Eating flavonoids protects men against Parkinson’s disease

Men who eat flavonoid-rich foods such as berries, tea, apples and red wine significantly reduce their risk of developing Parkinson’s disease, according to new research by Harvard University and the University of East Anglia (UEA).

Published April 4 in the journal Neurology®, the findings add to the growing body of evidence that regular consumption of some flavonoids can have a marked effect on human health. Recent studies have shown that these compounds can offer protection against a wide range of diseases including heart disease, hypertension, some cancers and dementia.

This latest study is the first study in humans to show that flavonoids can protect neurons against diseases of the brain such as Parkinson’s.

Around 130,000 men and women took part in the research. More than 800 had developed Parkinson’s disease within 20 years of follow-up. After a detailed analysis of their diets and adjusting for age and lifestyle, male participants who ate the most flavonoids were shown to be 40 per cent less likely to develop the disease than those who ate the least. No similar link was found for total flavonoid intake in women.

The research was led by Dr Xiang Gao of Harvard School of Public Health in collaboration with Prof Aedin Cassidy of the Department of Nutrition, Norwich Medical School at UEA.

“These exciting findings provide further confirmation that regular consumption of flavonoids can have potential health benefits,” said Prof Cassidy.

“This is the first study in humans to look at the associations between the range of flavonoids in the diet and the risk of developing Parkinson’s disease and our findings suggest that a sub-class of flavonoids called anthocyanins may have neuroprotective effects.”

Prof Gao said: “Interestingly, anthocyanins and berry fruits, which are rich in anthocyanins, seem to be associated with a lower risk of Parkinson’s disease in pooled analyses. Participants who consumed one or more portions of berry fruits each week were around 25 per cent less likely to develop Parkinson’s disease, relative to those who did not eat berry fruits. Given the other potential health effects of berry fruits, such as lowering risk of hypertension as reported in our previous studies, it is good to regularly add these fruits to your diet.”

Flavonoids are a group of naturally occurring, bioactive compunds found in many plant-based foods and drinks. In this study the main protective effect was from higher intake of anthocyanins, which are present in berries and other fruits and vegetables including aubergines, blackcurrants and blackberries. Those who consumed the most anthocyanins had a 24 per cent reduction in risk of developing Parkinson’s disease and strawberries and blueberries were the top two sources in the US diet.

The findings must now be confirmed by other large epidemiological studies and clinical trials.

Parkinson’s disease is a progresssive neurological condition affecting one in 500 people, which equates to 127,000 people in the UK. There are few effective drug therapies available.

Dr Kieran Breen, director of research at Parkinson’s UK said: “This study raises lots of interesting questions about how diet may influence our risk of Parkinson’s and we welcome any new research that could potentially lead to prevention.

“While these new results look interesting there are still a lot of questions to answer and much more research to do before we really know how important diet might be for people with Parkinson’s.”

 

Reference

Gao X, Cassidy A, Schwarzschild MA, Rimm EB, Ascherio A. Habitual intake of dietary flavonoids and risk of Parkinson disease. Neurology, 2012 DOI: 10.1212/WNL.0b013e31824f7fc4

 

An Apple or Pear a Day May Keep Strokes Away

Apples and pears may keep strokes away. That’s the conclusion of a Dutch study published in Stroke: Journal of the American Heart Association in which researchers found that eating a lot of fruits and vegetables with white flesh may protect against stroke.

While previous studies have linked high consumption of fruits and vegetables with lower stroke risk, the researchers’ prospective work is the first to examine associations of fruits and vegetable color groups with stroke.

The color of the edible portion of fruits and vegetables reflects the presence of beneficial phytochemicals such as carotenoids and flavonoids.

Researchers examined the link between fruits and vegetable color group consumption with 10-year stroke incidence in a population-based study of 20,069 adults, with an average age of 41. The participants were free of cardiovascular diseases at the start of the study and completed a 178-item food frequency questionnaire for the previous year.

Fruits and vegetables were classified in four color groups:

  • Green, including dark leafy vegetables, cabbages and lettuces
  • Orange/Yellow, which were mostly citrus fruits
  • Red/Purple, which were mostly red vegetables
  • White, of which 55 percent were apples and pears

 

During 10 years of follow-up, 233 strokes were documented. Green, orange/yellow and red/purple fruits and vegetables weren’t related to stroke. However, the risk of stroke incidence was 52 percent lower for people with a high intake of white fruits and vegetables compared to people with a low intake.

Each 25 gram per day increase in white fruits and vegetable consumption was associated with a 9 percent lower risk of stroke. An average apple is 120 grams.

“To prevent stroke, it may be useful to consume considerable amounts of white fruits and vegetables,” said Linda M. Oude Griep, M.Sc., lead author of the study and a postdoctoral fellow in human nutrition at Wageningen Uninversity in the Netherlands. “For example, eating one apple a day is an easy way to increase white fruits and vegetable intake.

“However, other fruits and vegetable color groups may protect against other chronic diseases. Therefore, it remains of importance to consume a lot of fruits and vegetables.”

Apples and pears are high in dietary fiber and a flavonoid called quercetin. In the study, other foods in the white category were bananas, cauliflower, chicory and cucumber.

Potatoes were classified as a starch.

Previous research on the preventive health benefits of fruits and vegetables focused on the food’s unique nutritional value and characteristics, such as the edible part of the plant, color, botanical family and its ability to provide antioxidants.

U.S. federal dietary guidelines include using color to assign nutritional value. The U.S. Preventive Health Services Taskforce recommends selecting each day vegetables from five subgroups: dark green, red/orange, legume, starchy and other vegetables.

Before the results are adopted into everyday practice, the findings should be confirmed through additional research, Oude Griep said. “It may be too early for physicians to advise patients to change their dietary habits based on these initial findings,” she said.

An accompanying editorial notes that the finding should be interpreted with caution because food frequency questionnaires may not be reliable.

In addition, “the observed reduction in stroke risk might further be due to a generally healthier lifestyle of individuals consuming a diet rich in fruits and vegetables,” writes Heike Wersching, M.D., M.Sc., of Institute of Epidemiology and Social Medicine at the University of Münster, in Germany.

 

Reference 

Griep LM, Verschuren WM, Kromhout D, Ocké MC, Geleijnse JM. Raw and processed fruit and vegetable consumption and 10-year stroke incidence in a population-based cohort study in the Netherlands. Eur J Clin Nutr 2011; 65 (7): 791-9.

 

‘Apple A Day’ Advice Rooted In Science

Everyone has heard the old adage, “an apple a day keeps the doctor away.” We all know we should eat more fruit. But why apples? Do they contain specific benefits?

According to Dr. Bahram H. Arjmandi, PhD, RD, Margaret A. Sitton Professor and Chair, Department of Nutrition, Food and Exercise Sciences at The Florida State University, apples are truly a “miracle fruit” that convey benefits beyond fiber content. Animal studies have shown that apple pectin and polyphenols in apple improve lipid metabolism and lower the production of pro-inflammatory molecules. Arjmandi’s most recent research is the first to evaluate the long-term cardioprotective effects of daily consumption of apple in postmenopausal women. The results of this USDA-funded study was presented at Experimental Biology 2011 in Washington, DC.

This study randomly assigned 160 women ages 45-65 to one of two dietary intervention groups: one received dried apples daily (75g/day for 1 year) and the other group ate dried prunes every day for a year. Blood samples were taken at 3, 6 and 12-months. The results surprised Dr. Arjmandi, who stated that “incredible changes in the apple-eating women happened by 6 months- they experienced a 23% decrease in LDL cholesterol,” which is known as the “bad cholesterol.” The daily apple consumption also led to a lowering of lipid hydroperoxide levels and C-reactive protein in those women.

“I never expected apple consumption to reduce bad cholesterol to this extent while increasing HDL cholesterol or good cholesterol by about 4%,” Arjmandi said. Yet another advantage is that the extra 240 calories per day consumed from the dried apple did not lead to weight gain in the women; in fact, they lost on average 3.3 lbs. “Reducing body weight is an added benefit to daily apple intake” he said. Part of the reason for the weight loss could be the fruit’s pectin, which is known to have a satiety effect. The next step in confirming the results of this study is a multi-investigator nationwide study.

There is frequently some truth behind our common expressions, and in the case of ‘an apple a day,’ Dr. Arjmandi has shown that nutrition science backs up the expression. “Everyone can benefit from consuming apples,” he said.