How not smoking, avoiding alcohol, exercising cut risk of memory loss by 34%
*Extreme ‘caveman’ diet of fasting every other day may help overweight patients lose 3.6kg in just four weeks
Scientists say avoiding alcohol, cutting out cigarettes and exercising more may protect you from dementia (memory loss).
Researchers have uncovered yet more evidence that having a healthy lifestyle can ward off the memory-robbing disorder.
Their study published in Nature Medicine found having unhealthy habits, such as smoking, raises the risk of dementia by around a third.
But the results gave a ‘less optimistic outlook’ for those at high genetic risk of the disorder, with a healthy lifestyle doing little to protect against it.
Also, research has found alternate day fasting may help overweight patients lose nearly 8lbs in four weeks.
Volunteers were forced to starve for 36 hours before being allowed to indulge in whatever they wanted for 12 hours.
Overall, their calorie intake reduced by more than a third, helping them shed body fat without missing out on the foods they enjoyed. They also had lower levels of chemicals in the body, which have been linked to age-related diseases or inflammation.
Scientists believe it is an easier way to lose weight than counting calories because some find it less restrictive – and they claim it helps because it is similar to the diet of cavemen, when food wasn’t available all the time.
The paper was published in the journal Cell Metabolism
Thomas Pieber, of the Medical University of Graz and co-author, said: “Why exactly calorie restriction and fasting induce so many beneficial effects is not fully clear yet. The elegant thing about strict ADF is that it doesn’t require participants to count their meals and calories: they just don’t eat anything for one day.”
Meanwhile, the study by Dutch academics, published in Nature Medicine, followed hundreds of people for an average of 14 years.
During the course of the Erasmus MC – University Medical Center Rotterdam research, 915 volunteers were struck down with dementia.
The researchers worked out each participant’s genetic risk of dementia by looking for 27 genes heavily linked to the disease.
Volunteers were grouped into either high, intermediate or low risk brackets, depending on which APOE variants they carried. The gene is thought to be linked to around 50 per cent of cases of Alzheimer’s – the most common form of dementia.
All of the participants were then separated into three different groups based on how healthy their lifestyle was considered to be. They were asked about whether they smoked, had depression or diabetes, were physically active, had a healthy diet and avoided social isolation.
Up to a third of all cases are considered to be potentially preventable because they are linked to diet, inactivity or a poor brain health.
Participants who admitted to two or less of the unhealthy habits were considered to have a ‘favourable’ lifestyle. In comparison, those who said they had five were coined to have an ‘unfavourable’ lifestyle. There was also an intermediate group.
Results showed participants with an ‘unfavourable’ lifestyle had a 32 per cent higher risk of dementia than those with a healthier one. The odds remained similar – 29 per cent – after the researchers took into account parental history of the disease and cardiovascular risk factors.
The findings also showed a healthy lifestyle protected people at low or intermediate risk of dementia far more than those considered at high risk.
For example, participants who had a low chance of getting the disease had a 2.5-fold higher risk of dementia if they had an unfavourable lifestyle.
Results showed the same risk was 39 per cent higher among volunteers at intermediate risk – but only five per cent greater in high-risk participants. The team said further trials are needed to confirm the results, and said the study did not take into account how lifestyles change over time or prove a causal link.
It comes after the World Health Organisation said in May that people should exercise more, eat a healthy diet and cut down on alcohol to reduce their risk of dementia.
A huge review of existing evidence found age was the strongest risk factor for the memory-robbing condition – but said it is not an inevitable consequence of ageing.
Although it can’t be cured, people who take good care of themselves may have lower odds of getting it – it is not inevitable, the report said.
Although the quality of evidence to back up many of the WHO’s recommendations was low, most were recommended to improve general health.
Meanwhile, in recent years there has been a surge of research into fasting diets, including intermittent fasting, 5:2 diet and alternate-day fasting (ADF). Advocates claim they have lost weight as well as seen their stress reduce and energy rocket.
In the largest study of its kind to look at the effects of ADF in healthy people, the researchers recruited 60 people.
They were aged between 48 and 52 years and had an average body mass index of 25.5 – which would be considered just within the overweight band by the British National Service (NHS).
For four weeks, one group was told to eat their normal diet – or as much as they wanted – while the other group were on the ADF diet.
The ADF group were monitored to make sure they didn’t consume any calories for 36 hours, before indulging in whatever they fancied for 12 hours.
After four weeks of alternate day fasting, participants had more ketone bodies, even on non-fasting days, which have been shown to promote health in various ways such as protecting the heart.
Ketone bodies, which are molecules produced by the body during fasting, have been found to have anti-aging effects on the vascular system, which could reduce the occurrence of diseases related to blood vessels, such as cardiovascular disease.
Scientists are also researching how ketone bodies may protect against Alzheimer’s.
The participants were found to have reduced levels of sICAM-1. This molecule has been linked to age-associated disease, including cardiovascular disease, and inflammation.
Another reduced hormone was triiodothyronine, which regulates metabolism. Triiodothyronine is a hormone made partly by the thyroid gland and has previously been linked to longevity in humans.
Variations in thyroid function have been linked to an increased risk of cardiovascular disease and death. The participants had reduced amino acids, in particular the amino acid methionine. This has been shown to extend the life of rodents in experiments.
To assess how ADF affects the immune system of people long term, the researchers had included a group of 30 people who had already practiced more than six months of strict ADF before the study.
Even after half a year, participants’ markers of immune function – such as white blood cells, monocytes and B cells – were stable. They were also asked to fill in diaries documenting their fasting days.
Prof. Harald Sourij, co-author, said: “We found on average, during the 12 hours when they could eat normally, the participants in the ADF group compensated for some of the calories lost from the fasting, but not all.”
Overall, participants following the diet consumed 37 per cent less calories and lost an average of 7.7lbs (3.5kg).
The participants also had slightly less belly fat, according to the paper published in the journal Cell Metabolism.
The investigators found several other positive effects not linked to weight. For example, they had lower levels of sICAM-1, a molecule linked to age-associated disease, including cardiovascular disease and inflammation.
The researchers noted that ADF is ‘one of the most extreme diet interventions’, but potentially is more successful than just cutting calories.
However, calorie restrictive diets – where a person keeps within a calorie limit per day – can result in malnutrition, the researchers said.
There is also evidence it can compromise the immune system by reducing white blood cells. ADF does not appear to threaten the immune system this way, supporting previous findings.
Co-author Prof. Frank Madeo said: “The reason might be due to evolutionary biology. Our physiology is familiar with periods of starvation followed by food excesses.
“It might also be that continuous low-calorie intake hinders the induction of the age-protective autophagy program, which is switched on during fasting breaks.”
Despite the findings, the researchers don’t recommend embarking on ADF for long periods until more research is done.
Madeo said: “We feel that it is a good regime for some months for obese people to cut weight, or it might even be a useful clinical intervention in diseases driven by inflammation. We advise people not to fast if they have a viral infection, because the immune system probably requires immediate energy to fight viruses.”
In the future, the researchers plan to study the effects of strict ADF in different groups of people including people with obesity and diabetes.
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