging of the pore, with mineral oils being the most common culprit. It’s not always possible to determine makeup is the cause simply from the ingredient list, as it may be influenced by formulation, quantity and delivery methods.
Irritant dermatitis accounts for the majority of reactions to makeup and other cosmetic products. It can occur in anyone but is more likely in those with pre-existing sensitive skin or in those with underlying barrier disruption caused by a condition like eczema or rosacea. It typically causes an itchy, scaly red rash but can even blister or weep. Symptoms can occur immediately but may take weeks or even months to develop with weaker irritants, making it difficult to identify the cause.
Allergic contact dermatitis occurs when a person has become sensitised to an ingredient that has been applied to the skin. A red, itchy rash sometimes associated with swelling or blisters develops 12-48 hours after exposure, and may become chronic with ongoing use. The allergen can be very difficult to identify, because in some cases the product is used for months or years before sensitisation occurs.
People put many different products on their face, isolating a cause of irritation can be tricky.from http://www.shutterstock.com
Are there ingredients we should avoid?
Fragrances and preservatives are the most common cause of contact allergy resulting from cosmetics. There are over 5,000 different fragrances used in skin care products, many of which are natural plant extracts and essential oils.
Other common allergens include preservatives, lanolin, coconut diethanolamide (a foaming agent) and sunscreen agents. Preservatives, such as parabens, formaldehyde and Quaternium-15 are required in all liquid products to stabilise them and prevent the growth of microbes. A common misconception is that natural and organic ingredients will not cause allergy or irritation, but in prone individuals these can in fact be quite problematic.
Unless you have a known allergy or sensitivity, there are no specific ingredients that everyone should avoid. But looking for hypoallergenic, fragrance-free and non-comedogenic products is wise. Those with an oily skin type or a history of acne should also limit oil-based cosmetics.
Those with a sensitive or dry skin type, an underlying inflammatory skin condition or history of contact allergy should try to avoid irritants and potential allergens. Foaming agents, astringent products (such as toners that remove oils), scrubs and acids (such as alpha hydroxy acids used in acne and anti-ageing) tend to be irritating. Hypoallergenic formulations and those targeting sensitive skin are a good choice.
What should I do if I think I might have a reaction?
If you develop a new rash or skin irritation, the first thing to do is to try to confirm the diagnosis. If you suspect you are reacting to one of your cosmetics but not sure which, then ideally you need to stop using all your current products in the problem area. You should try to simplify your daily routine, choosing products that have been specifically formulated for sensitive and allergic skin.
If the problem settles, you can reintroduce your cosmetics one at a time to see whether you can identify the culprit. It’s a good idea to test each one in a small localised area on the neck or face for a week or two before using it all over the face. This process is known as a “repeat open application test”.
If you can’t get to the bottom of it or find cosmetics that don’t irritate your skin, you may need to seek professional help to rule out other skin conditions and formally test for allergies if warranted
Dr Colin Holloway 
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