Olive oil is synonymous with the Mediterranean diet, and the health benefits of both are well documented.

Olive oil reduces the risk of heart disease, cancer, diabetes and premature death. Olives also contain numerous healthy nutrients.

Now evidence is mounting about the health benefits of olive leaves, including from studies in a recent review.

Here’s what’s in olive leaves and who might benefit from taking olive leaf extract.

What’s in olive leaves?

Olive leaves have traditionally been brewed as a tea in the Mediterranean and drunk to treat fever and malaria.

The leaves contain high levels of a type of antioxidant called oleuropein. Olives and olive oil contain this too, but at lower levels.

Generally, the greener the leaf (the less yellowish) the more oleuropein it contains. Leaves picked in spring also have higher levels compared to ones picked in autumn, indicating levels of oleuropein reduce as the leaves get older.

Olive leaves also contain other antioxidants such as hydroxytyrosol, luteolin, apigenin and verbascoside.

Antioxidants work by reducing the oxidative stress in the body. Oxidative stress causes damage to our DNA, cell membranes and tissues, which can lead to chronic diseases such as cancer and heart disease.

Are olive leaves healthy?

One review and analysis combined data from 12 experimental studies with 819 participants in total. Overall, olive leaf extract improved risk factors for heart disease. This included healthier blood lipids (fats) and lowering blood pressure.

The effect was greater for people who already had high blood pressure.

Most studies in this review gave olive leaf extract as a capsule, with daily doses of 500 milligrams to 5 grams for six to 48 weeks.

Another review and analysis published late last year looked at data from 12 experimental studies, with a total of 703 people. Some of these studies involved people with high blood lipids, people with high blood pressure, people who were overweight or obese, and some involved healthy people.

Daily doses were 250-1,000mg taken as tablets or baked into bread.

Individual studies in the review showed significant benefits in improving blood glucose (sugar) control, blood lipid levels and reducing blood pressure. But when all the data was combined, there were no significant health effects. We’ll explain why this may be the case shortly.

Another review looked at people who took oleuropein and hydroxytyrosol (the antioxidants in olive leaves). This found significant improvement in body weight, blood lipid profiles, glucose metabolism and improvements in bones, joints and cognitive function.

The individual studies included tested either the two antioxidants or olive leaf incorporated into foods such as bread and cooking oils (but not olive oil). The doses were 6-500mg per day of olive leaf extract.

So what can we make of these studies overall? They show olive leaf extract may help reduce blood pressure, improve blood lipids and help our bodies handle glucose.

But these studies show inconsistent results. This is likely due to differences in the way people took olive leaf extract, how much they took and how long for. This type of inconsistency normally tells us we need some more research to clarify the health effects of olive leaves.

Can you eat olive leaves?

Olive leaves can be brewed into a tea, or the leaves added to salads. Others report grinding olive leaves into smoothies.

However the leaves are bitter, because of the antioxidants, which can make them hard to eat, or the tea unpalatable.

Olive leaf extract has also been added to bread and other baked goods. Researchers find this improves the level of antioxidants in these products and people say the foods tasted better.

Is olive leaf extract toxic?

No, there seem to be no reported toxic effects of eating or drinking olive leaf extract.

It appears safe up to 1g a day, according to studies that have used olive leaf extract. However, there are no official guidelines about how much is safe to consume.

There have been reports of potential toxicity if taken over 85mg/kg of body weight per day. For an 80kg adult, this would mean 6.8g a day, well above the dose used in the studies mentioned in this article.

Pregnant and breastfeeding women are recommended not to consume it as we don’t know if it’s safe for them.

What should I do?

If you have high blood pressure, diabetes or raised blood lipids you may see some benefit from taking olive leaf extract. But it is important you discuss this with your doctor first and not change any medications or start taking olive leaf extract until you have spoken to them.

But there are plenty of antioxidants in all plant foods, and you should try to eat a wide variety of different coloured plant foods. This will allow you to get a range of nutrients and antioxidants.

Olive leaf and its extract is not going to be a panacea for your health if you’re not eating a healthy diet and following other health advice.

Evangeline Mantzioris, Program Director of Nutrition and Food Sciences, Accredited Practising Dietitian, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Parents are often faced with well-meaning opinions and conflicting advice about what to feed their babies.

The latest guidance from the World Health Organization (WHO) recommends formula-fed babies can switch to cow’s milk from six months. Australian advice says parents should wait until 12 months. No wonder some parents, and the health professionals who advise them, are confused.

So what do parents need to know about the latest advice? And when is cow’s milk an option?

What’s the updated advice?

Last year, the WHO updated its global feeding guideline for children under two years old. This included recommending babies who are partially or totally formula fed can have whole animal milks (for example, full-fat cow’s milk) from six months.

This recommendation was made after a systematic review of research by WHO comparing the growth, health and development of babies fed infant formula from six months of age with those fed pasteurised or boiled animal milks.

The review found no evidence the growth and development of babies who were fed infant formula was any better than that of babies fed whole, fresh animal milks.

The review did find an increase in iron deficiency anaemia in babies fed fresh animal milk. However, WHO noted this could be prevented by giving babies iron-rich solid foods daily from six months.

On the strength of the available evidence, the WHO recommended babies fed infant formula, alone or in addition to breastmilk, can be fed animal milk or infant formula from six months of age.

The WHO said that animal milks fed to infants could include pasteurised full-fat fresh milk, reconstituted evaporated milk, fermented milk or yoghurt. But this should not include flavoured or sweetened milk, condensed milk or skim milk.

Why is this controversial?

Australian government guidelines recommend “cow’s milk should not be given as the main drink to infants under 12 months”. This seems to conflict with the updated WHO advice. However, WHO’s advice is targeted at governments and health authorities rather than directly at parents.

The Australian dietary guidelines are under review and the latest WHO advice is expected to inform that process.

OK, so how about iron?

Iron is an essential nutrient for everyone but it is particularly important for babies as it is vital for growth and brain development. Babies’ bodies usually store enough iron during the final few weeks of pregnancy to last until they are at least six months of age. However, if babies are born early (prematurely), if their umbilical cords are clamped too quickly or their mothers are anaemic during pregnancy, their iron stores may be reduced.

Cow’s milk is not a good source of iron. Most infant formula is made from cow’s milk and so has iron added. Breastmilk is also low in iron but much more of the iron in breastmilk is taken up by babies’ bodies than iron in cow’s milk.

Babies should not rely on milk (including infant formula) to supply iron after six months. So the latest WHO advice emphasises the importance of giving babies iron-rich solid foods from this age. These foods include:

• meat
• eggs
• vegetables, including beans and green leafy vegetables
• pulses, including lentils
• ground seeds and nuts (such as peanut or other nut butters, but with no added salt or sugar).

You may have heard that giving babies whole cow’s milk can cause allergies. In fact, whole cow’s milk is no more likely to cause allergies than infant formula based on cow’s milk.

What are my options?

The latest WHO recommendation that formula-fed babies can switch to cow’s milk from six months could save you money. Infant formula can cost more than five times more than fresh milk (A$2.25-$8.30 a litre versus $1.50 a litre).

For families who continue to use infant formula, it may be reassuring to know that if infant formula becomes hard to get due to a natural disaster or some other supply chain disruption fresh cow’s milk is fine to use from six months.

It is also important to know what has not changed in the latest feeding advice. WHO still recommends infants have only breastmilk for their first six months and then continue breastfeeding for up to two years or more. It is also still the case that infants under six months who are not breastfed or who need extra milk should be fed infant formula. Toddler formula for children over 12 months is not recommended.

All infant formula available in Australia must meet the same standard for nutritional composition and food safety. So, the cheapest infant formula is just as good as the most expensive.

What’s the take-home message?

The bottom line is your baby can safely switch from infant formula to fresh, full-fat cow’s milk from six months as part of a healthy diet with iron-rich foods. Likewise, cow’s milk can also be used to supplement or replace breastfeeding from six months, again alongside iron-rich foods.

If you have questions about introducing solids your GP, child health nurse or dietitian can help. If you need support with breastfeeding or starting solids you can call the National Breastfeeding Helpline (1800 686 268) or a lactation consultant.

Karleen Gribble, Adjunct Associate Professor, School of Nursing and Midwifery, Western Sydney University; Naomi Hull, PhD candidate, food security for infants and young children, University of Sydney, and Nina Jane Chad, Research Fellow, University of Sydney School of Public Health, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

It’s that time of year when many people are getting started on their resolutions for the year ahead. Doing more physical activity is a popular and worthwhile goal.

If you’re hoping to be more active in 2024, perhaps you’ve invested in an activity tracker, or you’re considering buying one.

But what are the benefits of activity trackers? And will a basic tracker do the trick, or do you need a fancy one with lots of features? Let’s take a look.

Why use an activity tracker?

One of the most powerful predictors for being active is whether or not you are monitoring how active you are.

Most people have a vague idea of how active they are, but this is inaccurate a lot of the time. Once people consciously start to keep track of how much activity they do, they often realise it’s less than what they thought, and this motivates them to be more active.

You can self-monitor without an activity tracker (just by writing down what you do), but this method is hard to keep up in the long run and it’s also a lot less accurate compared to devices that track your every move 24/7.

By tracking steps or “activity minutes” you can ascertain whether or not you are meeting the physical activity guidelines (150 minutes of moderate to vigorous physical activity per week).

It also allows you to track how you’re progressing with any personal activity goals, and view your progress over time. All this would be difficult without an activity tracker.

Research has shown the most popular brands of activity trackers are generally reliable when it comes to tracking basic measures such as steps and activity minutes.

But wait, there’s more

Many activity trackers on the market nowadays track a range of other measures which their manufacturers promote as important in monitoring health and fitness. But is this really the case? Let’s look at some of these.

Resting heart rate

This is your heart rate at rest, which is normally somewhere between 60 and 100 beats per minute. Your resting heart rate will gradually go down as you become fitter, especially if you’re doing a lot of high-intensity exercise. Your risk of dying of any cause (all-cause mortality) is much lower when you have a low resting heart rate.

So, it is useful to keep an eye on your resting heart rate. Activity trackers are pretty good at tracking it, but you can also easily measure your heart rate by monitoring your pulse and using a stopwatch.

Heart rate during exercise

Activity trackers will also measure your heart rate when you’re active. To improve fitness efficiently, professional athletes focus on having their heart rate in certain “zones” when they’re exercising – so knowing their heart rate during exercise is important.

But if you just want to be more active and healthier, without a specific training goal in mind, you can exercise at a level that feels good to you and not worry about your heart rate during activity. The most important thing is that you’re being active.

Also, a dedicated heart rate monitor with a strap around your chest will do a much better job at measuring your actual heart rate compared to an activity tracker worn around your wrist.

Maximal heart rate

This is the hardest your heart could beat when you’re active, not something you could sustain very long. Your maximal heart rate is not influenced by how much exercise you do, or your fitness level.

Most activity trackers don’t measure it accurately anyway, so you might as well forget about this one.

VO₂max

Your muscles need oxygen to work. The more oxygen your body can process, the harder you can work, and therefore the fitter you are.

VO₂max is the volume (V) of oxygen (O₂) we could breathe maximally (max) over a one minute interval, expressed as millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). Inactive women and men would have a VO₂max lower than 30 and 40 ml/kg/min, respectively. A reasonably good VO₂max would be mid thirties and higher for women and mid forties and higher for men.

VO₂max is another measure of fitness that correlates well with all-cause mortality: the higher it is, the lower your risk of dying.

For athletes, VO₂max is usually measured in a lab on a treadmill while wearing a mask that measures oxygen consumption. Activity trackers instead look at your running speed (using a GPS chip) and your heart rate and compare these measures to values from other people.

If you can run fast with a low heart rate your tracker will assume you are relatively fit, resulting in a higher VO₂max. These estimates are not very accurate as they are based on lots of assumptions. However, the error of the measurement is reasonably consistent. This means if your VO₂max is gradually increasing, you are likely to be getting fitter.

So what’s the take-home message? Focus on how many steps you take every day or the number of activity minutes you achieve. Even a basic activity tracker will measure these factors relatively accurately. There is no real need to track other measures and pay more for an activity tracker that records them, unless you are getting really serious about exercise.

Corneel Vandelanotte, Professorial Research Fellow: Physical Activity and Health, CQUniversity Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.