Latest Research News
- Long-known to lower LDL cholesteral, a new study shows oats also impact other markers that may be better measures of cardiovascular risk for those with diabetes or metabolic syndrome.
- An experimental study shows that whole grain foods significantly lower blood pressure compared to eating the equivalent refined grain foods.
- A review of population studies shows that the more whole grains you eat, the lower your risk of cardiovascular disease.
Eating oats lowers cholesterol on 3 markers
It’s long been known that eating oats can lower cholesterol levels, but the research focus has been on the effect on LDL cholesterol. However, there is growing evidence that two other markers provide an even more accurate assessment of cardiovascular risk:
- non-HDL cholesterol (total cholesterol minus HDL cholesterol)
- apolipoprotein B (apoB) — a lipoprotein that carries LDL cholesterol through the blood.
This is especially true for people with metabolic syndrome and Type 2 diabetes, since they typically don't have elevated LDL cholesterol levels.
In light of this, it’s good to see a review and meta-analysis of 58 clinical trials has concluded that eating oat fibre can reduce all three markers.
The reason is thought to lie in beta-glucan, a viscous soluble fibre, for which oats are a rich source. Oat bran contains twice as much as oat meal.
The review found that overall, LDL cholesterol was reduced by 4.2%, non-HDL cholesterol by 4.8% and apoB by 2.3%.
Whole grain diet reduces cardiovascular disease risk
A study involving 33 overweight and obese adults who followed a whole grain diet for eight weeks and a refined grain diet during another eight week period, found that those on the whole grain diet saw a more than three-fold improvement in diastolic blood pressure compared to the refined grain diet.
This improvement equates to reducing the risk of death from heart disease by almost one-third, and the risk of death from a stroke by two-fifths.
Participants were under 50. Before age 50, an elevated diastolic blood pressure is associated with increased cardiovascular disease risk (diastolic is the bottom number, when you’re given a blood pressure reading).
Overall, there were substantial reductions in body weight, fat loss, systolic blood pressure, total cholesterol, and LDL cholesterol during both diet periods, but these differences were due to the people changing their normal dietary habits to carefully controlled diets. The order of diets was randomized, and there was a ten week period between them. The 33 participants included 6 men and 27 women.
The finding is supported by a meta-analysis of 45 different population studies that investigated whole grain intake in relation to risk of future illness or death due to specific causes. The review found that eating three more portions of whole grain foods a day was associated with a lower risk for all cardiovascular diseases and for dying of cancer, diabetes, and respiratory and infectious diseases. Three servings would be, say, two slices of whole-grain bread and one bowl of whole-grain cereal.
The benefits were dose-dependent, with the lowest risk found among those with the highest intake of whole-grain products: 7 to 7 ½ servings of whole grain products a day. This corresponds to 210-225 grams of whole grain products in fresh weight and about 70-75 grams of whole grains in dry weight.
Ho, H., Sievenpiper, J., Zurbau, A., Blanco Mejia, S., Jovanovski, E., Au-Yeung, F., . . . Vuksan, V. (2016). The effect of oat β-glucan on LDL-cholesterol, non-HDL-cholesterol and apoB for CVD risk reduction: A systematic review and meta-analysis of randomised-controlled trials. British Journal of Nutrition, 116(8), 1369-1382. doi:10.1017/S000711451600341X
Kirwan, J. P., Malin, S. K., Scelsi, A. R., Kullman, E. L., Navaneethan, S. D., Pagadala, M. R., … Ross, A. B. (2016). A Whole-Grain Diet Reduces Cardiovascular Risk Factors in Overweight and Obese Adults: A Randomized Controlled Trial. The Journal of Nutrition, 146(11), 2244–2251. https://doi.org/10.3945/jn.116.230508
Aune Dagfinn, Keum NaNa, Giovannucci Edward, Fadnes Lars T, Boffetta Paolo, Greenwood Darren C et al. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies BMJ 2016; 353 :i2716 http://www.bmj.com/content/353/bmj.i2716
A large, long-running European study, involving 3,428 male patients aged 45-74 years, has found that depression is a major risk factor for cardiovascular disease. The risk is almost as great as that due to high cholesterol levels or obesity.
Ladwig, KH. et al. (2016): Room for depressed and exhausted mood as a risk predictor for all-cause and cardiovascular mortality beyond the contribution of the classical somatic risk factors in men. Atherosclerosis, doi: 10.1016/j.atherosclerosis.2016.12.003
A meta-analysis of 40 epidemiological studies from 1999 to 2016 has concluded that that people in the highest category of dietary magnesium consumption had a 10% lower risk of coronary heart disease, 12% lower risk of stroke and a 26% lower risk of type-2 diabetes compared to those in the lowest category. A dose–response analysis revealed that a 100 mg/day increase in dietary magnesium intake is significantly associated with a 7%, 22%, and 19% decrease in the risk of stroke, heart failure, and type 2 diabetes, respectively.
Magnesium-rich foods include spices, nuts, beans, cocoa, whole grains and green leafy vegetables.
Magnesium deficiency is relatively common, estimated to affect between 2.5% and 15% of the population. The recommended dietary allowance of magnesium is 350mg/day for an average male adult and 300mg/day for an average adult female, with an additional 150mg/day during pregnancy and lactation
Fudi Wang et al. 2016. Dietary magnesium intake and risk of cardiovascular disease, type 2 diabetes, and allcause mortality: A dose-response meta-analysis of prospective cohort studies. BMC Medicine, DOI: 10.1186/s12916-016-0742-z
A review and meta-analysis of studies from 1982 to 2015, evaluating relationships between egg intake and coronary heart disease (total of 276,000 subjects) and stroke (total of 308,000 subjects) has found that consumption of up to one egg per day had no association with coronary heart disease (CHD) and a 12% reduction of stroke risk.
The study follows on from a 2015 meta-analysis in which dietary cholesterol was shown to have no association with cardiovascular diseases, including coronary artery disease and stroke. Consistent with this, the 2015 Dietary Guidelines for Americans placed no daily limit on dietary cholesterol and noted eggs are an affordable, accessible, nutrient-rich source of high quality protein.
Alexander, D. D., Miller, P. E., Vargas, A. J., Weed, D. L., & Cohen, S. S. (2016). Meta-analysis of Egg Consumption and Risk of Coronary Heart Disease and Stroke. Journal of the American College of Nutrition, 35(8), 704–716. https://doi.org/10.1080/07315724.2016.1152928
A study involving 1,818 Hispanic Americans has confirmed that diabetes, whether controlled or not, is linked to worse measures of cardiac structure and function, and also shows that this happens very early in the development of diabetes.
Demmer, R. T., Allison, M. A., Cai, J., Kaplan, R. C., Desai, A. A., Hurwitz, B. E., … Rodriguez, C. J. (2016). Association of Impaired Glucose Regulation and Insulin Resistance With Cardiac Structure and Function. Circulation: Cardiovascular Imaging, 9(10), e005032. https://doi.org/10.1161/CIRCIMAGING.116.005032
For two years, 70 obese postmenopausal women with normal fasting plasma glucose levels ate either a Paleolithic-type diet or a “prudent” diet. The Paleolithic-type diet was based on lean meat, fish, eggs, vegetables, fruits, nuts and berries, with rapeseed, olive oils and avocado as additional fat sources. The diet excluded dairy products, cereals, added salt and refined fats and sugar. 30% of the calories were supposed to come from protein, 30% from carbohydrates, and 40% from fats with high unsaturated fatty acid content. The prudent control diet had a markedly different target: 15% in protein, 30% in fat, and 55% in carbohydrates.
Both groups took part in 12 group sessions led by a dietitian, and kept ongoing records of their food intake.
Both groups lost significant body weight and had significantly less abdominal obesity, but the women eating the Paleolithic-type diet also had significantly lower levels of specific fatty acids associated with insulin resistance, compared with those on the prudent control diet. Presumably this reflects the marked change in the types of fats eaten. At the end of the two years, the women eating the Paleolithic-type diet reported that their intake of saturated fatty acids decreased by 19%, while monounsaturated fatty acids increased by 47% and polyunsaturated fatty acids by 71%.
A Finnish study involving 2,189 healthy men aged 42-60 found that over 19 years, 417 men (19%) were diagnosed with type 2 diabetes. Those with high omega-6 polyunsaturated fatty acid concentrations in their blood were 46% less likely to develop diabetes. When analyzed, it turned out that this association depended on linoleic and arachidonic acid concentrations only; high serum gamma-linolenic and dihomo-γ-linolenic acid concentrations were linked to a higher risk.
The serum linoleic acid concentration is determined by the person's diet, and the main sources of linoleic acid are vegetable oils, nuts and seeds. Arachidonic acid is present in meat and eggs; however, the human body can also make arachidonic acid from linoleic acid.
Gamma-linolenic acid and dihomo-γ-linolenic acid are mainly formed in the human body from linoleic acid, but their concentrations in serum are very low.
Linoleic acid is the most common omega-6 fatty acid, and has been linked to a reduced risk of cardiovascular diseases as well as type 2 diabetes.
Teymoor Yary, Sari Voutilainen, Tomi-Pekka Tuomainen, Anu Ruusunen, Tarja Nurmi, Jyrki K Virtanen 2016. Serum n-6 polyunsaturated fatty acids, delta-5- and delta-6-desaturase activities and risk of incident type 2 diabetes in men: The Kuopio Ischaemic Heart Disease Risk Factor Study. American Journal of Clinical Nutrition, Published online March 24, 2016 http://ajcn.nutrition.org/content/early/2016/03/23/ajcn.115.128629.abstract
A large study comparing the experiences of more than 10,000 patients with suspected coronary heart diseases has found that
- women have more risk factors for heart disease than men but are typically assessed to have lower risk
- women were older (62.4 vs 59), more likely to be hypertensive (66.6% vs 63.2%), and more likely to have a family history of early heart disease (34.6% vs 29.3%); they were less likely to smoke (45.6% vs 57%)
- women were more likely to be referred for imaging stress tests compared to men, but were less likely to have a positive test (9.7% vs 15%)
- chest pain was an equally common symptom (73% of women and 72% of men complained of this when presenting), but men were more likely to characterize their chest pain as a dull ache or a burning sensation, while women most often described it as crushing/pressure/squeezing/tightness.
- women were more likely than men to have back, neck, or jaw pain, and palpitations as the primary presenting symptoms
- men were more likely to have fatigue and weakness, although this was still unusual as the primary complaint.
Hemal K, Pagidipati NJ, Coles A, et al. Sex Differences in Demographics, Risk Factors, Presentation, and Noninvasive Testing in Stable Outpatients With Suspected Coronary Artery Disease: Insights From the PROMISE Trial. J Am Coll Cardiol Img. 2016;9(4):337-346. doi:10.1016/j.jcmg.2016.02.001.
Depression is a known risk factor for cardiovascular disease, but a large study suggests that effectively and promptly treating depression can reduce a patient's heart risks to the same level as those who never had short-term depression.
The study involved 7,550 patients who completed at least two depression questionnaires over the course of one to two years.
The study was presented at the 2016 American College of Cardiology Scientific Sessions.
A 10-year French study of 7,313 older adults (65+), of whom nearly 30% of the women and 15% of the men had high levels of depressive symptoms, has found that repeated occurrences of depression produced increasing risk of heart disease or stroke. Those who had high levels of depressive symptoms on one, two, three, or four occasions during the study had 15%, 32%, 52%, and 75% greater risk, respectively, of experiencing heart disease or stroke events.
Péquignot, R., Dufouil, C., Prugger, C., Pérès, K., Artero, S., Tzourio, C., & Empana, J.-P. (2016). High Level of Depressive Symptoms at Repeated Study Visits and Risk of Coronary Heart Disease and Stroke over 10 Years in Older Adults: The Three-City Study. Journal of the American Geriatrics Society, 64(1), 118–125. http://doi.org/10.1111/jgs.13872
A review of recent neutral studies questioning the benefits of omega-3s for heart health suggests that the findings may have been due to a number of design issues, rather than a lack of substantiated clinical benefits in cardiovascular disease. The issues include such things as:
- aggressive cardiovascular drug treatment overshadowing the benefits of long-chain omega-3s
- high background long-chain omega-3 intake at study initiation
- too few subjects in the study
- treatment duration too short
- insufficient LC omega-3 dosage
- increase in omega-6 fatty acid intake during the study
- failure to assess the LC omega-3 status of the subjects prior to and during treatment
- lack of clarity concerning which mechanisms were expected to produce benefits
The existing body of gold-standard research showing omega-3s may reduce cardiovascular death risk, maintain healthy blood pressure and improve triglyceride levels also makes it difficult to conclude that EPA and DHA consumption does not contribute to a healthy heart.
Rice, H. B., Bernasconi, A., Maki, K. C., Harris, W. S., von Schacky, C., & Calder, P. C. (2016). Conducting omega-3 clinical trials with cardiovascular outcomes: Proceedings of a workshop held at ISSFAL 2014. Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA), 107, 30–42. http://doi.org/10.1016/j.plefa.2016.01.003
A study has revealed that the immune system has a seasonal cycle, in which its activity is boosted during the winter and relaxes during the summer. While the winter increase in immune defences presumably helps us stave off infections, it also raises the risk of harmful inflammation, effectively lowering the threshold for heart attacks, stroke, diabetes and even some psychiatric conditions. This may explain why deaths from conditions ranging from heart attacks to diabetes and schizophrenia increase in winter.
The study used blood samples from more than 16,000 people living in both the northern and southern hemisphere
Dopico, X. C., Evangelou, M., Ferreira, R. C., Guo, H., Pekalski, M. L., Smyth, D. J., … Todd, J. A. (2015). Widespread seasonal gene expression reveals annual differences in human immunity and physiology. Nature Communications, 6, 7000. http://doi.org/10.1038/ncomms8000
Anecdotal and scientific evidence suggests curcumin, a compound found in turmeric, promotes health because it lowers inflammation. However, it is not absorbed well by the body. Most curcumin in food or supplements stays in the gastrointestinal tract, and any portion that's absorbed is metabolized quickly.
A new study thinks they've come up with a better and more effective way to deliver curcumin, and in so doing has demonstrated how it works. Curcumin powder was mixed with castor oil and polyethylene glycol, allowing it to dissolve and be more easily absorbed by the gut to enter the bloodstream and tissues.
When this was given to mice who had been injected with an extract that stimulates an immune reaction, a key protein that triggers an immune response was blocked. The mice given plain curcumin, on the other hand, showed the same protein actively triggering an immune response.
The emulsified curcumin also stopped recruitment of macrophages. Inflammation triggered by overactive macrophages has been linked to cardiovascular disease, disorders that accompany obesity, Crohn's disease, rheumatoid arthritis, inflammatory bowel disease, diabetes and lupus-related nephritis.
Telomeres are the protective caps at the ends of chromosomes that affect how quickly cells age. With age, they shorten, and as their structural integrity weakens, the cells age and die quicker. Telomere length thus is a biomarker of cellular age. Stress is also thought to shorten telomere length.
A year-long study that looked at the effects of three healthy behaviors in 239 post-menopausal, non-smoking women has found that women who engaged in lower levels of healthy behaviors showed a significantly greater telomere shortening for every major life stressor that occurred. However, stress didn't lead to greater shortening in those women who maintained active lifestyles, healthy diets, and good quality sleep.
Shorter telomeres have become associated with a broad range of aging-related diseases, including stroke, vascular dementia, cardiovascular disease, obesity, osteoporosis diabetes, and many forms of cancer.
Puterman, E., Lin, J., Krauss, J., Blackburn, E. H., & Epel, E. S. (2015). Determinants of telomere attrition over 1 year in healthy older women: stress and health behaviors matter. Molecular Psychiatry, 20(4), 529–535. http://doi.org/10.1038/mp.2014.70
A small study involving 11 non-obese, healthy men aged 20-35, has found that blood flow in leg arteries is significantly impaired after three hours of sitting, but not if they walk for five minutes every hour.
When people sit, slack muscles do not contract to effectively pump blood to the heart. Blood can pool in the legs and affect the endothelial function of arteries, or the ability of blood vessels to expand from increased blood flow. Impaired endothelial function is an early marker of cardiovascular disease.
In the study, participants sat for three hours without moving their legs, while the functionality of the femoral artery was taken at baseline and every hour. This showed that the expansion of the femoral artery as a result of increased blood flow was impaired by as much as 50% after just one hour.
In another session, they again sat for three hours, but also walked on a treadmill for 5 minutes at a speed of 2 mph at the 30-minute mark, 1.5-hour mark and 2.5-hour mark. In this case, arterial function stayed the same throughout the session.
Thosar, S. S., Bielko, S. L., Mather, K. J., Johnston, J. D., & Wallace, J. P. (2015). Effect of Prolonged Sitting and Breaks in Sitting Time on Endothelial Function: Medicine & Science in Sports & Exercise, 47(4), 843–849. http://doi.org/10.1249/MSS.0000000000000479
A Czech study involving 146 people with mild to moderate risk of cardiovascular disease has found that moderate wine drinking was only protective in people who exercised.
Participants were randomly assigned to one year of moderate consumption of red wine (Pinot Noir) or white wine (Chardonnay-Pinot) from the same year and wine region of the Czech Republic. They had to keep a logbook on their consumption of wine and other alcoholic beverages, medication use, and amount and type of exercise. They were required to return the corks from the wine bottles to confirm that they had drank the wine rather than sold it.
The study was looking for a rise in HDL cholesterol, indicating a protective effect against cardiovascular disease. However, there was no change in HDL cholesterol levels by the end of the study in either the red or white wine groups. Nor did it appreciably affect blood glucose, triglycerides, or levels of inflammatory markers like C-reactive protein, although LDL cholesterol was lower in both groups while total cholesterol was lower only in the red wine group.
However, those participants who engaged in regular exercise at least twice a week did show an increase in HDL cholesterol, as well as a decrease in LDL and total cholesterol. This occurred in both red and white wine groups.
Of course, the study didn't include a control group of people engaging in regular exercise who didn't drink, so all we can really say (and it's certainly worth saying) is that moderate wine drinking doesn't seem to help protect against cardiovascular disease, and that despite all the hype around red wine, with its greater antioxidants and resveratol, there's no evidence it's any healthier than white wine.
Taborsky M, Ostadal P, Petrek M. A pilot randomized trial comparing long-term effects of red and white wines on biomarkers of atherosclerosis (in vino veritas: IVV trial). Bratisl Lek Listy. 2012;113(3):156-158.
A study looking at the workout habits of more than 55,000 individuals for 15 years has concluded that running can reduce a person’s all-cause mortality rate by 30% and cardiovascular mortality rate by 45%. This equated to a difference of about three years of life.
But the really exciting news is that people who ran less than an hour each week showed the same mortality benefits compared to those who ran more than three hours in each week. Note that this is more about running, say, ten minutes every day, than only running once a week for a longer time! You don't have to run fast, either. Those running more slowly (< 6 miles/hour) got the same benefits.
Not running had about the same negative effect on life expectancy as having hypertension.
Around 24% of the participants did some running. The average age was 44.
Lee D, Pate RR, Lavie CJ, Sui X, Church TS, Blair SN. Leisure-Time Running Reduces All-Cause and Cardiovascular Mortality Risk. J Am Coll Cardiol. 2014;64(5):472-481. doi:10.1016/j.jacc.2014.04.058.
A small study involving 15 adults with moderate-to-severe obstructive sleep apnea and 19 controls with mild or no sleep apnea has found that predicted peak oxygen uptake (VO2), a measure of aerobic physical fitness, was significantly lower in those people with moderate to severe obstructive sleep apnea. Moreover, the number of times a person stopped breathing, for 10-seconds or more, per hour of sleep, predicted 16% of the variability observed in the group's peak VO2.
People who suffer from apnea are more likely to be obese and thus would be expected to be less fit as well, but even compared to people with similar BMI, the apnea patients had a reduced aerobic fitness. It's suggested that the sleep apnea itself causes structural changes in muscle that contributes to exercise problems.
VO2 max measurements may be an early marker for those who are at higher risk of stroke and heart attack
Beitler JR, Awad KM, Bakker JP, Edwards BA, DeYoung P, Djonlagic I, Forman DE, Quan SF, Malhotra A. Obstructive sleep apnea is associated with impaired exercise capacity: a cross-sectional study. J Clin Sleep Med 2014;10(11):1199-1204.
Medical and genetic data from thousands of patients has enabled researchers to compare the similarity between patients with type 2 diabetes, revealing three distinctive clusters. These sub-types of type 2 diabetes are associated with different genetic variants, and have quite different health implications.
Subtype 1 patients were more likely to suffer from well-known diabetes problems with kidneys and eyes (diabetic nephropathy and diabetic retinopathy); subtype 2 was more likely to suffer from cancer and cardiovascular diseases; and subtype 3 was associated most strongly with cardiovascular diseases, neurological diseases, allergies, and HIV infections.
Li, L., Cheng, W.-Y., Glicksberg, B. S., Gottesman, O., Tamler, R., Chen, R., … Dudley, J. T. (2015). Identification of type 2 diabetes subgroups through topological analysis of patient similarity. Science Translational Medicine, 7(311), 311ra174-311ra174. http://doi.org/10.1126/scitranslmed.aaa9364
Data from 4.1 million British adults who were free of diabetes and cardiovascular disease at the start of the study has found that those with high blood pressure were almost 60% more likely to develop type 2 diabetes.
The strength of the association declined with increasing body mass index and age.
The finding strengthens previous research indicating that you are more at risk of diabetes if you have had high blood pressure, a heart attack or a stroke.
Emdin CA, Anderson SG, Woodward M, Rahimi K. Usual Blood Pressure and Risk of New-Onset Diabetes: Evidence From 4.1 Million Adults and a Meta-Analysis of Prospective Studies. J Am Coll Cardiol. 2015;66(14):1552-1562. doi:10.1016/j.jacc.2015.07.059.
A Canadian study involving 141 people with Type 2 diabetes, who ate either a low glycemic index diet that included bread made with canola oil, or a whole wheat diet known to reduce the risk of cardiovascular disease, found that those on the canola bread diet experienced both a reduction in blood glucose levels and a significant reduction in LDL, or "bad," cholesterol. Moreover, the canola bread diet seemed to have the most significant impact on people who needed help the most — those whose HbA1c test measuring blood glucose over the previous two or three months was highest.
On the other hand, those on the whole wheat diet seemed to have better blood flow after 12 weeks than those on the canola bread diet.
Jenkins, D. J. A., Kendall, C. W. C., Vuksan, V., Faulkner, D., Augustin, L. S. A., Mitchell, S., … Leiter, L. A. (2014). Effect of Lowering the Glycemic Load With Canola Oil on Glycemic Control and Cardiovascular Risk Factors: A Randomized Controlled Trial. Diabetes Care, 37(7), 1806–1814. http://doi.org/10.2337/dc13-2990
A ten-year study involving 4,207 older adults (73+) demonstrates that even in this older age group, modest physical activity was associated with a lower risk of cardiovascular disease. Among both men and women in good health:
- those who were more active had significantly lower risk of future heart attacks and stroke
- those who walked faster than three miles per hour had a 50% lower risk than those who walked at a pace of less than two mph (50%, 53%, 50% lower risk of coronary heart disease, stroke and total CVD, respectively)
- those who walked an average of seven blocks per day or more had a similar advantage compared to those who walked up to five blocks per week (36%, 54% and 47% lower risk of CHD, stroke and total CVD, respectively)
- those who engaged in leisure activities such as lawn-mowing, raking, gardening, swimming, biking and hiking, also had a lower risk of CHD, stroke and total CVD, compared to those who did not engage in leisure-time activities
Soares-Miranda, L., Siscovick, D. S., Psaty, B. M., Longstreth, W. T., & Mozaffarian, D. (2015). Physical Activity and Risk of Coronary Heart Disease and Stroke in Older Adults: The Cardiovascular Health Study. Circulation, CIRCULATIONAHA.115.018323. http://doi.org/10.1161/CIRCULATIONAHA.115.018323
A meta-analysis of 10 prospective studies involving a total of 136,265 older adults (average age 67) has found that having a high sense of purpose in life was significantly associated with lower mortality and cardiovascular events.
Most of the studies came from the United States or Japan. The US studies evaluated a sense of purpose or meaning in life, or "usefulness to others." The Japanese studies assessed the concept of ikigai, translated as "a life worth living."
Cohen, R., Bavishi, C., & Rozanski, A. (2016). Purpose in Life and Its Relationship to All-Cause Mortality and Cardiovascular Events: A Meta-Analysis. Psychosomatic Medicine, 78(2), 122–133. http://doi.org/10.1097/PSY.0000000000000274
A meta-analysis of 61 controlled trials has concluded that consuming tree nuts, such as walnuts, lowers total cholesterol, triglycerides, LDL cholesterol, and ApoB, the primary protein found in LDL cholesterol. Walnuts were investigated in 21 of the 61 trials, more than any other nut reviewed.
Consuming at least two servings (two ounces) per day of tree nuts had stronger effects on total cholesterol and LDL. The evidence also suggests that tree nut consumption may be particularly important for lowering the risk of heart disease in individuals with type 2 diabetes.
Walnuts have also been shown to reduce inflammation, and improve arterial function.
Del Gobbo, L., Falk, M.C., Feldman, R., Lewis, K., Mozaffarian, D. Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis and dose-response of 61 controlled intervention trials. Am J Clin Nutr.2015; doi: 10.3945/ajcn.115.110965.
Kris-Etherton P. Walnuts decrease risk of cardiovascular disease: a summary of efficacy and biologic mechanisms. J Nutr. 2014; 10.39:2S-8S.
Zhao G, Etherton TD, Martin KR, et al. Dietary alpha-linolenic acid reduces inflammatory and lipid cardiovascular risk factors in hypercholesterolemic men and women. J Nutr 2004; 134: 2991-2997.
A British study involving 165 healthy nonsmoking adults (aged 40–70) has found that a diet based on UK health guidelines could reduce risk of a heart attack or a stroke by up to a third, compared to a traditional British diet
The predicted risk of cardiovascular disease over the next 10 years for the participants was estimated to be about 8% in the men and 4% in the women. Participants followed their diets for 12 weeks. Those on the modified diet ate oily fish once a week, more fruit and vegetables, replaced refined with wholegrain cereals, swapped high-fat dairy products and meats for low-fat alternatives, and restricted their intake of added sugar and salt. Participants were asked to replace cakes and cookies with fruit and nuts and were also supplied with cooking oils and spreads high in monounsaturated fat.
The average body weight in the group on the modified diet fell by 1.3 kg; that in the control group rose by 0.6 kg. Waist circumference was 1.7 cm lower in the dietary group compared to the control group. There were also significant falls in systolic blood pressure/diastolic blood pressure (4.2/2.5 mm Hg for daytime and 2.9/1.9 mm Hg for night time) and average heart rate. Cholesterol fell by 8%. High-sensitivity C-reactive protein (a marker for inflammation) was 36% lower. There was no significant change in markers for insulin sensitivity. Much of the fall in blood pressure could be accounted for by the drop in sodium.
Reidlinger, D. P., Darzi, J., Hall, W. L., Seed, P. T., Chowienczyk, P. J., & Sanders, T. A. (2015). How effective are current dietary guidelines for cardiovascular disease prevention in healthy middle-aged and older men and women? A randomized controlled trial. The American Journal of Clinical Nutrition, 101(5), 922–930. http://doi.org/10.3945/ajcn.114.097352
A very large British study involving 1.1 million middle-aged women without prior vascular disease has found, over nine or so years, those who performed strenuous physical activity two to three times a week were about 20% less likely to develop heart disease, strokes or blood clots, compared to participants who reported little or no activity. However, those who reported doing strenuous activity daily had higher risk compared to those who only engaged in moderate amounts of activity.
Armstrong, M. E. G., Green, J., Reeves, G. K., Beral, V., & Cairns, B. J. (2015). Frequent Physical Activity May Not Reduce Vascular Disease Risk as Much as Moderate Activity Large Prospective Study of Women in the United Kingdom. Circulation, 131(8), 721–729. http://doi.org/10.1161/CIRCULATIONAHA.114.010296
A small study involving 45 healthy, overweight or obese adults aged 21-70 has found that a diet including a daily Hass avocado was more effective than other cholesterol-reducing diets. Participants followed each of three diets for five weeks: one containing 24% fats and two containing 34% fats, one of which included an avocado and the other a comparable amount of high oleic acid oils (e.g. olive oil). There was a two-week break between each diet.
The avocado diet decreased bad cholesterol by 13.5 mg/dL, while LDL was decreased by 8.3 mg/dL on the moderate-fat diet and by 7.4 mg/dL on the low-fat diet.
Wang, L., Bordi, P. L., Fleming, J. A., Hill, A. M., & Kris Etherton, P. M. (2015). Effect of a Moderate Fat Diet With and Without Avocados on Lipoprotein Particle Number, Size and Subclasses in Overweight and Obese Adults: A Randomized, Controlled Trial. Journal of the American Heart Association, 4(1), e001355. http://doi.org/10.1161/JAHA.114.001355
Data from a survey of 20,000 people across the UK has found that people who cycle, walk, or take public transport to work had a lower risk of being overweight than those who drove or took a taxi. People who walked to work were 40% less likely to have diabetes than those who drove and 17% less likely to have high blood pressure. Cyclists were around half as likely to have diabetes as drivers.
A Swedish study of some 4,000 60-year-olds has found that regular “non-exercise” physical activity such as gardening or DIY significantly reduced risk of heart attack or stroke, with those who were most active on a daily basis having a 27% lower risk of a heart attack or stroke and a 30% reduced risk of death from all causes. This was so regardless of how much regular formal exercise was taken. Regular physical activity was also associated with better waist circumference, high-density lipoprotein cholesterol and triglycerides in both sexes and with lower insulin, glucose and fibrinogen levels in men. Metabolic syndrome was also significantly less likely.
A mouse study has found that long-term physical activity increased levels of two proteins in the mitochondria of their heart. It’s thought this might help explain why regular exercise improves cardiovascular health.
Data from the very large U.S. National Health and Nutrition Examination Survey (NHANES), involving 23,168 people, has found a significant association between low dietary fiber intake and risk of metabolic syndrome, cardiovascular inflammation, and obesity.
Dietary fiber intake was also consistently below recommended intake levels: 38g per day for men aged 19-50 years, 30g per day for men 50 and over, 25g for women aged 19-50 years, and 21g per day for women over 50. Mean dietary fiber intake was only 16.2g per day across all groups.
A review of research from 1957 to the present has concluded that a whole diet approach, and specifically Mediterranean-style diets, has more evidence for reducing cardiovascular risk than strategies that focus exclusively on reduced dietary fat.
A study involving 44 middle-aged overweight men who consumed 70 grams of dark chocolate per day over two periods of four weeks, has found that dark chocolate helps restore flexibility to arteries while also preventing white blood cells from sticking to the walls of blood vessels. Both arterial stiffness and white blood cell adhesion are known factors that play a significant role in atherosclerosis.
A Finnish study has found that people who increased their intake of fatty fish to a minimum of 3–4 weekly meals had more large HDL cholesterol in their blood than people who were less frequent eaters of fish. Large HDL particles are believed to protect against cardiovascular diseases.
Middle-aged Japanese men living in Japan had lower incidence of coronary artery calcification, a predictor of heart disease, than middle-aged white men living in the United States, after accounting for risk factors such as smoking, cholesterol, alcohol consumption, diabetes and high blood pressure.
It’s suggested that the mixed results from studies looking at the effect of fish oil on cardiovascular health are due to the substantially lower intake of omega-3 fatty acids than that found in Japanese. The average dietary intake of fish by Japanese people living in Japan is nearly 100 grams each day, compared to the average American intake of 7-13 grams a day (about one serving a week).
Japanese-Americans had levels of coronary artery calcification higher than that of the rest of the US population.
A meta-analysis of 72 studies with over 600,000 participants from 18 nations has concluded that total saturated fatty acid, whether measured in the diet or in the bloodstream as a biomarker, was not associated with coronary disease risk. Nor was there any significant association between consumption of total monounsaturated fatty acids, long-chain omega-3 and omega-6 polyunsaturated fatty acids, and cardiovascular risk.
However, there were some significant associations between specific fatty acids. Eicosapentaenoic and docosahexaenoic acids (two main types of long-chain omega-3 polyunsaturated fatty acids), and arachidonic acid (an omega-6 fat) were each associated with lower coronary risk, while palmitic and stearic acids (found largely in palm oil and animal fats, respectively) were associated with higher risk, and margaric acid (a dairy fat) with lower risk.
Data from AREDS2, involving 4,203 older adults with age-related macular degeneration, has found that daily dietary supplements of either omega-3 polyunsaturated fatty acids (also found in fish) or lutein and zeaxanthin (nutrients found in green leafy vegetables) were not associated with reduced risk for cardiovascular disease (CVD).
Contradicting some earlier studies, new research using data from the very large and long-running Nurses' Health Study has found that calcium supplement intake was not associated with a higher risk of cardiovascular disease in women.
A review and meta-analysis of all international studies that compared the effects of higher versus lower added sugar consumption on blood pressure and lipids (blood fats or cholesterol) has uncovered evidence that sugar has a direct effect on risk factors for heart disease, and is likely to impact on blood pressure, independent of weight gain.
A study in which 136 older couples (average age 63) filled out questionnaires measuring their overall marriage quality and their perceived support from their spouse, has found that calcification in the coronary arteries was highest when both partners in the relationship viewed each other as offering ambivalent support (sometimes helpful, sometimes not). When only one partner felt this way, the risk was significantly less.
Overall marital satisfaction didn’t have a significant impact on this cardiovascular risk factor.
About 30% of individuals viewed their partner as delivering positive support, while 70% viewed their partner as ambivalent.
Two studies help explain why kidney disease increases the risk of cardiovascular diseases such as high blood pressure and vascular calcification. The mediator seems to be a hormone called FGF23, which is sensitive to the level of phosphates in the body.
Phosphate rich foods include processed cheese, Parmesan, cola, baking powder and most processed foods.
A study in which 157 healthy adult volunteers were asked to regulate their emotional reactions to unpleasant pictures, has found that those who showed greater brain activation when regulating their negative emotions also had higher blood levels of interleukin-6 (a marker for inflammation) and increased thickness of the carotid artery wall (a marker of atherosclerosis).
The finding helps explain why stress increases the risk for stroke and heart attack.
Type 2 diabetes greatly increases a person's risk of developing cardiovascular disease, but a new study shows that cardiovascular risk factors such as elevated blood pressure and cholesterol levels differ significantly between men and women with diabetes.
The study, involving 680 diabetics, found that blood pressure and LDL cholesterol levels were significantly higher in women, and women were significantly less likely to have these factors under control. Some 17% of men had control of these factors, compared to 6% of women.
The findings suggest that more effort should be put into informing women about cardiovascular risk factors and how to reduce them.
Journal article freely available at http://online.liebertpub.com/doi/full/10.1089/dia.2013.0329
A mouse study has found that introduction of oral bacteria into the bloodstream increased risk factors for atherosclerotic heart disease, including cholesterol and inflammation, suggesting that the same bacteria that cause gum disease also promotes heart disease. The findings are consistent with recent evidence that patients with gum disease are at higher risk for heart disease.
The findings were presented at the annual meeting of the American Society for Microbiology.