Although the TCM use of goji berry also includes the leaves and bark of the plant, this review will discuss the potential benefits of the fruit on eye health. In addition to a robust amount of Z, goji berries contain modest amounts of β-cryptoxanthin, β- carotene, neoxanthin and L. The Z and L content among different varieties of dried goji berries cultivated in Ningxia province ranged from 25 to 152 mg/100g, and 0.3 to 1.9 mg/100g, respectively. According to the United States Department of Agriculture food database, one serving of goji berries is 28 g, which would provide up to 42.6 mg of L + Z, depending on the cultivar. Moreover, the predominant form of Z in goji berries is a dipalmitate, found with a diester linkage. The ratio of Z dipalmitate to total carotenoids was up to 55% and 88%, in fresh and dried goji berry fruit, respectively. This esterified form of Z showed a significantly higher intestinal absorption than monoester and free Z due to the high efficacy of hydrolysis, blueberry grow pot mainly by carboxyl ester lipase. Plasma Z was significantly increased in individuals consuming 15g goji berries daily for 28 days in comparison to those on a habitual diet.
Participants consuming 5 mg of Z dipalmitate extracted from goji berries showed a higher plasma Z concentration than when they consumed the same amount as unesterified Z over a nine to 24 hour period. The high Z content of goji berries has been proposed as a dietary source to reduce the risk of AMD, although studies are limited.150 In one study, circulating Z levels were significantly higher in healthy older individuals who consumed 10 mg of Z extract from goji berries daily for 90 days. No change in macular pigmentation or soft drusen was observed, but MPOD was not measured. In an uncontrolled trial, individuals with early stage AMD who consume a beverage containing 12 mg of L and 2 mg of Z derived from marigold flower and goji berry, respectively, daily for five months, showed higher circulating levels of L and Z, lower intraocular pressures, and better best-corrected visual acuity scores. Unfortunately, the study lacked a control group, did not test the effect of Z separately, and did not clarify whether the form of Z extracted from goji berry was the dipalmitate. Another study investigating the effects of an herbal formula among healthy adults with dry eyes noted that those chewing tablets containing L , Z , extracts from blackcurrant, chrysanthemum, and goji berry showed dose-dependent reductions in eye fatigue symptoms, improved tear secretion as well as MPOD, compared to placebo.
The basis of this formula was derived from TCM, so the multi-component formulation could not directly inform the role of any single ingredient. A study in patients with early AMD reported that the MPOD was significantly higher in those consuming 25 g/day of goji berries for 90 days, compared to their baseline levels and to a habitual diet control group. The BCVA was also significantly improved in the goji berry group compared to their baseline values. We recently reported that MPOD and skin carotenoid scores were increased in healthy middle-aged individuals consuming 28 g/day of goji berries five times a day for 90 days compared to a group taking a supplement with 6 mg of L and 4 mg of Z. These results illustrate that MPOD levels can increase in healthy individuals even without early signs of AMD. While these results are encouraging, longer intervention periods with a larger number of participants are necessary. In addition to AMD, goji berries have been studied as a therapy for retinitis pigmentosa, an inherited retinal disease. Patients who consume 0.35 g/d of LBP for 12 months showed a significant improvement in visual acuity and macular thickness, compared to control subjects who did not consume L or Z. Examples of human studies that evaluated the effects of supplements containing goji berries on retinal health are shown in Table 1. Based on preclinical evidence, potential benefits of goji berry intake on glaucoma and diabetic retinopathy may also exist. Goji berry extract ameliorated the high glucose-induced blood-retinal barrier disruption in human retinal pigment epithelial cells.
Studies reported that LBP showed significant neuroprotective effects over retinal ganglion cells in male C57BL/6N mice and Sprague-Dawley rats with ocular hypertension. In db/db mice, goji berry extract restored the thickness of the retina, the ganglion cell number, and the integrity of RPE after daily intake over eight weeks. Although research on the upper limit of goji berry intake is scarce, goji berry allergy risk has been associated with the existence of cross-reactivity to nonspecific lipid transfer proteins from peaches, tomatoes, tobacco, tree nuts, and select pollens. In addition, bleeding symptoms after consuming goji berry juice, tea, or wine have been described in case reports among patients taking warfarin, an anticoagulant medicine. Although the potential value of foods high in L and Z during pregnancy and lactation has been discussed above, the utilization of goji berry products during these unique periods in a woman’s life needs special caution. Clinical studies of goji berries on eye health have been conducted primarily in Asia, with emerging research reported from Italy, Lithuania, and Switzerland. Potential gene-nutrient interactions must be considered when comparing results from Asian with Caucasian populations. Over the past decade, the number of H-2A guest workers employed on California farms increased more than tenfold, so that almost 44,000 farm jobs were certified to be filled by H-2A workers in fiscal year 2022 . During FY2020, two-thirds of the H-2A jobs certified in California were in crop support services. Most crop support jobs were with farm labor contractors , but one sixth were hired directly by fruit producers. Almost 10% of the H-2A workers were hired directly by vegetable producers . Until the 2008–2009 recession, most H-2A workers were in southeastern states such as Florida. However, the slowdown in migration of undocumented individuals after 2008–2009, hydroponic bucket combined with a stable demand for farm workers and the aging and settling of undocumented workers who arrived before 2008–2009, contributed to the rapid growth in the H-2A program in the three Pacific Coast states that employ half of U.S. farm workers, a third of whom work in California.This paper analyzes agricultural employment data from the California Employment Development Department and the Quarterly Census of Employment and Wages to understand changing patterns of farm worker employment in the 21st century. The data show that seasonality is declining in most regions and commodities, primarily because of higher employment during the winter months, which may reflect more winter pruning jobs and fewer summer harvesting jobs. Second, the data emphasize the increasing importance of non-farm crop support employers, mostly labor contractors, who bring workers to farms to perform specific tasks. More farms appear to be developing a year-round workforce that is hired directly and supplemented when needed with workers brought to farms by labor contractors, including H-2A guest workers . California requires all employers who pay $100 or more in wages to enroll in the state’s unemployment insurance system and pay taxes of 1.5% to 6.2% on the first $7,000 of each employee’s wages to cover the cost of unemployment benefits for laid-off workers . Employers also report their employment for the payroll period that includes the 12th of the month. Summing these monthly employment totals and dividing by 12 months generates average employment, also referred to as year-round equivalent jobs.
The monthly employment measures allow us to determine the peak and trough employment months. Agricultural employment, as defined by the North American Industry Classification System , peaked at 470,000 in May 2020 and was 346,000 in March 2020, generating a peak-trough ratio of 1.4. More than 470,000 workers are employed on California farms sometime during the year. Workers who are employed only in payroll periods that do not include the 12th of the month, such as those who work only during the first, third, or fourth weeks of the month, are excluded from average employment. In 2016, when California’s agricultural employment averaged 425,000, almost a million unique Social Security Numbers were reported by the state’s agricultural employers, suggesting 2.3 unique workers for each year-round equivalent job . California became the leading farm state in terms of sales in 1949, when Los Angeles County led the United States in farm sales . The state’s population doubled between 1950 and 1970, from 10 million to 20 million, and agricultural sales grew fastest in the San Joaquin Valley after water projects allowed more acres to be irrigated and suburbanization reduced the availability of farmland in coastal areas. Citrus and dairy farms in Southern California migrated north to SJV, while tree fruit farms moved from the urbanizing Bay Area to the San Joaquin and Sacramento valleys . Three SJV counties — Fresno, Kern and Tulare — accounted for 20% of California farm sales in 1949, a third in 2000, and almost half of the state’s farm sales in 2020 . Some crops that were already concentrated in the Sacramento and San Joaquin valleys expanded in acreage. For example, there were 90,000 bearing acres of almonds in 1950, almost 150,000 acres in 1970, 500,000 acres by 2000, and 1.3 million acres in 2022. Most of this additional almond acreage was in the San Joaquin Valley. New orchards and dairies in the San Joaquin and Sacramento valleys were often larger and more efficient than the coastal farms they replaced, and their higher productivity was reflected in rising yields. Average yields of many fruits and vegetables doubled and tripled over the past three decades; bell peppers and cantaloupes are examples. Yield rose over 50% to 33 tons an acre for strawberries . The major change in California crop farming over the past half-century has been the rising share of high value fruits, nuts, vegetables, and melons, as well as horticultural specialties such as flowers and plants, in the state’s farm sales. In 1960, the value of fruit, vegetable, and horticultural commodities was two-thirds of the total value of California crops; since 2000, FVH commodities have accounted for over 90% of the value of California crops, reflecting growing consumer demand for fresh produce and nursery plants . Cotton was California’s most valuable crop in 1950; by 2000, cotton was the sixth most valuable crop, and by 2020 cotton was no longer among the state’s top 20 crops. The demand for FVH commodities rises with income, and rising farmland prices encouraged individuals and investors to buy farmland as a hedge against inflation in the 1970s, a decade in which the value of California farmland more than doubled . Higher interest rates in the 1980s led to a farm financial crisis that was more severe in midwestern states than in California, but encouraged some oil firms and conglomerates to sell their California farmland. The data in table 1 show that California’s farm sales almost tripled in three decades, and that fruit and nut sales almost quintupled. The value of the state’s vegetables and melons doubled, as did the value of greenhouse and nursery crops. The state’s farm sales were $17.8 billion in 1990, including $4.4 billion worth of fruits and nuts and $3.9 billion worth of vegetables. Farm sales were $27.2 billion in 2000, including $7.3 billion worth of fruits and nuts, $6.2 billion worth of vegetables, and $2.8 billion worth of greenhouse and nursery commodities. This rose to $37.5 billion in 2010, including $13.5 billion worth of fruits and nuts, $6.7 billion worth of vegetables, and $3.8 billion worth of greenhouse and nursery commodities. In 2020, farm sales were $49.1 billion, including $20.6 billion worth of fruits and nuts, $7.8 billion worth of vegetables, and $6.3 billion worth of greenhouse and nursery commodities. In real or inflation-adjusted terms, California farm sales rose by 40% over 30 years, and fruit and nut sales by 140%, while vegetable and nursery sales were little changed.Many FVH commodities are labor intensive, so expanding production increases the employment of farm workers. These are non-farm businesses that bring workers to farms to accomplish specific tasks. For example, farmers may rely on labor contractors to bring crews of workers for a few weeks to prune, thin, or harvest their crops. Contractors may be the sole employers of the workers they bring to farms under some labor laws, such as unemployment insurance and workers’ compensation, and joint employers with farms under others, such as the Agricultural Labor Relations Act.