ABSTRACT
It has been suggested that dietary linoleic and gamma-linolenic acid may be hypotensive. Fat enriched diets increase blood pressure, and the effects of linoleic and linolenic acids on this increase have been investigated. After a control period on a low fat diet, rabbits were given four fat enriched diets containing different proportions of linoleic, gamma-linolenic and alpha-linolenic acids for 8 weeks, and returned to the low fat control diet for 3 weeks. Blood pressures were measured non-invasively every day. Blood pressures increased from the 4th week of fat feeding. The blood pressure increase at 8 weeks was 10%, 13%, 15% and 14% respectively for primrose, starflower, safflower and olive oils (all P less than 0.001). Return to the low fat control diet for 3 weeks restored blood pressures to near control values. These results do not support the suggestion that either linoleic or gamma-linolenic acids are effective antihypertensive agents.
Subject(s)
Hypertension/chemically induced , Linoleic Acids/therapeutic use , Linolenic Acids/therapeutic use , Animals , Blood Pressure/drug effects , Dietary Fats , Hypertension/drug therapy , Plant Oils , Rabbits , gamma-Linolenic AcidABSTRACT
The blood pressures of 252 men and 250 women, living in both urban and rural Zimbabwe, were measured on three separate occasions. Food and alcohol intakes were determined using a 3-day weighed diet survey checked by means of a detailed interview. Anthropometric data were also collected. No relationship was found between mean blood pressures and the alcohol intake for any socioeconomic group. Using only the first of the three blood pressure measurements, a correlation between systolic pressure and alcohol intake was found for white males (r = 0.234, P less than 0.05), and just missed statistical significance (r = 0.156, P = 0.065) for black middle class males. No relationship was found between blood pressure and alcohol consumption for black working class males, or for females. Epidemiological evidence suggests that alcohol consumption is associated with increased blood pressure. However, a convincing physiological mechanism is lacking. It is suggested that psychological factors may be partly responsible for this relationship.
Subject(s)
Alcohol Drinking/physiology , Blood Pressure , Adult , Black or African American , Black People , Energy Intake , Female , Humans , Male , Socioeconomic Factors , ZimbabweABSTRACT
The diets of various Zimbabweans: black and white, middle class and working class, rural and urban are compared. Urban volunteers were recruited from a number of business premises in Harare, the capital of Zimbabwe. Rural volunteers were recruited at several villages and cooperative farms averaging 200 km from the capital. The composition of the diets, expressed as per cent total energy obtained from fat, carbohydrate, and protein, and megajoules (MJ) energy respectively, were: white middle class, 40 per cent, 39 per cent, 16 per cent, 9.35 MJ (M), 6.65 MJ (F); black middle class, 30 per cent, 49 per cent, 17 per cent, 10.96 MJ (M), 6.60 MJ (F); black urban working class, 25 per cent, 53 per cent, 17 per cent, 10.96 MJ (M), 7.53 MJ (F); black urban middle class, 23 per cent, 54 per cent, 16 per cent, 10.88 MJ (M), 7.67 MJ (F); and black rural working class, 22 per cent, 58 per cent, 17 per cent, 9.43 MJ (M), 8.02 MJ (F). The results suggest that the sample of Zimbabweans studied here are well nourished, even by the standards of developed countries. Anthropometric data supports this, showing that Zimbabwean peasants are both taller and heavier than their counterparts in Malawi, Uganda, Tanzania, and Kenya, all members of the Bantu cultural group in East and Central Africa.
Subject(s)
Diet Surveys , Nutrition Surveys , Adult , Black or African American , Alcohol Drinking , Anthropometry , Black People , Dietary Carbohydrates/metabolism , Dietary Fats/metabolism , Dietary Proteins/metabolism , Energy Metabolism , Female , Humans , Male , Rural Population , Sex Factors , Socioeconomic Factors , Urban Population , White People , ZimbabweABSTRACT
Vegetarians have lower blood pressures than omnivores. Dietary protein may be partly responsible. Human volunteers, whose normal diet contained little soya protein, were given soya based foods to replace some of the meat in their diet. During this period over 20% of the total protein intake was derived from soya, however blood pressures remained unchanged. Rabbits were given diets based on either soya, casein, or fish protein. The animals' diets were then changed to one of the other protein sources. During the subsequent 3 weeks, small increases in blood pressure were seen in the casein and soya groups. When rabbits were given fat enriched diets, blood pressures rose but the increase was independent of the type of protein in the diet. It is concluded that the type of protein consumed is unlikely to account for the blood pressure differences between vegetarians and omnivores. Arguments are presented suggesting that other dietary components, such as fat or fibre may be responsible.
