As if you needed telling - eat more fruit and vegetables and live longer

Two pieces of research out this week have confirmed what your mother always told you - eat your fruit and veg!

Scientists have shown that a diet rich in fruits and vegetables can overcome a genetic predisposition to cardiovascular disease (CVD) in some people.

The Canadian study looked at the interaction between genetics and the environment and their effect on heart health. In particular, the study focused on single nucleotide polymorphisms (SNPs), which are differences in single building blocks of DNA or nucleotides.

Previous studies have shown a link between an increased risk of heart problems, (heart disease, heart attacks, strokes, etc.) and a cluster of these SNPs in a chromosomal region called 9p21. In this new study, the researchers investigated the link between 9p21 and CVD in a range of people of different ethnicities and diets.

Overall, the study looked at over 27,000 people and found that the negative effect of the 9p21 SNP could be mitigated by consuming a diet rich in fruits and vegetables.

Meanwhile, scientists in Oxford have shown that people in Scotland, wales and Northern Ireland would do well to follow their English neighbours and eat more fruit and vegetables. The study says that over the three-year study period 22,000 excess deaths caused by heart disease, stroke and 10 cancers occurred in Scotland, Wales and Northern Ireland compared to England.

The researchers say that consumption of fruit and veg in Northern Ireland is about 20% less than in England. Salt and saturated fat levels are also higher in the parts of the UK outside England.

Changing to an 'English' diet - although it's far from perfect, say the authors of the report, could save about 4,000 lives a year in the rest of the UK.

References:
Do et al., The Effect of Chromosome 9p21 Variants on Cardiovascular Disease May Be Modified by Dietary Intake: Evidence from a Case/Control and a Prospective Study. PLOS Medicine 9(10): e1001106. doi:10.1371/journal.pmed.1001106 LINK


Scarborough P, Morgan RD, Webster P, et al. Differences in coronary heart disease, stroke and cancer mortality rates between England, Wales, Scotland and Northern Ireland: the role of diet and nutrition. BMJ Open 2011;1:e000263. doi: 10.1136/bmjopen- 2011-000263 LINK

Potato Could Reduce Blood Pressure

Scientists report that just a couple servings of spuds a day reduces blood pressure almost as much as oatmeal without causing weight gain. Scientists reported on the research, done on a group of overweight people with high blood pressure, at the National Meeting & Exposition of the American Chemical Society (ACS), in Denver, Colorado this week.

The bad news is that the research was not done with chips or fries, but with potatoes cooked without oil in a microwave oven. Although researchers used purple potatoes, they believe that red-skin potatoes and white potatoes may have similar effects.

"The potato, more than perhaps any other vegetable, has an undeserved bad reputation that has led many health-conscious people to ban them from their diet," said Joe Vinson, who headed the research. "Mention 'potato' and people think 'fattening, high-carbs, empty calories'. In reality, when prepared without frying and served without butter, margarine or sour cream, one potato has only 110 calories and dozens of healthful phytochemicals and vitamins. We hope our research helps to remake the potato's popular nutritional image."

In the new study, 18 patients who were primarily overweight/obese with high blood pressure ate 6-8 purple potatoes (each about the size of a golf ball) with skins twice daily for a month. They used purple potatoes because the pigment, or coloring material, in fruits and vegetables is especially rich in beneficial phytochemicals including phenolic acids, anthocyanins and carotenoids. Scientists monitored the patients' blood pressure, both systolic (the higher number in a blood pressure reading like 120/80) and diastolic. The average diastolic blood pressure dropped by 4.3 percent and the systolic pressure decreased by 3.5 percent, said Vinson, who is with the University of Scranton in Pennsylvania and has done extensive research on healthful components in foods. The majority of subjects took anti-hypertensive drugs and still had a reduction in blood pressure. None of the study participants gained weight.

Vinson said that other studies have identified substances in potatoes with effects in the body similar to those of the well-known ACE-inhibitor medications, a mainstay for treating high blood pressure. Other phytochemicals in potatoes occur in amounts that rival broccoli, spinach and Brussels sprouts, and also may be involved, Vinson added.

high cooking temperatures seem to destroy most of the healthy substances in a potato Unfortunately for French fry and potato chip fans, those high cooking temperatures seem to destroy most of the healthy substances in a potato, leaving mainly starch, fat and minerals. Potatoes in the study were simply microwaved, which Vinson said seems to be the best way to preserve nutrients.

The purple potatoes used in the study are becoming more widely available in supermarkets and especially in specialty food stores and farmers' markets. Vinson said that he strongly suspects a future study using white potatoes, now in the planning stages, will produce similar results.

Chocolate & the Heart

I've currently got a large box of milk chocolates in my office. I'm being very good and limiting myself to a few every day. I know they aren't much good for me, but they are very tasty!

To attempt to use the recent chocolate research that says it is good for your heart as an excuse to eat the whole box here and now is missing the point completely.

The results of a 'meta-analysis' - i.e. combining the results of a number of studies, in this case seven, allowed the researchers to look at the chocolate consumption of 114,009 individuals along with their overall health. In this case, they looked at heart disease, diabetes and strokes.

The results show a 37% decrease in the incidence of cardiovascular disease in people who eat a high level of chocolate compared to people who eat a low level of the stuff. Although the work does not go into why this would be the case the authors note that this association may be due to "the high content of polyphenols present in cocoa products".

The authors are quick to caution against deciding that chocolate is the way forward for a healthy diet noting that commercially available chocolate is chock full of calories meaning that weight gain, hypertension and diabetes may be the side effects.

They suggest that we might look at the high levels of sugar and fat in commercially available chocolate and reduce it. This would allow us to be exposed to the beneficial effects of 'pure' chocolate, without too much of the nasty fats and sugars.

This is backed up by the British Heart Foundation. Their Senior Dietitian Victoria Taylor warned that "We can’t start advising people to eat lots of chocolate based on this research. It didn’t explore what it is about chocolate that could help and if one particular type of chocolate is better than another.

"there are much better places to start than at the bottom of a box of chocolates" - British Heart Foundation “If you want to reduce your heart disease risk, there are much better places to start than at the bottom of a box of chocolates. You can still eat chocolate as part of a balanced diet but moderation is key because this sweet treat is usually packed with saturated fat and calories.”

The authors noted that the studies they looked at in their meta-analysis didn't allow them to look at the differences between 'good' and 'bad; chocolate and the association with heart problems.

There are also problems with the use of such observational studies. As the authors themselves note: "Chocolate intake is likely to be underestimated by consumers". Now, where was that box of chocs?

The research is Open-Access and free to view by all here.

Sleep, Diet and Life Expectancy

Sleep seems to be on the mind of lots of scientists over the last few days with a number of intriguing sets of results being published.

According to a study published on Tuesday in PLoS Biology, when flies are starved they are able to stay awake for long periods of time without feeling the downsides of going without a nap.

The experiment was conducted by starving some flies while allowing others to feed normally and then providing a physical jolt to prevent them from nodding off. The starved flies were less susceptible to the effects of sleep deprivation such as cognitive impairment.

The scientists also made use of mutant fruit flies which lack the 'canonical clock gene cycle'. Such flies normally die within 10 hours of being deprived of sleep, but when starved they lasted nearly three times as long.

The authors believe that two genes recently shown to control the response to starvation in fruit flies brummer (bmm) and Lipid storage droplet 2 (Lsd2) also have a role to play in sleep regulation.

"brummer mutants, which are fat, show exaggerated response to sleep loss. In contrast, mutants for Lipid storage droplet 2 are lean and are able to stay awake without becoming sleepy or showing signs of cognitive impairment" the authors write.

"Given that metabolic pathways are highly conserved between mammals and flies, it will be interesting to determine whether lipid [fat] metabolism also plays a similar role in mammals".

Meanwhile, a recent study reported in the September 1st issue of Sleep found that men with serious sleep problems had much higher mortality rates.

The study of 1,742 men and women, who were randomly sampled in Pennsylvania and studied for 14 and 10 years respectively found that the overall mortality rate was 21% for men and 5% for women.

'in men who experienced insomnia, that mortality rate was significantly increased' However, in men who experienced insomnia (who slept for less than 6 hours a night), that mortality rate was significantly increased. In women, on the other hand, mortality was not found to be associated with insomnia and disrupted sleep.

Of the men who were studied, 51% of insomniacs died during the study period, compared to just 9% of normal sleepers.

“Insomnia has potentially very severe side effects,” said study co-author  Edward Bixler. “It needs to be treated, and more effort needs to be put into sorting out better treatments.”

More evidence of sleepless nights being bad for your health came from a report also published on Wednesday (Sept. 1st) in which US researchers found that teenagers who sleep for less than 8 hours a night during Monday to Friday eat more snacks and fatty foods then those who get a solid eight hours.

The study analysed 240 teenagers and asked them to wear wrist monitors that measured sleep duration. During the study period, researchers discussed eating habits with the participants twice a day to monitor their food intake.

'teens who did not sleep well consumed 2.2% more calories from fat' The results, also published in the September issue of Sleep, showed that teens who did not sleep well consumed 2.2% more calories from fat compared to those who slept for eight hours. Girls were more prone to this than boys; consuming 3.3.% more calories from fat compared to 0.9% in boys.

Teenagers who slept for eight hours or more a day during the working week consumed 1,723 calories per day, with 1,968 calories being consumed by those who  slept for less than eight hours.

The authors of this study have suggested that sleep may be the "missing link" in the fight against obesity, which up to now has focused on diet and exercise.

From this handful of recent studies it seems that diet and sleep are certainly closely linked and that more research is required to find out exactly the nature of that link.

One thing is for sure, if the results of the the mortality study is anything to go by, the outcome of cutting back on sleep time (either by choice or not) can be serious effects on your health and life expectancy.

References:
Thimgan MS, Suzuki Y, Seugnet L, Gottschalk L, & Shaw PJ (2010). The perilipin homologue, lipid storage droplet 2, regulates sleep homeostasis and prevents learning impairments following sleep loss. PLoS biology, 8 (8) PMID: 20824166


Vgontzas AN; Liao D; Pejovic S; Calhoun S; Karataraki M; Basta M; Fernández-Mendoza J; Bixler EO (2010). Insomnia with short sleep duration and mortality: the Penn State Cohort SLEEP, 33 (9), 1159-1164


Weiss A; Xu F; Storfer-Isser A; Thomas A; Ievers-Landis CE; Redline S (2010). The association of sleep duration with adolescents’ fat and carbohydrate consumption SLEEP, 33 (9), 1201-1209