Ritva Järvinen

Flavonoid intake and coronary mortality in Finland: a cohort study

Abstract Objective: To study the association between dietary intake of flavonoids and subsequent coronary mortality. Design: A cohort study based on data collected at the Finnish mobile clinic health examination survey from 1967-72 and followed up until 1992. Settings: 30 communities from different parts of Finland. Subjects: 5133 Finnish men and women aged 30-69 years and free from heart disease at baseline. Main outcome measure: Dietary intake of flavonoids, total mortality, and coronary mortality. Results: In women a significant inverse gradient was observed between dietary intake of flavonoids and total and coronary mortality. The relative risks between highest and lowest quarters of flavonoid intake adjusted for age, smoking, serum cholesterol concentration, blood pressure, and body mass index were 0.69 (95% confidence interval 0.53 to 0.90) and 0.54 (0.33 to 0.87) for total and coronary mortality, respectively. The corresponding values for men were 0.76 (0.63 to 0.93) and 0.78 (0.56 to 1.08), respectively. Adjustment for intake of antioxidant vitamins and fatty acids weakened the associations for women; the relative risks for coronary heart disease were 0.73 (0.41 to 1.32) and 0.67 (0.44 to 1.00) in women and men, respectively. Intakes of onions and apples, the main dietary sources of flavonoids, presented similar associations. The relative risks for coronary mortality between highest and lowest quarters of apple intake were 0.57 (0.36 to 0.91) and 0.81 (0.61 to 1.09) for women and men, respectively. The corresponding values for onions were 0.50 (0.30 to 0.82) and 0.74 (0.53 to 1.02), respectively. Conclusion: The results suggest that people with very low intakes of flavonoids have higher risks of coronary disease. Key messages Key messages The protective effect of flavonoids was associated with a diet high in intake of apples and onions The effect may be mediated through prevention of oxidation of low density lipoproteins but other mechanisms could be involved Flavonoids offer an explanation for the suggested beneficial effect of fruits and vegetables in coronary heart disease Further studies should concentrate on the effects of various flavonoid compounds and on populations with different intakes

Risk of colorectal and other gastro‐intestinal cancers after exposure to nitrate, nitrite and N‐nitroso compounds: a follow‐up study

N‐nitroso compounds are potent carcinogens detected in foodstuffs. The importance of dietary nitrosamines in relation to human cancer development is, however, uncertain. We studied the relationship between intake of nitrates, nitrites and N‐nitrosodimethylamine (NDMA) and risk of cancers of the gastro‐intestinal tract in a cohort of 9,985 adult Finnish men and women. During a follow‐up period of up to 24 years, 189 gastro‐intestinal cancer cases were diagnosed in the cohort, initially free from cancer. Intake of nitrate, nitrite and NDMA were estimated, based on food‐consumption data from a 1‐year dietary history interview covering the total diet of the participants. A significant positive association was observed between intake of NDMA and subsequent occurrence of colorectal cancer with a relative risk (RR) between the highest and lowest quartiles of intake of 2.12 [95% confidence interval (CI) 1.04–4.33]. Of various sources of N‐nitroso compounds, intake of smoked and salted fish was significantly (RR = 2.58, 95% CI 1.21 − 5.51) and intake of cured meat was non‐significantly (RR = 1.84, 95% CI 0.98– 3.47) associated with risk of colorectal cancer. No similar association was observed for intake of other fish or other meat. No significant associations were observed between NDMA intake and cancers of the head and neck combined or of the stomach or between nitrate or nitrite intake and risk of cancers of the gastro‐intestinal tract. Our results are in line with the idea that N‐nitroso compounds can induce colorectal cancer in humans. Int. J. Cancer 80:852–856, 1999.

Dietary intakes of nitrate, nitrite and NDMA in the Finnish Mobile Clinic Health Examination Survey.

Concern about potential health hazards of nitrate, nitrite and N-nitroso compounds necessitates calculations of exposures to these compounds and their distribution in normal populations. This study describes dietary intake of nitrate (NO3-), nitrite (NO2-) and N-nitrosodimethylamine (NDMA) among 5304 adult men and 4750 women, who participated in the Finnish Mobile Clinic Health Examination Survey in 1967-72. Food consumption data for each individual over the preceding year were collected by a dietary history interview. Intakes of nitrate, nitrite and NDMA from vegetables, fruits, cheese, meat and fish products were calculated using available values mainly derived from Finland and other countries in northern Europe. Nitrate and nitrite from drinking water were not included in the study. Mean daily dietary intake of nitrate was 77 mg, of nitrite 5.3 mg, and of NDMA 0.05 microgram respectively. Intake of NDMA from beer, estimated in a part of the study population, was 0.07 microgram per day. More than 90% of dietary nitrate was derived from vegetables, including potatoes. Nitrite was mainly provided by cured meat products. Cured meat products and smoked and salted fish were important food sources of NDMA. The total daily intake of nitrate was similar in men and women, whereas intakes of nitrite and NDMA were higher in men than in women. The diet of farmers was characterized by lower amounts of nitrate, nitrite and NDMA, whereas white collar workers and those employed in industry had higher intakes. Current smokers were exposed to higher dietary intakes of nitrate, nitrite and NDMA than non-smokers. Intakes of dietary nitrate, nitrite and NDMA estimated on an individual level are suggested to be useful in evaluating the health effects of these compounds in epidemiological studies.

Diet and breast cancer risk in a cohort of Finnish women

The associations between dietary antioxidant vitamins, dietary fiber, and selected foods and risk of breast cancer were studied in 4697 initially cancer-free women, aged 15 years or older. At baseline (1967-1972) the women were interviewed for total habitual diet over the preceding year. During a 25-year follow-up period 88 breast cancer cases were diagnosed. There was a significant inverse gradient between milk consumption and occurrence of breast cancer, whereas higher consumption of fried meat was associated with increased risk of breast cancer. No significant relationships were found between the intakes of vitamin E, vitamin C, beta-carotene, lycopene, lutein or dietary fiber and the occurrence of breast cancer.

Plant foods and the risk of cerebrovascular diseases: a potential protection of fruit consumption

Studies on the association between plant foods and cerebrovascular diseases have given contradictory results suggesting the existence of some effect-modifying factors. The present study determines whether the consumption of plant foods (i.e. fruits and berries, vegetables, and cereals) predicts a decreased cerebrovascular disease incidence in a population with low fruit and vegetable and high wholegrain intake. This cohort study on 3932 men and women was based on data from the Finnish Mobile Clinic Health Examination Survey, conducted in 1968-72. The participants were 40-74 years of age and free of cardiovascular diseases at baseline. Data on the plant food consumption were derived from a 1-year dietary history interview. During a 24-year follow-up 625 cases of cerebrovascular diseases occurred, leading to either hospitalisation or death. An inverse association was found between fruit consumption and the incidence of cerebrovascular diseases, ischaemic stroke and intracerebral haemorrhage. The adjusted relative risks (RR) between the highest and lowest quartiles of intake of any cerebrovascular disease, ischaemic stroke and intracerebral haemorrhage were 0.75 (95 % CI 0.59, 0.94), 0.73 (95 % CI 0.54, 1.00) and 0.47 (95 % CI 0.24, 0.92), respectively. These associations were primarily due to the consumption of citrus fruits and occurred only in men. Total consumption of vegetables or cereals was not associated with the cerebrovascular disease incidence. The consumption of cruciferous vegetables, however, predicted a reduced risk of cerebrovascular diseases (RR 0.79; 95 % CI 0.63, 0.99), ischaemic stroke (RR 0.67; 95 % CI 0.49, 0.92) and intracerebral haemorrhage (RR 0.49; 95 % CI 0.25, 0.98). In conclusion, the consumption of fruits, especially citrus, and cruciferous vegetables may protect against cerebrovascular diseases.

Intake of fish and long-chain n −3 fatty acids and the risk of coronary heart mortality in men and women

This prospective study investigated the relationship between the consumption of fish and intake of long-chain n-3 fatty acids and the risk of coronary heart mortality in 2775 men and 2445 women aged from 30 to 79 years who were free of CHD and had participated in a health examination survey from 1967 to 1972. In total, 335 men and 163 women died of CHD during a follow-up until the end of 1992. A dietary history interview method provided data on habitual consumption of fish and other foods over the preceding year at baseline. The intakes of long-chain n-3 fatty acids were calculated on the basis of food composition values of Finnish foods. Higher consumption of fish was associated with a decreased risk of CHD among women, whereas no significant association was seen among men. The relative risk between the highest and the lowest quintile for fish consumption was 1.00 (95 % CI 0.70, 1.43; P for trend 0.83) for men and 0.59 (95 % CI 0.36, 0.99; P for trend 0.02) for women in analysis adjusting for age, energy intake, geographical area, BMI, serum cholesterol, blood pressure, smoking, occupation and diabetes; however, after adjustment for dietary confounders this association was no longer significant. The intake of n-3 fatty acids was not significantly associated with the risk of CHD in either men or women. In conclusion, our results for women are in line with the suggested protective effect of fish consumption against CHD but a similar association was not, however, found in men.

Serum Fatty Acids and Breast Cancer Incidence

Fatty acid composition of the diet may be essential to the development of breast cancer. We studied the ability of several fatty acids of serum total lipids to predict breast cancer incidence in a case-control study nested within a longitudinal population study. The proportions of fatty acids in serum total lipids were determined from stored serum samples collected at baseline for 127 incident breast cancer cases and 242 matched controls. Women with a higher proportion of total polyunsaturated fatty acids (PUFAs) in serum had a reduced risk of breast cancer. The odds ratio (OR) between the highest and lowest tertiles of serum PUFA was 0.31 (95% confidence interval, CI = 0.12-0.77). This association was mainly due to n-6 PUFAs and especially to linoleic acid. The ORs were 0.35 (CI = 0.14-0.84) and 0.29 (CI = 0.12-0.73), respectively. Of the monounsaturated fatty acids (MUFAs), higher trans-11-18:1 levels were related to an increased breast cancer risk (OR = 3.69, CI = 1.35-10.06). The association was stronger in postmenopausal than in premenopausal women. The present study suggests that higher serum proportions of the n-6 PUFA linoleic acid and lower proportions of the MUFA trans-11-18:1 fatty acid predict a reduced incidence of breast cancer.

Dietary cholesterol, fatty acids, and the risk of lung cancer among men

The relation between dietary cholesterol and fatty acids and the incidence of lung cancer was studied among 4,538 Finnish men aged 20-69 years and initially free of cancer. During 20 years of follow-up, 117 lung cancer cases were diagnosed. Cholesterol intake was not associated with lung cancer risk, the age-, smoking-, and energy-adjusted relative risk between the lowest and highest tertiles being 1.0 [95% confidence interval (CI) = 0.6-1.9]. The intake of saturated fatty acids was nonsignificantly related with lung cancer incidence, the relative risk for the lowest compared with the highest tertile being 1.6 (CI = 0.8-3.2). The association was stronger among smokers than among nonsmokers, the relative risks being 2.1 (CI = 1.0-4.3) and 1.3 (CI = 0.4-4.1), respectively. The relative risk among smokers, however, decreased to 1.5 after adjustment for the amount they smoked. In the total cohort, there was a significantly elevated risk of lung cancer among men with a high intake of butter, one of the main sources of saturated fatty acids, the relative risk being 1.9 (CI = 1.1-3.2). The present data do not confirm previous results suggesting that dietary cholesterol predicts the occurrence of lung cancer among men. The association between intake of saturated fatty acids and lung cancer observed in the present study may be partly due to heavy smoking among high consumers of saturated fat.

Alcohol consumption and bone mineral density in elderly women.

OBJECTIVE Findings regarding alcohol consumption and bone mineral density (BMD) in elderly women have been inconsistent. The objective of the present study was to explore the association of alcohol intake with BMD in elderly women. DESIGN This cohort study included women from the population-based Kuopio Osteoporosis Risk Factor and Prevention - Fracture Prevention Study (OSTPRE-FPS). Alcohol intake and potential confounders were assessed at baseline and after 3 years of follow-up using a lifestyle questionnaire. In addition, an FFQ was distributed in the third year to measure dietary intake, including alcohol. Women underwent BMD measurements at the femoral neck and lumbar spine at baseline and after 3 years of follow-up. SETTING Kuopio Province, Finland. SUBJECTS Three hundred elderly women (mean age 67·8 years) who provided both BMD measurements and FFQ data. RESULTS Alcohol consumption estimated from the FFQ and lifestyle questionnaire was significantly associated with BMD at both measurement sites after adjustment for potential confounders, including lifestyle and dietary factors (P < 0·05). Using the FFQ, women drinking >3 alcoholic drinks/week had significantly higher BMD than abstainers, 12·0 % at the femoral neck and 9·2 % at the lumbar spine. Results based on the lifestyle questionnaire showed higher BMD values for all alcohol-consuming women at the femoral neck and for women drinking 1-3 alcoholic beverages/week at the lumbar spine, compared with non-users. CONCLUSIONS The results from OSTPRE-FPS suggest that low to moderate alcohol intake may exert protective effects on bone health in elderly women.

Fish consumption and the incidence of cerebrovascular disease

Studies of the beneficial role of fish consumption in the prevention of CVD are not consistent in their findings, particularly those studies that focus on the risk of stroke. The aim of the present study is to investigate the relationship between the consumption of different types of fish and the subsequent incidence of cerebrovascular disease (CVA). We prospectively evaluated the association between consumption of different types of fish and CVA in 3958 men and women aged 40-79 years who were free of heart disease and had participated in a health examination survey from 1967 to 1972. A total of 659 incident cases of CVA occurred during a follow-up until the end of 1994. A dietary history interview method provided data on habitual consumption of fish and other foods over the preceding year at baseline. Total fish intake did not predict CVA, but consumption of salted fish suggested an increased risk of intracerebral haemorrhage. The relative risk of intracerebral haemorrhage between the highest tertile of salted fish consumption and non-consumers was 1.98 (95 % CI 1.02, 3.84; P for trend = 0.06) after adjustment for age, sex, energy intake, smoking, BMI, physical activity, geographic area, occupation, diabetes, use of post-menopausal hormones, serum cholesterol, hypertension, and consumptions of butter, vegetables, fruits and berries. The relationship between fish consumption and stroke risk is not straightforward. How the fish is prepared for consumption may play an important role, affecting the association.