Made from fermented apples and naturally high in acetic acid, apple cider vinegar has been popular in recent years for its purported health benefits – from antibacterial properties to antioxidant effects and potential for helping manage blood sugars.

Its origins as a health tonic stretch much further back. Hippocrates used it to treat wounds, fever and skin sores.

An experimental study, released today, looks into whether apple cider vinegar could be effective for weight loss, reduce blood glucose levels and reduce blood lipids (cholesterol and triglycerides).

The results suggest it could reduce all three – but it might not be as simple as downing an apple cider vinegar drink a day.

What did they do?

A group of scientists in Lebanon did a double-blinded, randomised, clinical trial in a group of overweight and obese young people aged from 12–25 years.

Researchers randomly placed 30 participants in one of four groups. The participants were instructed to consume either 5, 10 or 15ml of apple cider vinegar diluted into 250ml of water each morning before they ate anything for 12 weeks. A control group consumed an inactive drink (a placebo) made (from lactic acid added to water) to look and taste the same.

Typically this sort of study provides high quality evidence as it can show cause and effect – that is the intervention (apple cider vinegar in this case) leads to a certain outcome. The study was also double-blinded, which means neither the participants or the scientists involved with collecting the data knew who was in which group.

So, what did they find?

After a period of three months apple cider vinegar consumption was linked with significant falls in body weight and body mass index (BMI). On average, those who drank apple cider vinegar during that period lost 6–8kg in weight and reduced their BMI by 2.7–3 points, depending on the dose. They also showed significant decreases in the waist and hip circumference.

The authors also report significant decreases in levels of blood glucose, triglycerides, and cholesterol in the apple cider groups. This finding echoes previous studies. The placebo group, who were given water with lactic acid, had much smaller decreases in weight and BMI. There were also no significant decreases in blood glucose and blood lipids.

From animal studies, it is thought the acetic acid in apple cider vinegar may affect the expression of genes involved in burning fats for energy. The new study did not explore whether this mechanism was involved in any weight loss.

Is this good news?

While the study appears promising, there are also reasons for caution.

Firstly, study participants were aged from 12 to 25, so we can’t say whether the results could apply to everyone.

The statistical methods used in the study don’t allow us to confidently say the same amount of weight loss would occur again if the study was done again.

And while the researchers kept records of the participants’ diet and exercise during the study, these were not published in the paper. This makes it difficult to determine if diet or exercise may have had an impact. We don’t know whether participants changed the amount they ate or the types of food they ate, or whether they changed their exercise levels.

The study used a placebo which they tried to make identical in appearance and taste to the active treatment. But people may still be able to determine differences. Researchers may ask participants at the end of a study to guess which group they were in to test the integrity of the placebo. Unfortunately this was not done in this study, so we can’t be certain if the participants knew or not.

Finally, the authors do not report whether anyone dropped out of the study. This could be important and influence results if people who did not lose weight quit due to lack of motivation.

Any other concerns?

Apple cider vinegar is acidic and there are concerns it may erode tooth enamel. This can be a problem with any acidic beverages, including fizzy drinks, lemon water and orange juice.

To minimise the risk of acid erosion some dentists recommend the following after drinking acidic drinks:

• rinsing out your mouth with tap water afterwards
• chewing sugar-free gum afterwards to stimulate saliva production
• avoiding brushing your teeth immediately after drinking because it might damage the teeth’s softened top layer
• drink with a straw to minimise contact with the teeth.

Down the hatch?

This study provides us with some evidence of a link between apple cider vinegar and weight loss. But before health professionals can recommend this as a weight loss strategy we need bigger and better conducted studies across a wider age range.

Such research would need to be done alongside a controlled background diet and exercise across all the participants. This would provide more robust evidence that apple cider vinegar could be a useful aid for weight loss.

Still, if you don’t mind the taste of apple cider vinegar then you could try drinking some for weight loss, alongside a healthy balanced and varied dietary intake. This study does not suggest people can eat whatever they like and drink apple cider vinegar as a way to control weight.

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.

We’re living longer than in previous generations, with one in eight elderly Australians now aged over 85. But the current gap between life expectancy (“lifespan”) and health-adjusted life expectancy (“healthspan”) is about ten years. This means many of us live with significant health problems in our later years.

To increase our healthspan, we need planned, structured and regular physical activity (or exercise). The World Health Organization recommends 150–300 minutes of moderate-intensity exercise – such as brisk walking, cycling and swimming – per week and muscle strengthening twice a week.

Yet few of us meet these recommendations. Only 10% meet the strength-training recommendations. Lack of time is one of the most common reasons.

Walking is cost-effective, doesn’t require any special equipment or training, and can be done with small pockets of time. Our preliminary research, published this week, shows there are ways to incorporate strength-training components into walking to improve your muscle strength and balance.

Why walking isn’t usually enough

Regular walking does not appear to work as muscle-strengthening exercise.

In contrast, exercises consisting of “eccentric” or muscle-lengthening contractions improve muscle strength, prevent muscle wasting and improve other functions such as balance and flexibility.

Typical eccentric contractions are seen, for example, when we sit on a chair slowly. The front thigh muscles lengthen with force generation.

Our research

Our previous research found body-weight-based eccentric exercise training, such as sitting down on a chair slowly, improved lower limb muscle strength and balance in healthy older adults.

We also showed walking down stairs, with the front thigh muscles undergoing eccentric contractions, increased leg muscle strength and balance in older women more than walking up stairs. When climbing stairs, the front thigh muscles undergo “concentric” contractions, with the muscles shortening.

It can be difficult to find stairs or slopes suitable for eccentric exercises. But if they could be incorporated into daily walking, lower limb muscle strength and balance function could be improved.

This is where the idea of “eccentric walking” comes into play. This means inserting lunges in conventional walking, in addition to downstairs and downhill walking.

In our new research, published in the European Journal of Applied Physiology, we investigated the effects of eccentric walking on lower limb muscle strength and balance in 11 regular walkers aged 54 to 88 years.

The intervention period was 12 weeks. It consisted of four weeks of normal walking followed by eight weeks of eccentric walking.

The number of eccentric steps in the eccentric walking period gradually increased over eight weeks from 100 to 1,000 steps (including lunges, downhill and downstairs steps). Participants took a total of 3,900 eccentric steps over the eight-week eccentric walking period while the total number of steps was the same as the previous four weeks.

We measured the thickness of the participants’ front thigh muscles, muscle strength in their knee, their balance and endurance, including how many times they could go from a sitting position to standing in 30 seconds without using their arms. We took these measurements before the study started, at four weeks, after the conventional walking period, and at four and eight weeks into the eccentric walking period.

We also tested their cognitive function using a digit symbol-substitution test at the same time points of other tests. And we asked participants to complete a questionnaire relating to their activities of daily living, such as dressing and moving around at home.

Finally, we tested participants’ blood sugar, cholesterol levels and complement component 1q (C1q) concentrations, a potential marker of sarcopenia (muscle wasting with ageing).

What did we find?

We found no significant changes in any of the outcomes in the first four weeks when participants walked conventionally.

From week four to 12, we found significant improvements in muscle strength (19%), chair-stand ability (24%), balance (45%) and a cognitive function test (21%).

Serum C1q concentration decreased by 10% after the eccentric walking intervention, indicating participants’ muscles were effectively stimulated.

The sample size of the study was small, so we need larger and more comprehensive studies to verify our findings and investigate whether eccentric walking is effective for sedentary people, older people, how the different types of eccentric exercise compare and the potential cognitive and mental health benefits.

But, in the meantime, “eccentric walking” appears to be a beneficial exercise that will extend your healthspan. It may look a bit eccentric if we insert lunges while walking on the street, but the more people do it and benefit from it, the less eccentric it will become.

Ken Nosaka, Professor of Exercise and Sports Science, Edith Cowan University

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